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Merge pull request #10 from dgoffredo/pico-cleanup
Revise the Raspberry Pi Pico sample implementation
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| Original file line number | Diff line number | Diff line change |
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| @@ -0,0 +1,39 @@ | ||
| SCD4x on the Raspberry Pi Pico | ||
| ============================== | ||
| <img alt="Pico W with an SCD41 connected" src="hardware.jpg" height="400"/> | ||
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| In this example, an SCD41 is connected to a Raspberry Pi Pico W on GPIO pins 12 | ||
| (I2C0 SDA) and 13 (I2C0 SCL). The same code will work for any variant of the | ||
| Pico. | ||
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| The following shell session is from an Ubuntu machine that had the Pico plugged | ||
| in to USB in boot select mode. | ||
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| ```console | ||
| $ ls | ||
| CMakeLists.txt hardware.jpg main.c README.md sensirion_i2c_hal.c | ||
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| $ mkdir build | ||
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| $ cd build | ||
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| $ cmake -DPICO_SDK_PATH=$HOME/src/pico-sdk .. | ||
| [...] | ||
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| $ make -j | ||
| [...] | ||
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| $ ls | ||
| CMakeCache.txt cmake_install.cmake generated main.dis main.elf.map main.uf2 pico-sdk | ||
| CMakeFiles elf2uf2 main.bin main.elf main.hex Makefile pioasm | ||
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| $ cp main.uf2 /media/$USER/RPI-RP2 | ||
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| $ screen /dev/ttyACM0 | ||
| The I2C baudrate is 399361 Hz | ||
| Sensor serial number is: 0x8a7e 0xbb07 0x3ba0 | ||
| CO2: 1111 ppm, Temperature: 28.4 C (83.1 F), Humidity: 60.4% | ||
| CO2: 1080 ppm, Temperature: 28.5 C (83.2 F), Humidity: 61.1% | ||
| CO2: 1070 ppm, Temperature: 28.4 C (83.1 F), Humidity: 61.7% | ||
| [...] | ||
| ``` |
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| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -1,77 +1,89 @@ | ||
| #include "../../scd4x_i2c.h" | ||
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| #include <hardware/i2c.h> | ||
| #include <pico/stdlib.h> | ||
| #include <pico/time.h> | ||
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| #include "hardware/i2c.h" | ||
| #include "pico/binary_info.h" | ||
| #include "pico/stdlib.h" | ||
| #include "scd4x_i2c.h" | ||
| #include <stdio.h> | ||
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| /// I2C address | ||
| static int addr = 0x62; | ||
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| // I2C Pins | ||
| static uint sda_pin = 16; | ||
| static uint scl_pin = 17; | ||
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| // This is the main entry for your c application. U | ||
| // is | ||
| int main() { | ||
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| int main(void) { | ||
| stdio_init_all(); | ||
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| // Setup I2c using pins 16 & 17 | ||
| i2c_init(i2c_default, 400 * 1000); | ||
| gpio_set_function(PICO_DEFAULT_I2C_SDA_PIN, GPIO_FUNC_I2C); | ||
| gpio_set_function(PICO_DEFAULT_I2C_SCL_PIN, GPIO_FUNC_I2C); | ||
| // Give us a few seconds to start viewing the output if we're plugged into | ||
| // the computer over USB. | ||
| sleep_ms(3000); | ||
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| // This variable will hold the return status of the function calls. | ||
| // You can separate each function call result into their own variable or re | ||
| // - use this. | ||
| // Setup I2C using GPIO pins 12 & 13. | ||
| const uint desired_clock_hz = 400 * 1000; | ||
| const uint actual_baudrate = i2c_init(i2c_default, desired_clock_hz); | ||
| printf("The I2C baudrate is %u Hz\n", actual_baudrate); | ||
| const uint sda_pin = 12; | ||
| const uint scl_pin = 13; | ||
| gpio_set_function(sda_pin, GPIO_FUNC_I2C); | ||
| gpio_set_function(scl_pin, GPIO_FUNC_I2C); | ||
| gpio_pