diff --git a/library/Makefile b/library/Makefile
index 086720cb..a8483087 100644
--- a/library/Makefile
+++ b/library/Makefile
@@ -19,7 +19,9 @@ CC		:= gcc
 LINKER		:= gcc
 
 # general compiler flags
-WFLAGS		:= -Wall -Wextra -Werror=float-equal -Wuninitialized -Wunused-variable -Wdouble-promotion
+WFLAGS		:= -Wall -Wextra -Werror=float-equal -Wuninitialized \
+	-Wunused-variable -Wdouble-promotion -pedantic -Wmissing-prototypes \
+	-Wmissing-declarations -Werror=undef
 CFLAGS		:= -g -fPIC -I $(INCLUDEDIR)
 OPT_FLAGS	:= -O1
 LDFLAGS		:= -lm -lrt -pthread -shared -Wl,-soname,$(SONAME)
diff --git a/library/include/rc/adc.h b/library/include/rc/adc.h
index 459e5f7a..33c56445 100644
--- a/library/include/rc/adc.h
+++ b/library/include/rc/adc.h
@@ -43,7 +43,7 @@ extern "C" {
  *
  * @return     0 on success, -1 on failure.
  */
-int rc_adc_init();
+int rc_adc_init(void);
 
 /**
  * @brief      Cleans up the ADC subsystem.
@@ -52,7 +52,7 @@ int rc_adc_init();
  *
  * @return     0 on success, -1 on failure.
  */
-int rc_adc_cleanup();
+int rc_adc_cleanup(void);
 
 /**
  * @brief      reads the raw integer ADC value for a particular channel
@@ -77,14 +77,14 @@ double rc_adc_read_volt(int ch);
  *
  * @return     voltage of battery or -1 on failure
  */
-double rc_adc_batt();
+double rc_adc_batt(void);
 
 /**
  * @brief      Reads the voltage of the 9-18v DC jack
  *
  * @return     Voltage at DC jack or -1 on failure
  */
-double rc_adc_dc_jack();
+double rc_adc_dc_jack(void);
 
 
 
diff --git a/library/include/rc/bmp.h b/library/include/rc/bmp.h
index 48057518..45d4aa99 100644
--- a/library/include/rc/bmp.h
+++ b/library/include/rc/bmp.h
@@ -95,7 +95,7 @@ int rc_bmp_set_sea_level_pressure_pa(double pa);
  *
  * @return     0 on success, -1 on failure
  */
-int rc_bmp_power_off();
+int rc_bmp_power_off(void);
 
 
 /**
@@ -116,4 +116,4 @@ int rc_bmp_read(rc_bmp_data_t* data);
 
 #endif // RC_BMP_H
 
-/** @}  end group Barometer */
\ No newline at end of file
+/** @} end group Barometer */
\ No newline at end of file
diff --git a/library/include/rc/button.h b/library/include/rc/button.h
index 7da92e4f..a91e911f 100644
--- a/library/include/rc/button.h
+++ b/library/include/rc/button.h
@@ -55,7 +55,7 @@ int rc_button_init(int chip, int pin, char polarity, int debounce_us);
  * @brief      Closes all button handlers. Call at the end of your program
  * before returning.
  */
-void rc_button_cleanup();
+void rc_button_cleanup(void);
 
 
 /**
diff --git a/library/include/rc/cpu.h b/library/include/rc/cpu.h
index 03bffa72..9a2461c5 100644
--- a/library/include/rc/cpu.h
+++ b/library/include/rc/cpu.h
@@ -53,14 +53,14 @@ int rc_cpu_set_governor(rc_governor_t gov);
  *
  * @return     frequency in hz
  */
-int rc_cpu_get_freq();
+int rc_cpu_get_freq(void);
 
 /**
  * @brief      Prints the current frequency to the screen. For example "600mhz".
  *
  * @return     0 on success or -1 on failure.
  */
-int rc_cpu_print_freq();
+int rc_cpu_print_freq(void);
 
 
 
diff --git a/library/include/rc/deprecated.h b/library/include/rc/deprecated.h
index a8d72cc4..943e39fe 100644
--- a/library/include/rc/deprecated.h
+++ b/library/include/rc/deprecated.h
@@ -20,9 +20,9 @@ extern "C" {
 
 
 
-int rc_initialize() __attribute__ ((deprecated));
+int rc_initialize(void) __attribute__ ((deprecated));
 
-int rc_cleanup() __attribute__ ((deprecated));
+int rc_cleanup(void) __attribute__ ((deprecated));
 
 typedef enum rc_button_state_t {
 	RELEASED,
@@ -33,21 +33,21 @@ int rc_set_pause_pressed_func(void (*func)(void)) __attribute__ ((deprecated));
 int rc_set_pause_released_func(void (*func)(void)) __attribute__ ((deprecated));
 int rc_set_mode_pressed_func(void (*func)(void)) __attribute__ ((deprecated));
 int rc_set_mode_released_func(void (*func)(void)) __attribute__ ((deprecated));
-rc_button_state_t rc_get_pause_button() __attribute__ ((deprecated));
-rc_button_state_t rc_get_mode_button() __attribute__ ((deprecated));
+rc_button_state_t rc_get_pause_button(void) __attribute__ ((deprecated));
+rc_button_state_t rc_get_mode_button(void) __attribute__ ((deprecated));
 
 
 int rc_get_encoder_pos(int ch) __attribute__ ((deprecated));
 int rc_set_encoder_pos(int ch, int value) __attribute__ ((deprecated));
 
-int rc_enable_motors() __attribute__ ((deprecated));
-int rc_disable_motors() __attribute__ ((deprecated));
+int rc_enable_motors(void) __attribute__ ((deprecated));
+int rc_disable_motors(void) __attribute__ ((deprecated));
 int rc_set_motor(int motor, float duty) __attribute__ ((deprecated));
 int rc_set_motor_all(float duty) __attribute__ ((deprecated));
 int rc_set_motor_free_spin(int motor) __attribute__ ((deprecated));
-int rc_set_motor_free_spin_all() __attribute__ ((deprecated));
+int rc_set_motor_free_spin_all(void) __attribute__ ((deprecated));
 int rc_set_motor_brake(int motor) __attribute__ ((deprecated));
-int rc_set_motor_brake_all() __attribute__ ((deprecated));
+int rc_set_motor_brake_all(void) __attribute__ ((deprecated));
 
 
 
diff --git a/library/include/rc/dsm.h b/library/include/rc/dsm.h
index 02d5c02b..217e5d73 100644
--- a/library/include/rc/dsm.h
+++ b/library/include/rc/dsm.h
@@ -39,7 +39,7 @@ extern "C" {
  *
  * @return     0 on success, -1 on failure
  */
-int rc_dsm_init();
+int rc_dsm_init(void);
 
 
 /**
@@ -48,7 +48,7 @@ int rc_dsm_init();
  * @return     0 on success, -1 on failure. 1 if there was a timeout due to user
  * callback function not returning.
  */
-int rc_dsm_cleanup();
+int rc_dsm_cleanup(void);
 
 
 /**
@@ -94,7 +94,7 @@ double rc_dsm_ch_normalized(int ch);
  * @return     returns 1 if new data is ready to be read by the user. otherwise
  * returns 0
  */
-int rc_dsm_is_new_data();
+int rc_dsm_is_new_data(void);
 
 
 /**
@@ -122,7 +122,7 @@ void rc_dsm_set_disconnect_callback(void (*func)(void));
  * @return     returns 1 if packets are arriving in good health without
  * timeouts. returns 0 otherwise.
  */
-int rc_dsm_is_connection_active();
+int rc_dsm_is_connection_active(void);
 
 
 /**
@@ -131,7 +131,7 @@ int rc_dsm_is_connection_active();
  * @return     Returns the number of nanoseconds since the last dsm packet was
  * received. Return -1 on error or if no packet has ever been received.
  */
-int64_t rc_dsm_nanos_since_last_packet();
+int64_t rc_dsm_nanos_since_last_packet(void);
 
 
 /**
@@ -141,7 +141,7 @@ int64_t rc_dsm_nanos_since_last_packet();
  * @return     returns 10 or 11 indicating 10-bit or 11-bit resolution returns a
  * 0 if no packet has been received yet or -1 on error
  */
-int rc_dsm_resolution();
+int rc_dsm_resolution(void);
 
 
 /**
@@ -150,7 +150,7 @@ int rc_dsm_resolution();
  * @return     Returns number of channels being received, 0 if no packet has
  * been received yet or -1 on error.
  */
-int rc_dsm_channels();
+int rc_dsm_channels(void);
 
 
 /**
@@ -189,7 +189,7 @@ int rc_dsm_channels();
  *
  * @return     0 on success, -1 on failure
  */
-int rc_dsm_bind_routine();
+int rc_dsm_bind_routine(void);
 
 
 /**
@@ -202,7 +202,7 @@ int rc_dsm_bind_routine();
  *
  * @return     0 on success, -1 on failure
  */
-int rc_dsm_calibrate_routine();
+int rc_dsm_calibrate_routine(void);
 
 
 #ifdef __cplusplus
diff --git a/library/include/rc/encoder.h b/library/include/rc/encoder.h
index 1f04f354..434fa113 100644
--- a/library/include/rc/encoder.h
+++ b/library/include/rc/encoder.h
@@ -33,7 +33,7 @@ extern "C" {
  *
  * @return     0 on success or -1 on failure
  */
-int rc_encoder_init();
+int rc_encoder_init(void);
 
 /**
  * @brief      Stops the encoder counters and closes file descriptors. This is
@@ -42,7 +42,7 @@ int rc_encoder_init();
  *
  * @return     0 on success or -1 on failure.
  */
-int rc_encoder_cleanup();
+int rc_encoder_cleanup(void);
 
 /**
  * @brief      Reads the current position of an encoder channel.
diff --git a/library/include/rc/encoder_eqep.h b/library/include/rc/encoder_eqep.h
index 0b971b6d..fc6c19a5 100644
--- a/library/include/rc/encoder_eqep.h
+++ b/library/include/rc/encoder_eqep.h
@@ -34,7 +34,7 @@ extern "C" {
  *
  * @return     0 on success or -1 on failure
  */
-int rc_encoder_eqep_init();
+int rc_encoder_eqep_init(void);
 
 /**
  * @brief      Stops the eQEP encoder counters and closes file descriptors. This
@@ -43,7 +43,7 @@ int rc_encoder_eqep_init();
  *
  * @return     0 on success or -1 on failure.
  */
-int rc_encoder_eqep_cleanup();
+int rc_encoder_eqep_cleanup(void);
 
 /**
  * @brief      Reads the current position of an encoder channel.
diff --git a/library/include/rc/encoder_pru.h b/library/include/rc/encoder_pru.h
index 2734ca6e..9953373a 100644
--- a/library/include/rc/encoder_pru.h
+++ b/library/include/rc/encoder_pru.h
@@ -35,14 +35,14 @@ extern "C" {
  *
  * @return     0 on success or -1 on failure
  */
-int rc_encoder_pru_init();
+int rc_encoder_pru_init(void);
 
 /**
  * @brief      Stops the PRU encoder counter and closes file descriptors. This
  * is not strictly necessary but is recommended that the user calls this
  * function at the end of their program.
  */
-void rc_encoder_pru_cleanup();
+void rc_encoder_pru_cleanup(void);
 
 /**
  * @brief      Reads the current position of encoder channel 4.
@@ -53,7 +53,7 @@ void rc_encoder_pru_cleanup();
  * @return     The current position (signed 32-bit integer) or -1 and prints an
  * error message is there is a problem.
  */
-int rc_encoder_pru_read();
+int rc_encoder_pru_read(void);
 
 /**
  * @brief      Sets the current position of encoder channel 4. Usually for
diff --git a/library/include/rc/led.h b/library/include/rc/led.h
index 44e565ce..97d2b860 100644
--- a/library/include/rc/led.h
+++ b/library/include/rc/led.h
@@ -64,7 +64,7 @@ int rc_led_set(rc_led_t led, int value);
  * This does NOT turn off the LEDs, it is up to the user to leave the LEDs in
  * the desired state before closing.
  */
-void rc_led_cleanup();
+void rc_led_cleanup(void);
 
 
 /**
@@ -113,7 +113,7 @@ void rc_led_stop_blink(rc_led_t led);
  * rc_led_stop_blink from a separate thread or signal handler. This will cause
  * rc_led_blink to return 1 if blinking was stopped mid-way.
  */
-void rc_led_stop_blink_all();
+void rc_led_stop_blink_all(void);
 
 
 
diff --git a/library/include/rc/math/filter.h b/library/include/rc/math/filter.h
index be5c0949..fe6e274d 100644
--- a/library/include/rc/math/filter.h
+++ b/library/include/rc/math/filter.h
@@ -92,7 +92,7 @@ typedef struct rc_filter_t{
  *
  * @return     Empty zero-filled rc_filter_t struct
  */
-rc_filter_t rc_filter_empty();
+rc_filter_t rc_filter_empty(void);
 
 /**
  * @brief      Allocate memory for a discrete-time filter & populates it with
diff --git a/library/include/rc/math/kalman.h b/library/include/rc/math/kalman.h
index de587e89..cdf7af53 100644
--- a/library/include/rc/math/kalman.h
+++ b/library/include/rc/math/kalman.h
@@ -123,7 +123,7 @@ typedef struct rc_kalman_t {
  *
  * @return     Empty zero-filled rc_kalman_t struct
  */
-rc_kalman_t rc_kalman_empty();
+rc_kalman_t rc_kalman_empty(void);
 
 /**
  * @brief      Allocates memory for a Kalman filter of given dimensions
diff --git a/library/include/rc/math/matrix.h b/library/include/rc/math/matrix.h
index 36872a09..ef09a76f 100644
--- a/library/include/rc/math/matrix.h
+++ b/library/include/rc/math/matrix.h
@@ -49,7 +49,7 @@ typedef struct rc_matrix_t{
  *
  * @return     Returns an empty rc_matrix_t
  */
-rc_matrix_t rc_matrix_empty();
+rc_matrix_t rc_matrix_empty(void);
 
 /**
  * @brief      Allocates memory for matrix A to have size rows&cols.
diff --git a/library/include/rc/math/other.h b/library/include/rc/math/other.h
index 61ba2b90..fe323160 100644
--- a/library/include/rc/math/other.h
+++ b/library/include/rc/math/other.h
@@ -27,7 +27,7 @@ extern "C" {
  *
  * @return     random floating point number between -1 and 1
  */
-float rc_get_random_float();
+float rc_get_random_float(void);
 
 /**
  * @brief      Returns a random double-precision floating point number between
@@ -38,7 +38,7 @@ float rc_get_random_float();
  *
  * @return     random double-precision floating point number between -1 and 1
  */
-double rc_get_random_double();
+double rc_get_random_double(void);
 
 /**
  * @brief      Modifies val to be bounded between between min and max.
diff --git a/library/include/rc/math/ring_buffer.h b/library/include/rc/math/ring_buffer.h
index e9f4b7cd..ac403835 100644
--- a/library/include/rc/math/ring_buffer.h
+++ b/library/include/rc/math/ring_buffer.h
@@ -49,7 +49,7 @@ typedef struct rc_ringbuf_t {
  *
  * @return     empty and ready-to-allocate rc_ringbuf_t
  */
-rc_ringbuf_t rc_ringbuf_empty();
+rc_ringbuf_t rc_ringbuf_empty(void);
 
 /**
  * @brief      Allocates memory for a ring buffer and initializes an
diff --git a/library/include/rc/math/vector.h b/library/include/rc/math/vector.h
index f3ed86b3..1ba86dfe 100644
--- a/library/include/rc/math/vector.h
+++ b/library/include/rc/math/vector.h
@@ -58,7 +58,7 @@ typedef struct rc_vector_t{
  * @return     rc_vector_t with no allocated memory and the initialized flag set
  * to 0.
  */
-rc_vector_t rc_vector_empty();
+rc_vector_t rc_vector_empty(void);
 
 /**
  * @brief      Allocates memory for vector v to have specified length.
diff --git a/library/include/rc/mavlink_udp.h b/library/include/rc/mavlink_udp.h
index 97c5f084..6854591f 100644
--- a/library/include/rc/mavlink_udp.h
+++ b/library/include/rc/mavlink_udp.h
@@ -103,7 +103,7 @@ int rc_mav_set_system_id(uint8_t system_id);
  *
  * @return     0 on success, -1 on failure
  */
-int rc_mav_cleanup();
+int rc_mav_cleanup(void);
 
 
 /**
@@ -201,7 +201,7 @@ int rc_mav_set_callback_connection_lost(void (*func)(void));
  *
  * @return     Returns current connection state.
  */
-rc_mav_connection_state_t rc_mav_get_connection_state();
+rc_mav_connection_state_t rc_mav_get_connection_state(void);
 
 
 /**
@@ -222,7 +222,7 @@ uint8_t rc_mav_get_sys_id_of_last_msg(int msg_id);
  * @return     Returns the system ID on success. Returns -1 on failure, for
  * example if no message has been received.
  */
-uint8_t rc_mav_get_sys_id_of_last_msg_any();
+uint8_t rc_mav_get_sys_id_of_last_msg_any(void);
 
 /**
  * @brief      Fetches the number of nanoseconds since the last message of type
@@ -243,7 +243,7 @@ int64_t rc_mav_ns_since_last_msg(int msg_id);
  * @return     Returns the number of nanoseconds since any message has been
  * received. Returns -1 on failure, for example if no message has been received.
  */
-int64_t rc_mav_ns_since_last_msg_any();
+int64_t rc_mav_ns_since_last_msg_any(void);
 
 /**
  * @brief      Returns the msg_id of the last received packet.
@@ -251,7 +251,7 @@ int64_t rc_mav_ns_since_last_msg_any();
  * @return     Returns the msg_id of the last received packet. Returns -1 on
  * failure, for example if no message has been received.
  */
-int rc_mav_msg_id_of_last_msg();
+int rc_mav_msg_id_of_last_msg(void);
 
 /**
  * @brief      Prints to stdout a human-readable name for a message type.
diff --git a/library/include/rc/mavlink_udp_helpers.h b/library/include/rc/mavlink_udp_helpers.h
index 5d96da60..bba842f4 100644
--- a/library/include/rc/mavlink_udp_helpers.h
+++ b/library/include/rc/mavlink_udp_helpers.h
@@ -42,7 +42,7 @@ extern "C" {
  *
  * @return     0 on success or -1 on failure.
  */
-int rc_mav_send_heartbeat_abbreviated();
+int rc_mav_send_heartbeat_abbreviated(void);
 
 /**
  * @brief      Constructs and sends a heartbeat packet of type
diff --git a/library/include/rc/model.h b/library/include/rc/model.h
index d8c5e803..f64b1b07 100644
--- a/library/include/rc/model.h
+++ b/library/include/rc/model.h
@@ -70,7 +70,7 @@ typedef enum rc_model_category_t{
  *
  * @return     rc_model_t enum representation of model
  */
-rc_model_t rc_model();
+rc_model_t rc_model(void);
 
 
 /**
@@ -78,21 +78,21 @@ rc_model_t rc_model();
  *
  * @return     rc_model_category_t enum representation of categoy
  */
-rc_model_category_t rc_model_category();
+rc_model_category_t rc_model_category(void);
 
 
 /**
  * @brief      prints to the screen the human-readable version of the model name
  * with no trailing newline character.
  */
-void rc_model_print();
+void rc_model_print(void);
 
 
 /**
  * @brief      prints to the screen the human-readable version of the category
  * name with no trailing newline character.
  */
-void rc_model_category_print();
+void rc_model_category_print(void);
 
 
 #ifdef __cplusplus
diff --git a/library/include/rc/motor.h b/library/include/rc/motor.h
index ec0740d1..beab5de5 100644
--- a/library/include/rc/motor.h
+++ b/library/include/rc/motor.h
@@ -42,7 +42,7 @@ extern "C" {
  * @return     0 on success, -1 on failure which is usually due to lack of user
  * permissions to access the gpio and pwm systems.
  */
-int rc_motor_init();
+int rc_motor_init(void);
 
 
 /**
@@ -71,7 +71,7 @@ int rc_motor_init_freq(int pwm_frequency_hz);
  *
  * @return     0 on success, -1 on failure.
  */
-int rc_motor_cleanup();
+int rc_motor_cleanup(void);
 
 
 /**
diff --git a/library/include/rc/mpu.h b/library/include/rc/mpu.h
index fed76fba..cb891b6b 100644
--- a/library/include/rc/mpu.h
+++ b/library/include/rc/mpu.h
@@ -242,7 +242,7 @@ typedef struct rc_mpu_data_t{
  *
  * @return     Returns an rc_mpu_config_t struct with default settings.
  */
-rc_mpu_config_t rc_mpu_default_config();
+rc_mpu_config_t rc_mpu_default_config(void);
 
 /**
  * @brief      Resets a config struct to defaults.
@@ -262,7 +262,7 @@ int rc_mpu_set_config_to_default(rc_mpu_config_t* conf);
  *
  * @return     0 on success or -1 on failure.
  */
-int rc_mpu_power_off();
+int rc_mpu_power_off(void);
 ///@} end common functions
 
 
@@ -385,7 +385,7 @@ int rc_mpu_set_dmp_callback(void (*func)(void));
  * @return     Returns 0 once new data is available, 1 if the MPU is shutting
  * down due to rc_mpu_power_off, or -1 on error.
  */
-int rc_mpu_block_until_dmp_data();
+int rc_mpu_block_until_dmp_data(void);
 
 
 /**
@@ -394,7 +394,7 @@ int rc_mpu_block_until_dmp_data();
  * @return     nanoseconds since last interrupt, or -1 if no interrupt received
  * yet.
  */
-int64_t rc_mpu_nanos_since_last_dmp_interrupt();
+int64_t rc_mpu_nanos_since_last_dmp_interrupt(void);
 
 
 /**
@@ -413,7 +413,7 @@ int rc_mpu_set_tap_callback(void (*func)(int direction, int counter));
  * @return     Returns 0 once a tap is detected, 1 if the MPU is shutting down
  * due to rc_mpu_power_off(), or -1 on error.
  */
-int rc_mpu_block_until_tap();
+int rc_mpu_block_until_tap(void);
 
 
 /**
@@ -422,7 +422,7 @@ int rc_mpu_block_until_tap();
  * @return     nanoseconds since last tap, or -1 if no tap has been detected
  * yet.
  */
-int64_t rc_mpu_nanos_since_last_tap();
+int64_t rc_mpu_nanos_since_last_tap(void);
 ///@} end interrupt-driven DMP mode functions
 
 
@@ -481,7 +481,7 @@ int rc_mpu_calibrate_accel_routine(rc_mpu_config_t conf);
  *
  * @return     1 if calibrated, 0 if not
  */
-int rc_mpu_is_gyro_calibrated();
+int rc_mpu_is_gyro_calibrated(void);
 
 
 /**
@@ -493,7 +493,7 @@ int rc_mpu_is_gyro_calibrated();
  *
  * @return     1 if calibrated, 0 if not
  */
-int rc_mpu_is_mag_calibrated();
+int rc_mpu_is_mag_calibrated(void);
 
 
 /**
@@ -505,7 +505,7 @@ int rc_mpu_is_mag_calibrated();
  *
  * @return     1 if calibrated, 0 if not
  */
-int rc_mpu_is_accel_calibrated();
+int rc_mpu_is_accel_calibrated(void);
 
 
 
diff --git a/library/include/rc/pinmux.h b/library/include/rc/pinmux.h
index 2e10cee3..c92f6606 100644
--- a/library/include/rc/pinmux.h
+++ b/library/include/rc/pinmux.h
@@ -112,7 +112,7 @@ int rc_pinmux_set(int pin, rc_pinmux_mode_t mode);
  *
  * @return     0 on success, -1 on failure
  */
-int rc_pinmux_set_default();
+int rc_pinmux_set_default(void);
 
 
 #ifdef __cplusplus
diff --git a/library/include/rc/pru.h b/library/include/rc/pru.h
index 24be9f8c..f974b16b 100644
--- a/library/include/rc/pru.h
+++ b/library/include/rc/pru.h
@@ -44,7 +44,7 @@ int rc_pru_start(int ch, const char* fw_name);
  *
  * @return     memory pointer on success, NULL on failure
  */
-volatile uint32_t* rc_pru_shared_mem_ptr();
+volatile uint32_t* rc_pru_shared_mem_ptr(void);
 
 
 /**
diff --git a/library/include/rc/pthread.h b/library/include/rc/pthread.h
index 003401d7..c46c65e4 100644
--- a/library/include/rc/pthread.h
+++ b/library/include/rc/pthread.h
@@ -90,7 +90,7 @@ int rc_pthread_set_properties_self(int policy, int priority);
  *
  * @return     niceness (-20 to 20) or -1 on failure and sets errno
  */
-int rc_pthread_get_process_niceness();
+int rc_pthread_get_process_niceness(void);
 
 
 /**
diff --git a/library/include/rc/servo.h b/library/include/rc/servo.h
index 2dc77574..87adf510 100644
--- a/library/include/rc/servo.h
+++ b/library/include/rc/servo.h
@@ -108,14 +108,14 @@ extern "C" {
  *
  * @return     0 on success, -1 on failure
  */
-int rc_servo_init();
+int rc_servo_init(void);
 
 /**
  * @brief      Cleans up servo functionality and turns off the power rail.
  *
  * @return     0 on success, -1 on failure
  */
-void rc_servo_cleanup();
+void rc_servo_cleanup(void);
 
 /**
  * @brief      enables or disables the 6V power rail to drive servos.
diff --git a/library/include/rc/start_stop.h b/library/include/rc/start_stop.h
index d8b9744a..0f99ee36 100644
--- a/library/include/rc/start_stop.h
+++ b/library/include/rc/start_stop.h
@@ -71,7 +71,7 @@ typedef enum rc_state_t {
  *
  * @return     current process state
  */
-rc_state_t rc_get_state();
+rc_state_t rc_get_state(void);
 
 
 /**
@@ -90,7 +90,7 @@ void rc_set_state(rc_state_t new_state);
  *
  * @return     0 on success, -1 on failure
  */
-int rc_print_state();
+int rc_print_state(void);
 
 
 /**
@@ -102,7 +102,7 @@ int rc_print_state();
  * rc_kill_exising_process() to kill that process. Returns -1 if there is some
  * other problem writing to the file.
  */
-int rc_make_pid_file();
+int rc_make_pid_file(void);
 
 
 /**
@@ -136,7 +136,7 @@ int rc_kill_existing_process(float timeout_s);
  * @return     Returns 0 whether or not the file was actually there. Returns -1
  * if there was a file system error.
  */
-int rc_remove_pid_file();
+int rc_remove_pid_file(void);
 
 
 /**
@@ -157,7 +157,7 @@ int rc_remove_pid_file();
  *
  * @return     Returns 0 on success or -1 on error
  */
-int rc_enable_signal_handler();
+int rc_enable_signal_handler(void);
 
 
 /**
@@ -167,7 +167,7 @@ int rc_enable_signal_handler();
  *
  * @return     Returns 0 on success or -1 on error
  */
-int rc_disable_signal_handler();
+int rc_disable_signal_handler(void);
 
 
 #ifdef __cplusplus
diff --git a/library/include/rc/time.h b/library/include/rc/time.h
index 711b66fe..e7af964d 100644
--- a/library/include/rc/time.h
+++ b/library/include/rc/time.h
@@ -63,7 +63,7 @@ void rc_usleep(unsigned int us);
  *
  * @return     nanoseconds since epoch
  */
-uint64_t rc_nanos_since_epoch();
+uint64_t rc_nanos_since_epoch(void);
 
 
 /**
@@ -75,7 +75,7 @@ uint64_t rc_nanos_since_epoch();
  *
  * @return     nanoseconds since system boot
  */
-uint64_t rc_nanos_since_boot();
+uint64_t rc_nanos_since_boot(void);
 
 
 /**
@@ -90,7 +90,7 @@ uint64_t rc_nanos_since_boot();
  *
  * @return     nanoseconds of CPU time since thread started
  */
-uint64_t rc_nanos_thread_time();
+uint64_t rc_nanos_thread_time(void);
 
 
 /**
diff --git a/library/include/rc/version.h b/library/include/rc/version.h
index 6e8162eb..169e47c9 100644
--- a/library/include/rc/version.h
+++ b/library/include/rc/version.h
@@ -34,7 +34,7 @@ extern "C" {
  *
  * @return     integer representation of the library version
  */
-unsigned int rc_version();
+unsigned int rc_version(void);
 
 
 /**
@@ -42,14 +42,14 @@ unsigned int rc_version();
  *
  * @return     const char* string
  */
-const char* rc_version_string();
+const char* rc_version_string(void);
 
 
 /**
  * @brief      prints a string representation of the current library version to
  * stdout with no trailing newline character.
  */
-void rc_version_print();
+void rc_version_print(void);
 
 
 #ifdef __cplusplus
diff --git a/library/src/bmp/bmp.c b/library/src/bmp/bmp.c
index 5adeabe9..3043310b 100644
--- a/library/src/bmp/bmp.c
+++ b/library/src/bmp/bmp.c
@@ -156,7 +156,7 @@ int rc_bmp_init(rc_bmp_oversample_t oversample, rc_bmp_filter_t filter)
 
 
 
-int rc_bmp_power_off()
+int rc_bmp_power_off(void)
 {
 	// make sure the bus is not currently in use by another thread
 	// do not proceed to prevent interfering with that process
@@ -266,7 +266,7 @@ int rc_bmp_read(rc_bmp_data_t* data)
 }
 
 
-int rc_set_sea_level_pressure_pa(double pa)
+int rc_bmp_set_sea_level_pressure_pa(double pa)
 {
 	// sanity checks
 	if(rc_bmp280_init_flag==0){
diff --git a/library/src/button.c b/library/src/button.c
index abc441be..bc7ce3a5 100644
--- a/library/src/button.c
+++ b/library/src/button.c
@@ -58,9 +58,9 @@ static int shutdown_flag = 0;
 
 /**
  * poll a gpio edge with debounce check. When the button changes state spawn off
- * teh user-defined callback in its own thread.
+ * the user-defined callback in its own thread.
  */
-void* poll_thread_func(void* arg)
+static void* poll_thread_func(void* arg)
 {
 	int val, event, chip, pin, pol, debounce;
 	int press_expected_event, release_expected_event;
@@ -221,7 +221,7 @@ int rc_button_init(int chip, int pin, char polarity, int debounce_us)
 }
 
 
-void rc_button_cleanup()
+void rc_button_cleanup(void)
 {
 	int i,j, ret;
 	// signal threads to close
diff --git a/library/src/cpu.c b/library/src/cpu.c
index d78d854b..e167ef52 100644
--- a/library/src/cpu.c
+++ b/library/src/cpu.c
@@ -54,7 +54,7 @@ int rc_cpu_set_governor(rc_governor_t gov)
 }
 
 
-int rc_cpu_get_freq()
+int rc_cpu_get_freq(void)
 {
 	int freq;
 	FILE* fd = fopen(CURFREQ_PATH, "r");
@@ -73,7 +73,7 @@ int rc_cpu_get_freq()
 }
 
 
-int rc_cpu_print_freq()
+int rc_cpu_print_freq(void)
 {
 	int freq= rc_cpu_get_freq();
 	if(freq==-1) return -1;
diff --git a/library/src/deprecated.c b/library/src/deprecated.c
index a671dd06..b1fd45ba 100644
--- a/library/src/deprecated.c
+++ b/library/src/deprecated.c
@@ -10,7 +10,7 @@
 #include <rc/encoder_eqep.h>
 
 
-int rc_initialize()
+int rc_initialize(void)
 {
 	// initialize pause and mode buttons
 	if(rc_button_init(RC_BTN_PIN_PAUSE, RC_BTN_POLARITY_NORM_HIGH,
@@ -39,7 +39,7 @@ int rc_initialize()
 	return 0;
 }
 
-int rc_cleanup()
+int rc_cleanup(void)
 {
 	rc_button_cleanup();
 	rc_encoder_eqep_cleanup();
@@ -88,7 +88,7 @@ int rc_set_mode_released_func(void (*func)(void)){
 	return rc_button_set_callbacks(RC_BTN_PIN_MODE, mode_pressed_func, mode_released_func);
 }
 
-rc_button_state_t rc_get_pause_button()
+rc_button_state_t rc_get_pause_button(void)
 {
 	int ret = rc_button_get_state(RC_BTN_PIN_PAUSE);
 	if(ret == RC_BTN_STATE_PRESSED) return PRESSED;
@@ -96,7 +96,7 @@ rc_button_state_t rc_get_pause_button()
 	return -1;
 }
 
-rc_button_state_t rc_get_mode_button()
+rc_button_state_t rc_get_mode_button(void)
 {
 	int ret = rc_button_get_state(RC_BTN_PIN_MODE);
 	if(ret == RC_BTN_STATE_PRESSED) return PRESSED;
@@ -117,12 +117,12 @@ int rc_set_encoder_pos(int ch, int value)
 
 
 
-int rc_enable_motors()
+int rc_enable_motors(void)
 {
 	return rc_motor_standby(0);
 }
 
-int rc_disable_motors()
+int rc_disable_motors(void)
 {
 	return rc_motor_standby(1);
 }
@@ -142,7 +142,7 @@ int rc_set_motor_free_spin(int motor)
 	return rc_motor_free_spin(motor);
 }
 
-int rc_set_motor_free_spin_all()
+int rc_set_motor_free_spin_all(void)
 {
 	return rc_motor_free_spin(0);
 
@@ -154,7 +154,7 @@ int rc_set_motor_brake(int motor)
 
 }
 
-int rc_set_motor_brake_all()
+int rc_set_motor_brake_all(void)
 {
 	return rc_motor_brake(0);
 }
\ No newline at end of file
diff --git a/library/src/dsm.c b/library/src/dsm.c
index 98b2cfbe..c8b72b66 100644
--- a/library/src/dsm.c
+++ b/library/src/dsm.c
@@ -73,7 +73,8 @@ static int init_flag=0;
  *
  * @return     { description_of_the_return_value }
  */
-char* __byte_to_binary(unsigned char c)
+#ifdef DEBUG
+static char* __byte_to_binary(unsigned char c)
 {
 	static char b[9];
 	unsigned char x = (unsigned char)c; //cast to unsigned
@@ -85,6 +86,7 @@ char* __byte_to_binary(unsigned char c)
 	}
 	return b;
 }
+#endif
 
 /**
  * This is a blocking function which returns 1 if the user presses ENTER. it
@@ -94,7 +96,7 @@ char* __byte_to_binary(unsigned char c)
  *
  * @return     { description_of_the_return_value }
  */
-int __continue_or_quit()
+static int __continue_or_quit(void)
 {
 	// set stdin to non-canonical raw mode to capture all button presses
 	fflush(stdin);
@@ -133,7 +135,7 @@ int __continue_or_quit()
  *
  * @return     { description_of_the_return_value }
  */
-void* __parser_func(__attribute__ ((unused)) void* ptr){
+static void* __parser_func(__attribute__ ((unused)) void* ptr){
 	uint8_t buf[DSM_PACKET_SIZE];
 	int i, ret;
 	int new_values[RC_MAX_DSM_CHANNELS]; // hold new values before committing
@@ -188,7 +190,8 @@ void* __parser_func(__attribute__ ((unused)) void* ptr){
 			// last few words in buffer are often all 1's, ignore those
 			if((buf[2*i]!=0xFF) || (buf[(2*i)+1]!=0xFF)){
 				// grab channel id from first byte assuming 1024 mode
-				ch_id = (buf[i*2]&0b01111100)>>2;
+				// 0x7C is 0b01111100
+				ch_id = (buf[i*2]&0x7C)>>2;
 				if(ch_id>max_channel_id_1024){
 					max_channel_id_1024 = ch_id;
 				}
@@ -209,7 +212,8 @@ void* __parser_func(__attribute__ ((unused)) void* ptr){
 			// last few words in buffer are often all 1's, ignore those
 			if((buf[2*i]!=0xFF) || (buf[(2*i)+1]!=0xFF)){
 				// now grab assuming 2048 mode
-				ch_id = (buf[i*2]&0b01111000)>>3;
+				// 0x78 is 0b01111000
+				ch_id = (buf[i*2]&0x78)>>3;
 				if(ch_id>max_channel_id_2048){
 					 max_channel_id_2048 = ch_id;
 				}
@@ -338,15 +342,18 @@ void* __parser_func(__attribute__ ((unused)) void* ptr){
 				// grab channel id from first byte
 				// and value from both bytes
 				if(resolution == 1024){
-					ch_id = (buf[i*2]&0b01111100)>>2;
+					// 0x7c is 0b01111100
+					ch_id = (buf[i*2]&0x7C)>>2;
 					// grab value from least 11 bytes
-					value = ((buf[i*2]&0b00000011)<<8) + buf[(2*i)+1];
+					value = ((buf[i*2]&0x03)<<8) + buf[(2*i)+1];
 					value += 989; // shift range so 1500 is neutral
 				}
 				else if(resolution == 2048){
-					ch_id = (buf[i*2]&0b01111000)>>3;
+					// 0x78 is 0b01111000
+					ch_id = (buf[i*2]&0x78)>>3;
 					// grab value from least 11 bytes
-					value = ((buf[i*2]&0b00000111)<<8) + buf[(2*i)+1];
+					// 0x07 is 0b00000111
+					value = ((buf[i*2]&0x07)<<8) + buf[(2*i)+1];
 					// extra bit of precision means scale is off by factor of
 					// two, also add 989 to center channels around 1500
 					value = (value/2) + 989;
@@ -424,7 +431,7 @@ void* __parser_func(__attribute__ ((unused)) void* ptr){
  *
  * @return     NULL
  */
-void* __calibration_listen_func(__attribute__ ((unused)) void *ptr)
+static void* __calibration_listen_func(__attribute__ ((unused)) void *ptr)
 {
 	int j, raw;
 	//wait for data to start
@@ -475,7 +482,7 @@ void* __calibration_listen_func(__attribute__ ((unused)) void *ptr)
 }
 
 
-int rc_dsm_init()
+int rc_dsm_init(void)
 {
 	int i;
 	//if calibration file exists, load it and start spektrum thread
@@ -572,7 +579,7 @@ int rc_dsm_init()
 }
 
 
-int rc_dsm_cleanup()
+int rc_dsm_cleanup(void)
 {
 	int ret;
 	// just return if not running
@@ -633,7 +640,7 @@ double rc_dsm_ch_normalized(int ch)
 }
 
 
-int rc_dsm_is_new_data()
+int rc_dsm_is_new_data(void)
 {
 	if(init_flag==0){
 		fprintf(stderr,"ERROR in rc_dsm_is_new_data, call rc_dsm_init first\n");
@@ -662,7 +669,7 @@ void rc_dsm_set_disconnect_callback(void (*func)(void))
 }
 
 
-int rc_dsm_is_connection_active()
+int rc_dsm_is_connection_active(void)
 {
 	if(init_flag==0){
 		fprintf(stderr,"ERROR in rc_dsm_is_connection_active, call rc_dsm_init first\n");
@@ -672,7 +679,7 @@ int rc_dsm_is_connection_active()
 }
 
 
-int64_t rc_dsm_nanos_since_last_packet(){
+int64_t rc_dsm_nanos_since_last_packet(void){
 	if(init_flag==0){
 		fprintf(stderr,"ERROR in rc_dsm_nanos_since_last_packet, call rc_dsm_init first\n");
 		return -1;
@@ -683,7 +690,7 @@ int64_t rc_dsm_nanos_since_last_packet(){
 }
 
 
-int rc_dsm_resolution()
+int rc_dsm_resolution(void)
 {
 	if(init_flag==0){
 		fprintf(stderr,"ERROR in rc_dsm_resolution, call rc_dsm_init first\n");
@@ -693,7 +700,7 @@ int rc_dsm_resolution()
 }
 
 
-int rc_dsm_channels()
+int rc_dsm_channels(void)
 {
 	if(init_flag==0){
 		fprintf(stderr,"ERROR in rc_dsm_channels, call rc_dsm_init first\n");
@@ -706,7 +713,7 @@ int rc_dsm_channels()
 
 
 
-int rc_dsm_bind_routine()
+int rc_dsm_bind_routine(void)
 {
 	int value, delay, i;
 	char c = 0; // for reading user input
@@ -842,7 +849,7 @@ int rc_dsm_bind_routine()
 }
 
 
-int rc_dsm_calibrate_routine()
+int rc_dsm_calibrate_routine(void)
 {
 	int i,ret;
 	FILE* fd;
diff --git a/library/src/encoder.c b/library/src/encoder.c
index 6ce71b34..a73b7a9b 100644
--- a/library/src/encoder.c
+++ b/library/src/encoder.c
@@ -3,11 +3,12 @@
  */
 
 #include <stdio.h>
+#include <rc/encoder.h>
 #include <rc/encoder_pru.h>
 #include <rc/encoder_eqep.h>
 
 
-int rc_encoder_init()
+int rc_encoder_init(void)
 {
 	if(rc_encoder_eqep_init()){
 		fprintf(stderr,"ERROR: failed to run rc_encoder_eqep_init\n");
@@ -20,7 +21,7 @@ int rc_encoder_init()
 	return 0;
 }
 
-int rc_encoder_cleanup()
+int rc_encoder_cleanup(void)
 {
 	rc_encoder_eqep_cleanup();
 	rc_encoder_pru_cleanup();
diff --git a/library/src/io/adc.c b/library/src/io/adc.c
index c21bc776..67e2006e 100644
--- a/library/src/io/adc.c
+++ b/library/src/io/adc.c
@@ -35,7 +35,7 @@ static int init_flag = 0; // boolean to check if mem mapped
 static int fd[CHANNELS]; // file descriptors for 8 channels
 
 
-int rc_adc_init()
+int rc_adc_init(void)
 {
 	char buf[MAX_BUF];
 	int i, temp_fd;
@@ -55,7 +55,7 @@ int rc_adc_init()
 	return 0;
 }
 
-int rc_adc_cleanup()
+int rc_adc_cleanup(void)
 {
 	int i;
 	for(i=0;i<CHANNELS;i++){
@@ -104,7 +104,7 @@ double rc_adc_read_volt(int ch)
 }
 
 
-double rc_adc_batt()
+double rc_adc_batt(void)
 {
 	double v = (rc_adc_read_volt(LIPO_ADC_CH)*V_DIV_RATIO)+LIPO_OFFSET;
 	// add in a little dead zone to make disconnected battery easier to detect
@@ -113,7 +113,7 @@ double rc_adc_batt()
 }
 
 
-double rc_adc_dc_jack()
+double rc_adc_dc_jack(void)
 {
 	double v = (rc_adc_read_volt(DC_JACK_ADC_CH)*V_DIV_RATIO)+DC_JACK_OFFSET;
 	if(v<BATT_DEADZONE) v = 0.0;
diff --git a/library/src/io/encoder_eqep.c b/library/src/io/encoder_eqep.c
index 0aeb38c8..52894a6a 100644
--- a/library/src/io/encoder_eqep.c
+++ b/library/src/io/encoder_eqep.c
@@ -29,7 +29,7 @@ static int init_flag = 0; // boolean to check if mem mapped
 
 
 
-int rc_encoder_eqep_init()
+int rc_encoder_eqep_init(void)
 {
 	int temp_fd;
 	if(init_flag) return 0;
@@ -113,7 +113,7 @@ int rc_encoder_eqep_init()
 	return 0;
 }
 
-int rc_encoder_eqep_cleanup()
+int rc_encoder_eqep_cleanup(void)
 {
 	int i;
 	for(i=0;i<3;i++){
diff --git a/library/src/io/i2c.c b/library/src/io/i2c.c
index cdde035c..c69185de 100644
--- a/library/src/io/i2c.c
+++ b/library/src/io/i2c.c
@@ -35,7 +35,7 @@ static rc_i2c_state_t i2c[I2C_MAX_BUS+1];
 
 
 // local function
-int __check_bus_range(int bus)
+static int __check_bus_range(int bus)
 {
 	if(unlikely(bus<0 || bus>I2C_MAX_BUS)){
 		fprintf(stderr,"ERROR: i2c bus must be between 0 & %d\n", I2C_MAX_BUS);
@@ -428,7 +428,9 @@ int rc_i2c_get_fd(int bus) {
 }
 
 
+#ifdef RC_AUTOPILOT_EXT
 int rc_i2c_read_data(int bus, uint8_t regAddr, size_t length, uint8_t *data)
 {
 	return rc_i2c_read_bytes(bus, regAddr, length, data);
-}
\ No newline at end of file
+}
+#endif // RC_AUTOPILOT_EXT
\ No newline at end of file
diff --git a/library/src/io/pwm.c b/library/src/io/pwm.c
index 484993e6..926ba5ce 100644
--- a/library/src/io/pwm.c
+++ b/library/src/io/pwm.c
@@ -53,7 +53,7 @@ static int ssindex[3]; // index given by the kernel to each pwm chip when in mod
  *
  * @return     0 on succcess, -1 on failure
  */
-int __export_channels(int ss)
+static int __export_channels(int ss)
 {
 	int export_fd=0;
 	char buf[MAXBUF];
@@ -142,7 +142,7 @@ int __export_channels(int ss)
  *
  * @return     0 on succcess, -1 on failure
  */
-int __unexport_channels(int ss)
+static int __unexport_channels(int ss)
 {
 	int unexport_fd=0;
 	char buf[MAXBUF];
diff --git a/library/src/led.c b/library/src/led.c
index e6a36209..e9cfad74 100644
--- a/library/src/led.c
+++ b/library/src/led.c
@@ -80,7 +80,7 @@ int rc_led_set(rc_led_t led, int value)
 	return 0;
 }
 
-void rc_led_cleanup()
+void rc_led_cleanup(void)
 {
 	int i;
 	for(i=0;i<NUM_LEDS;i++) close(fd[i]);
@@ -157,7 +157,7 @@ void rc_led_stop_blink(rc_led_t led)
 }
 
 
-void rc_led_stop_blink_all()
+void rc_led_stop_blink_all(void)
 {
 	int i;
 	for(i=0;i<NUM_LEDS;i++) stop_blinking_flag[i]=0;
diff --git a/library/src/math/algebra.c b/library/src/math/algebra.c
index ed991080..d3a86524 100644
--- a/library/src/math/algebra.c
+++ b/library/src/math/algebra.c
@@ -27,7 +27,7 @@ double zero_tolerance=DEFAULT_ZERO_TOLERANCE;
 
 
 // used by QR decomposition
-int __householder_reflection(int step, rc_matrix_t* Q, rc_matrix_t* R)
+static int __householder_reflection(int step, rc_matrix_t* Q, rc_matrix_t* R)
 {
 	int i,j,k;
 	double norm, tau, taui, dot;
diff --git a/library/src/math/algebra_common.c b/library/src/math/algebra_common.c
index a3eac8fa..a5da54cf 100644
--- a/library/src/math/algebra_common.c
+++ b/library/src/math/algebra_common.c
@@ -4,6 +4,7 @@
  * see algebra_common.h
  **/
 
+#include "algebra_common.h"
 
 double __vectorized_mult_accumulate(double * __restrict__ a, double * __restrict__ b, int n)
 {
diff --git a/library/src/math/filter.c b/library/src/math/filter.c
index 1c3ad01e..f793c268 100644
--- a/library/src/math/filter.c
+++ b/library/src/math/filter.c
@@ -37,7 +37,7 @@ static int print_poly_z(rc_vector_t v)
 }
 
 
-rc_filter_t rc_filter_empty()
+rc_filter_t rc_filter_empty(void)
 {
 	rc_filter_t f;
 	f.order		= 0;
diff --git a/library/src/math/kalman.c b/library/src/math/kalman.c
index ea642277..6206410a 100644
--- a/library/src/math/kalman.c
+++ b/library/src/math/kalman.c
@@ -11,7 +11,7 @@
 #include <rc/math/kalman.h>
 #include "algebra_common.h"
 
-rc_kalman_t rc_kalman_empty()
+rc_kalman_t rc_kalman_empty(void)
 {
 	rc_kalman_t kf;
 	// set struct to zeros
diff --git a/library/src/math/matrix.c b/library/src/math/matrix.c
index 9a76464c..52bb4a08 100644
--- a/library/src/math/matrix.c
+++ b/library/src/math/matrix.c
@@ -64,7 +64,7 @@ int rc_matrix_alloc(rc_matrix_t* A, int rows, int cols)
 		return -1;
 	}
 	// manually fill in the pointer to each row
-	for(i=0;i<rows;i++) A->d[i]=(double*)(ptr+i*cols*sizeof(double));
+	for(i=0;i<rows;i++) A->d[i]=(double*)(((char*)ptr) + (i*cols*sizeof(double)));
 	A->rows = rows;
 	A->cols = cols;
 	A->initialized = 1;
@@ -115,7 +115,7 @@ int rc_matrix_zeros(rc_matrix_t* A, int rows, int cols)
 		return -1;
 	}
 	// manually fill in the pointer to each row
-	for(i=0;i<rows;i++) A->d[i]=(double*)(ptr+i*cols*sizeof(double));
+	for(i=0;i<rows;i++) A->d[i]=(double*)(((char*)ptr) + (i*cols*sizeof(double)));
 	A->rows = rows;
 	A->cols = cols;
 	A->initialized = 1;
diff --git a/library/src/math/other.c b/library/src/math/other.c
index f8b872c8..5c98913f 100644
--- a/library/src/math/other.c
+++ b/library/src/math/other.c
@@ -22,7 +22,7 @@ typedef union {
 	float f;
 }rc_int_float_t;
 
-float rc_get_random_float()
+float rc_get_random_float(void)
 {
 	rc_int_float_t new;
 	// get random 32-bit int, mask out all but the mantissa (right 23 bits)
@@ -37,7 +37,7 @@ typedef union {
 	double d;
 }rc_int_double_t;
 
-double rc_get_random_double()
+double rc_get_random_double(void)
 {
 	rc_int_double_t new;
 	// get random 64-bit int, mask out all but the mantissa (right 52 bits)
diff --git a/library/src/math/ring_buffer.c b/library/src/math/ring_buffer.c
index e53c23eb..434a6d52 100644
--- a/library/src/math/ring_buffer.c
+++ b/library/src/math/ring_buffer.c
@@ -27,7 +27,7 @@
 
 
 
-rc_ringbuf_t rc_ringbuf_empty()
+rc_ringbuf_t rc_ringbuf_empty(void)
 {
 	rc_ringbuf_t out;
 	// zero-out piecemeal instead of with memset to avoid issues with padding
diff --git a/library/src/math/vector.c b/library/src/math/vector.c
index aabddf50..c579062f 100644
--- a/library/src/math/vector.c
+++ b/library/src/math/vector.c
@@ -67,7 +67,7 @@ int rc_vector_free(rc_vector_t* v)
 }
 
 
-rc_vector_t rc_vector_empty()
+rc_vector_t rc_vector_empty(void)
 {
 	rc_vector_t out;
 	out.d = NULL;
diff --git a/library/src/mavlink_udp.c b/library/src/mavlink_udp.c
index b78a21e4..3edefd3b 100644
--- a/library/src/mavlink_udp.c
+++ b/library/src/mavlink_udp.c
@@ -68,7 +68,6 @@ static int listening_flag=0;
 
 // private local function declarations;
 static uint64_t __us_since_boot();
-static void* __listen_thread_func();
 static int __address_init(struct sockaddr_in* address, const char* dest_ip, uint16_t port);
 int __get_msg_common_checks(int msg_id);
 
@@ -83,7 +82,7 @@ static uint64_t __us_since_boot()
 }
 
 // background thread for handling packets
-void* __listen_thread_func()
+static void* __listen_thread_func(__attribute__((unused)) void* ptr)
 {
 	int i;
 	uint64_t time;
@@ -287,7 +286,7 @@ int rc_mav_set_system_id(uint8_t sys_id)
 }
 
 
-int rc_mav_cleanup()
+int rc_mav_cleanup(void)
 {
 	int ret = 0;
 	if(init_flag==0 || listening_flag==0){
@@ -416,7 +415,7 @@ uint8_t rc_mav_get_sys_id_of_last_msg(int msg_id)
 	return messages[msg_id].sysid;
 }
 
-uint8_t rc_mav_get_sys_id_of_last_msg_any()
+uint8_t rc_mav_get_sys_id_of_last_msg_any(void)
 {
 	if(init_flag==0){
 		fprintf(stderr, "ERROR in rc_mav_get_sys_id_of_last_msg_any, call rc_mav_init first\n");
@@ -441,7 +440,7 @@ int64_t rc_mav_ns_since_last_msg(int msg_id)
 	return __us_since_boot()-us_of_last_msg[msg_id];
 }
 
-int64_t rc_mav_ns_since_last_msg_any()
+int64_t rc_mav_ns_since_last_msg_any(void)
 {
 	if(init_flag==0){
 		fprintf(stderr, "ERROR in rc_mav_ns_since_last_msg_any, call rc_mav_init first\n");
@@ -453,7 +452,7 @@ int64_t rc_mav_ns_since_last_msg_any()
 	return __us_since_boot()-us_of_last_msg_any;
 }
 
-int rc_mav_msg_id_of_last_msg()
+int rc_mav_msg_id_of_last_msg(void)
 {
 	if(init_flag==0){
 		fprintf(stderr, "ERROR in rc_mav_msg_id_of_last_msg, call rc_mav_init first\n");
@@ -465,7 +464,7 @@ int rc_mav_msg_id_of_last_msg()
 
 
 
-int rc_mav_send_heartbeat_abbreviated()
+int rc_mav_send_heartbeat_abbreviated(void)
 {
 	// sanity check
 	mavlink_message_t msg;
diff --git a/library/src/model.c b/library/src/model.c
index ca9ee5bb..0ddcd55d 100644
--- a/library/src/model.c
+++ b/library/src/model.c
@@ -23,7 +23,7 @@ static int has_checked = 0;
 
 
 
-static void __check_model()
+static void __check_model(void)
 {
 	char c[BUF_SIZE];
 	int ret;
@@ -150,7 +150,7 @@ static void __check_model()
 }
 
 
-rc_model_t rc_model()
+rc_model_t rc_model(void)
 {
 	if(has_checked) return current_model;
 
@@ -159,7 +159,7 @@ rc_model_t rc_model()
 	return current_model;
 }
 
-rc_model_category_t rc_model_category()
+rc_model_category_t rc_model_category(void)
 {
 	if(has_checked) return current_category;
 
@@ -171,7 +171,7 @@ rc_model_category_t rc_model_category()
 
 #define caseprint(X) case(X): printf(#X); break;
 
-void rc_model_print()
+void rc_model_print(void)
 {
 	rc_model_t model = rc_model();
 
@@ -203,7 +203,7 @@ void rc_model_print()
 	return;
 }
 
-void rc_model_category_print()
+void rc_model_category_print(void)
 {
 	rc_model_category_t category = rc_model_category();
 
diff --git a/library/src/motor.c b/library/src/motor.c
index b2b4f0b7..cf30b0d4 100644
--- a/library/src/motor.c
+++ b/library/src/motor.c
@@ -58,7 +58,7 @@ static int pwmch[CHANNELS];
 
 
 
-int rc_motor_init()
+int rc_motor_init(void)
 {
 	return rc_motor_init_freq(RC_MOTOR_DEFAULT_PWM_FREQ);
 }
@@ -160,7 +160,7 @@ int rc_motor_init_freq(int pwm_frequency_hz)
 
 
 
-int rc_motor_cleanup()
+int rc_motor_cleanup(void)
 {
 	int i;
 	if(!init_flag) return 0;
diff --git a/library/src/mpu/mpu.c b/library/src/mpu/mpu.c
index 630c2f96..18c15d67 100644
--- a/library/src/mpu/mpu.c
+++ b/library/src/mpu/mpu.c
@@ -108,22 +108,31 @@ static double startMagYaw = 0.0;
 /**
 * functions for internal use only
 **/
-static int __reset_mpu();
-static int __check_who_am_i();
+static int __reset_mpu(void);
+static int __check_who_am_i(void);
 static int __set_gyro_fsr(rc_mpu_gyro_fsr_t fsr, rc_mpu_data_t* data);
 static int __set_accel_fsr(rc_mpu_accel_fsr_t, rc_mpu_data_t* data);
 static int __set_gyro_dlpf(rc_mpu_gyro_dlpf_t dlpf);
 static int __set_accel_dlpf(rc_mpu_accel_dlpf_t dlpf);
 static int __init_magnetometer(int cal_mode);
-static int __power_off_magnetometer();
+static int __power_off_magnetometer(void);
 static int __mpu_set_bypass(unsigned char bypass_on);
 static int __mpu_write_mem(unsigned short mem_addr, unsigned short length, unsigned char *data);
 static int __mpu_read_mem(unsigned short mem_addr, unsigned short length, unsigned char *data);
-static int __dmp_load_motion_driver_firmware();
+static int __dmp_load_motion_driver_firmware(void);
 static int __dmp_set_orientation(unsigned short orient);
 static int __dmp_enable_gyro_cal(unsigned char enable);
 static int __dmp_enable_lp_quat(unsigned char enable);
 static int __dmp_enable_6x_lp_quat(unsigned char enable);
+static int __dmp_set_tap_thresh(unsigned char axis, unsigned short thresh);
+static int __dmp_set_tap_axes(unsigned char axis);
+static int __dmp_set_tap_count(unsigned char min_taps);
+static int __dmp_set_tap_time(unsigned short time);
+static int __dmp_set_tap_time_multi(unsigned short time);
+static int __dmp_set_shake_reject_thresh(long sf, unsigned short thresh);
+static int __dmp_set_shake_reject_time(unsigned short time);
+static int __dmp_set_shake_reject_timeout(unsigned short time);
+static int __collect_accel_samples(int* avg_raw);
 static int __mpu_reset_fifo(void);
 static int __mpu_set_sample_rate(int rate);
 static int __dmp_set_fifo_rate(unsigned short rate);
@@ -131,9 +140,9 @@ static int __dmp_enable_feature(unsigned short mask);
 static int __mpu_set_dmp_state(unsigned char enable);
 static int __set_int_enable(unsigned char enable);
 static int __dmp_set_interrupt_mode(unsigned char mode);
-static int __load_gyro_calibration();
-static int __load_mag_calibration();
-static int __load_accel_calibration();
+static int __load_gyro_calibration(void);
+static int __load_mag_calibration(void);
+static int __load_accel_calibration(void);
 static int __write_gyro_cal_to_disk(int16_t offsets[3]);
 static int __write_mag_cal_to_disk(double offsets[3], double scale[3]);
 static int __write_accel_cal_to_disk(double* center, double* lengths);
@@ -143,7 +152,7 @@ static int __data_fusion(rc_mpu_data_t* data);
 static int __mag_correct_orientation(double mag_vec[3]);
 
 
-rc_mpu_config_t rc_mpu_default_config()
+rc_mpu_config_t rc_mpu_default_config(void)
 {
 	rc_mpu_config_t conf;
 
@@ -408,7 +417,7 @@ int rc_mpu_read_temp(rc_mpu_data_t* data)
 }
 
 
-int __reset_mpu()
+int __reset_mpu(void)
 {
 	// disable the interrupt to prevent it from doing things while we reset
 	imu_shutdown_flag = 1;
@@ -431,7 +440,8 @@ int __reset_mpu()
 }
 
 
-int __check_who_am_i(){
+int __check_who_am_i(void)
+{
 	uint8_t c;
 	//check the who am i register to make sure the chip is alive
 	if(rc_i2c_read_byte(config.i2c_bus, WHO_AM_I_MPU9250, &c)<0){
@@ -641,7 +651,7 @@ int __init_magnetometer(int cal_mode)
 }
 
 
-int __power_off_magnetometer()
+int __power_off_magnetometer(void)
 {
 	rc_i2c_set_device_address(config.i2c_bus, config.i2c_addr);
 	// Enable i2c bypass to allow talking to magnetometer
@@ -662,7 +672,7 @@ int __power_off_magnetometer()
 }
 
 
-int rc_mpu_power_off()
+int rc_mpu_power_off(void)
 {
 	imu_shutdown_flag = 1;
 	// wait for the interrupt thread to exit if it hasn't already
@@ -1028,7 +1038,7 @@ int __mpu_read_mem(unsigned short mem_addr, unsigned short length, unsigned char
 *
 * loads pre-compiled firmware binary from invensense onto dmp
 **/
-int __dmp_load_motion_driver_firmware()
+int __dmp_load_motion_driver_firmware(void)
 {
 	unsigned short ii;
 	unsigned short this_write;
@@ -2227,7 +2237,7 @@ int __data_fusion(rc_mpu_data_t* data)
  *
  * @return     0 on success, -1 on failure
  */
-int __load_gyro_calibration()
+int __load_gyro_calibration(void)
 {
 	FILE* fd;
 	uint8_t data[6];
@@ -2286,7 +2296,7 @@ int __load_gyro_calibration()
  *
  * @return     0 on success, -1 on failure
  */
-int __load_mag_calibration()
+int __load_mag_calibration(void)
 {
 	FILE *fd;
 	double x,y,z,sx,sy,sz;
@@ -2339,7 +2349,7 @@ int __load_mag_calibration()
  *
  * @return     0 on success, -1 on failure
  */
-int __load_accel_calibration()
+int __load_accel_calibration(void)
 {
 	FILE* fd;
 	uint8_t raw[6] = {0,0,0,0,0,0};
@@ -3216,139 +3226,39 @@ int rc_mpu_calibrate_accel_routine(rc_mpu_config_t conf)
 }
 
 
-int rc_mpu_is_gyro_calibrated()
+int rc_mpu_is_gyro_calibrated(void)
 {
 	if(!access(CALIBRATION_DIR GYRO_CAL_FILE, F_OK)) return 1;
 	else return 0;
 }
 
-int rc_mpu_is_mag_calibrated()
+int rc_mpu_is_mag_calibrated(void)
 {
 	if(!access(CALIBRATION_DIR MAG_CAL_FILE, F_OK)) return 1;
 	else return 0;
 }
 
-int rc_mpu_is_accel_calibrated()
+int rc_mpu_is_accel_calibrated(void)
 {
 	if(!access(CALIBRATION_DIR ACCEL_CAL_FILE, F_OK)) return 1;
 	else return 0;
 }
 
 
-/**
- * takes a single row on a rotation matrix and returns the associated scalar for
- * use by __inv_orientation_matrix_to_scalar.
- *
- * @param      row   The row
- *
- * @return     { description_of_the_return_value }
- */
-unsigned short __inv_row_2_scale(signed char row[])
-{
-	unsigned short b;
-
-	if (row[0] > 0)
-		b = 0;
-	else if (row[0] < 0)
-		b = 4;
-	else if (row[1] > 0)
-		b = 1;
-	else if (row[1] < 0)
-		b = 5;
-	else if (row[2] > 0)
-		b = 2;
-	else if (row[2] < 0)
-		b = 6;
-	else
-		b = 7;      // error
-	return b;
-}
-
-/**
- * This take in a rotation matrix and returns the corresponding 16 bit short
- * which is sent to the DMP to set the orientation. This function is actually
- * not used in normal operation and only served to retrieve the orientation
- * scalars once to populate the rc_mpu_orientation_t enum during development.
- *
- * @param      mtx   The mtx
- *
- * @return     { description_of_the_return_value }
- */
-unsigned short __inv_orientation_matrix_to_scalar(signed char mtx[])
-{
-	unsigned short scalar;
-
-	scalar = __inv_row_2_scale(mtx);
-	scalar |= __inv_row_2_scale(mtx + 3) << 3;
-	scalar |= __inv_row_2_scale(mtx + 6) << 6;
-	return scalar;
-}
-
-/**
- * this function purely serves to print out orientation values and rotation
- * matrices which form the rc_imu_orientation_t enum. This is not called inside
- * this C file and is not exposed to the user.
- */
-void __print_orientation_info()
-{
-	printf("\n");
-	//char mtx[9];
-	unsigned short orient;
-
-	// Z-UP (identity matrix)
-	signed char zup[] = {1,0,0, 0,1,0, 0,0,1};
-	orient = __inv_orientation_matrix_to_scalar(zup);
-	printf("Z-UP: %d\n", orient);
-
-	// Z-down
-	signed char zdown[] = {-1,0,0, 0,1,0, 0,0,-1};
-	orient = __inv_orientation_matrix_to_scalar(zdown);
-	printf("Z-down: %d\n", orient);
-
-	// X-up
-	signed char xup[] = {0,0,-1, 0,1,0, 1,0,0};
-	orient = __inv_orientation_matrix_to_scalar(xup);
-	printf("x-up: %d\n", orient);
-
-	// X-down
-	signed char xdown[] = {0,0,1, 0,1,0, -1,0,0};
-	orient = __inv_orientation_matrix_to_scalar(xdown);
-	printf("x-down: %d\n", orient);
-
-	// Y-up
-	signed char yup[] = {1,0,0, 0,0,-1, 0,1,0};
-	orient = __inv_orientation_matrix_to_scalar(yup);
-	printf("y-up: %d\n", orient);
-
-	// Y-down
-	signed char ydown[] = {1,0,0, 0,0,1, 0,-1,0};
-	orient = __inv_orientation_matrix_to_scalar(ydown);
-	printf("y-down: %d\n", orient);
-
-	// X-forward
-	signed char xforward[] = {0,-1,0, 1,0,0, 0,0,1};
-	orient = __inv_orientation_matrix_to_scalar(xforward);
-	printf("x-forward: %d\n", orient);
-
-	// X-back
-	signed char xback[] = {0,1,0, -1,0,0, 0,0,1};
-	orient = __inv_orientation_matrix_to_scalar(xback);
-	printf("yx-back: %d\n", orient);
-}
 
-int64_t rc_mpu_nanos_since_last_dmp_interrupt()
+int64_t rc_mpu_nanos_since_last_dmp_interrupt(void)
 {
 	if(last_interrupt_timestamp_nanos==0) return -1;
 	return rc_nanos_since_epoch() - last_interrupt_timestamp_nanos;
 }
 
-int64_t rc_mpu_nanos_since_last_tap()
+int64_t rc_mpu_nanos_since_last_tap(void)
 {
 	if(last_tap_timestamp_nanos==0) return -1;
 	return rc_nanos_since_epoch() - last_tap_timestamp_nanos;
 }
 
-int rc_mpu_block_until_dmp_data()
+int rc_mpu_block_until_dmp_data(void)
 {
 	if(imu_shutdown_flag!=0){
 		fprintf(stderr,"ERROR: call to rc_mpu_block_until_dmp_data after shutting down mpu\n");
@@ -3368,7 +3278,7 @@ int rc_mpu_block_until_dmp_data()
 	return 0;
 }
 
-int rc_mpu_block_until_tap()
+int rc_mpu_block_until_tap(void)
 {
 	if(imu_shutdown_flag!=0){
 		fprintf(stderr,"ERROR: call to rc_mpu_block_until_tap after shutting down mpu\n");
diff --git a/library/src/mpu/mpu_dev_functions.txt b/library/src/mpu/mpu_dev_functions.txt
new file mode 100644
index 00000000..d5b65882
--- /dev/null
+++ b/library/src/mpu/mpu_dev_functions.txt
@@ -0,0 +1,120 @@
+/**
+ * @file mpu_dev_functions.c
+ *
+ * these functions are not actually part of the library but where used in the
+ * development of the mpu module. They remain here in case they become useful in
+ * the future.
+ *
+ * I repeat, these are NOT part of the mpu module and are NOT accessible by the
+ * user.
+ */
+
+
+
+/**
+ * takes a single row on a rotation matrix and returns the associated scalar for
+ * use by __inv_orientation_matrix_to_scalar.
+ *
+ * @param      row   The row
+ *
+ * @return     { description_of_the_return_value }
+ */
+/*
+static unsigned short __inv_row_2_scale(signed char row[])
+{
+	unsigned short b;
+
+	if (row[0] > 0)
+		b = 0;
+	else if (row[0] < 0)
+		b = 4;
+	else if (row[1] > 0)
+		b = 1;
+	else if (row[1] < 0)
+		b = 5;
+	else if (row[2] > 0)
+		b = 2;
+	else if (row[2] < 0)
+		b = 6;
+	else
+		b = 7;      // error
+	return b;
+}
+*/
+
+/**
+ * This take in a rotation matrix and returns the corresponding 16 bit short
+ * which is sent to the DMP to set the orientation. This function is actually
+ * not used in normal operation and only served to retrieve the orientation
+ * scalars once to populate the rc_mpu_orientation_t enum during development.
+ *
+ * @param      mtx   The mtx
+ *
+ * @return     { description_of_the_return_value }
+ */
+/*
+static unsigned short __inv_orientation_matrix_to_scalar(signed char mtx[])
+{
+	unsigned short scalar;
+
+	scalar = __inv_row_2_scale(mtx);
+	scalar |= __inv_row_2_scale(mtx + 3) << 3;
+	scalar |= __inv_row_2_scale(mtx + 6) << 6;
+	return scalar;
+}
+*/
+
+/**
+ * this was a debugging and development function and purely serves to print out
+ * orientation values and rotation matrices which form the rc_imu_orientation_t
+ * enum. This is not called inside this C file and is not exposed to the user.
+ * left here for future reference.
+ */
+/*
+static void __print_orientation_info(void)
+{
+	printf("\n");
+	//char mtx[9];
+	unsigned short orient;
+
+	// Z-UP (identity matrix)
+	signed char zup[] = {1,0,0, 0,1,0, 0,0,1};
+	orient = __inv_orientation_matrix_to_scalar(zup);
+	printf("Z-UP: %d\n", orient);
+
+	// Z-down
+	signed char zdown[] = {-1,0,0, 0,1,0, 0,0,-1};
+	orient = __inv_orientation_matrix_to_scalar(zdown);
+	printf("Z-down: %d\n", orient);
+
+	// X-up
+	signed char xup[] = {0,0,-1, 0,1,0, 1,0,0};
+	orient = __inv_orientation_matrix_to_scalar(xup);
+	printf("x-up: %d\n", orient);
+
+	// X-down
+	signed char xdown[] = {0,0,1, 0,1,0, -1,0,0};
+	orient = __inv_orientation_matrix_to_scalar(xdown);
+	printf("x-down: %d\n", orient);
+
+	// Y-up
+	signed char yup[] = {1,0,0, 0,0,-1, 0,1,0};
+	orient = __inv_orientation_matrix_to_scalar(yup);
+	printf("y-up: %d\n", orient);
+
+	// Y-down
+	signed char ydown[] = {1,0,0, 0,0,1, 0,-1,0};
+	orient = __inv_orientation_matrix_to_scalar(ydown);
+	printf("y-down: %d\n", orient);
+
+	// X-forward
+	signed char xforward[] = {0,-1,0, 1,0,0, 0,0,1};
+	orient = __inv_orientation_matrix_to_scalar(xforward);
+	printf("x-forward: %d\n", orient);
+
+	// X-back
+	signed char xback[] = {0,1,0, -1,0,0, 0,0,1};
+	orient = __inv_orientation_matrix_to_scalar(xback);
+	printf("yx-back: %d\n", orient);
+}
+*/
\ No newline at end of file
diff --git a/library/src/pinmux.c b/library/src/pinmux.c
index 9c113b1c..f333143f 100644
--- a/library/src/pinmux.c
+++ b/library/src/pinmux.c
@@ -326,7 +326,7 @@ int rc_pinmux_set(int pin, rc_pinmux_mode_t mode)
 }
 
 
-int rc_pinmux_set_default()
+int rc_pinmux_set_default(void)
 {
 	int ret = 0;
 	// bb blue available pinmux
diff --git a/library/src/pru/encoder_pru.c b/library/src/pru/encoder_pru.c
index ff6bd272..f2e72032 100644
--- a/library/src/pru/encoder_pru.c
+++ b/library/src/pru/encoder_pru.c
@@ -20,7 +20,7 @@
 static volatile unsigned int* shared_mem_32bit_ptr = NULL;
 static int init_flag=0;
 
-int rc_encoder_pru_init()
+int rc_encoder_pru_init(void)
 {
 	int i;
 	// map memory
@@ -56,7 +56,7 @@ int rc_encoder_pru_init()
 }
 
 
-void rc_encoder_pru_cleanup()
+void rc_encoder_pru_cleanup(void)
 {
 	// zero out shared memory
 	if(shared_mem_32bit_ptr != NULL){
@@ -69,7 +69,7 @@ void rc_encoder_pru_cleanup()
 }
 
 
-int rc_encoder_pru_read()
+int rc_encoder_pru_read(void)
 {
 	if(shared_mem_32bit_ptr==NULL || init_flag==0){
 		fprintf(stderr, "ERROR in rc_encoder_pru_read, call rc_encoder_pru_init first\n");
diff --git a/library/src/pru/pru.c b/library/src/pru/pru.c
index 738ae5d4..b7ec26f0 100644
--- a/library/src/pru/pru.c
+++ b/library/src/pru/pru.c
@@ -115,7 +115,7 @@ int rc_pru_start(int ch, const char* fw_name)
 }
 
 
-volatile uint32_t* rc_pru_shared_mem_ptr()
+volatile uint32_t* rc_pru_shared_mem_ptr(void)
 {
 	int fd;
 	volatile unsigned int* map;
diff --git a/library/src/pru/servo.c b/library/src/pru/servo.c
index 9ef522cf..e9b3c699 100644
--- a/library/src/pru/servo.c
+++ b/library/src/pru/servo.c
@@ -27,7 +27,7 @@ static int init_flag=0;
 static int esc_max_us =  RC_ESC_DEFAULT_MAX_US;
 static int esc_min_us =  RC_ESC_DEFAULT_MIN_US;
 
-int rc_servo_init()
+int rc_servo_init(void)
 {
 	int i;
 	// start gpio power rail pin
@@ -72,7 +72,7 @@ int rc_servo_init()
 }
 
 
-void rc_servo_cleanup()
+void rc_servo_cleanup(void)
 {
 	int i;
 	// zero out shared memory
diff --git a/library/src/pthread.c b/library/src/pthread.c
index e9968cd3..cbbd7bd2 100644
--- a/library/src/pthread.c
+++ b/library/src/pthread.c
@@ -165,7 +165,7 @@ int rc_pthread_set_properties_self(int policy, int priority)
 
 
 
-int rc_pthread_get_process_niceness()
+int rc_pthread_get_process_niceness(void)
 {
 	int which = PRIO_PROCESS;
 	id_t pid;
diff --git a/library/src/start_stop.c b/library/src/start_stop.c
index 981edd6c..16073a61 100644
--- a/library/src/start_stop.c
+++ b/library/src/start_stop.c
@@ -25,7 +25,7 @@ static void shutdown_signal_handler(int signum);
 static void segfault_handler(int signum, siginfo_t *info, void *context);
 
 
-rc_state_t rc_get_state()
+rc_state_t rc_get_state(void)
 {
 	return rc_state;
 }
@@ -38,7 +38,7 @@ void rc_set_state(rc_state_t new_state)
 }
 
 
-int rc_print_state()
+int rc_print_state(void)
 {
 	switch(rc_state){
 	case UNINITIALIZED:
@@ -61,7 +61,7 @@ int rc_print_state()
 }
 
 
-int rc_make_pid_file()
+int rc_make_pid_file(void)
 {
 	FILE *fd;
 	DIR* dir;
@@ -203,7 +203,7 @@ int rc_kill_existing_process(float timeout_s)
 }
 
 
-int rc_remove_pid_file()
+int rc_remove_pid_file(void)
 {
 	// if PID file exists, remove it
 	if(access(RC_PID_FILE, F_OK ) == 0) return remove(RC_PID_FILE);
@@ -211,7 +211,7 @@ int rc_remove_pid_file()
 }
 
 
-int rc_enable_signal_handler()
+int rc_enable_signal_handler(void)
 {
 	// make the sigaction struct for shutdown signals
 	struct sigaction action;
@@ -244,7 +244,7 @@ int rc_enable_signal_handler()
 }
 
 
-int rc_disable_signal_handler()
+int rc_disable_signal_handler(void)
 {
 	// reset all to defaults
 	struct sigaction action;
diff --git a/library/src/time.c b/library/src/time.c
index b967c4cf..26647144 100644
--- a/library/src/time.c
+++ b/library/src/time.c
@@ -37,19 +37,19 @@ void rc_usleep(unsigned int us){
 	return;
 }
 
-uint64_t rc_nanos_since_epoch(){
+uint64_t rc_nanos_since_epoch(void){
 	struct timespec ts;
 	clock_gettime(CLOCK_REALTIME, &ts);
 	return ((uint64_t)ts.tv_sec*1000000000)+ts.tv_nsec;
 }
 
-uint64_t rc_nanos_since_boot(){
+uint64_t rc_nanos_since_boot(void){
 	struct timespec ts;
 	clock_gettime(CLOCK_MONOTONIC, &ts);
 	return ((uint64_t)ts.tv_sec*1000000000)+ts.tv_nsec;
 }
 
-uint64_t rc_nanos_thread_time(){
+uint64_t rc_nanos_thread_time(void){
 	struct timespec ts;
 	clock_gettime(CLOCK_THREAD_CPUTIME_ID, &ts);
 	return ((uint64_t)ts.tv_sec*1000000000)+ts.tv_nsec;
diff --git a/library/src/version.c b/library/src/version.c
index 5a4f8739..af534ded 100644
--- a/library/src/version.c
+++ b/library/src/version.c
@@ -13,18 +13,18 @@
 				RC_STRINGIFY(RC_LIB_VERSION_PATCH)
 
 
-unsigned int rc_version()
+unsigned int rc_version(void)
 {
 	return RC_LIB_VERSION_HEX;
 }
 
 
-const char* rc_version_string()
+const char* rc_version_string(void)
 {
 	return RC_LIB_VERSION_STRING;
 }
 
-void rc_version_print()
+void rc_version_print(void)
 {
 	printf(RC_LIB_VERSION_STRING);
 	return;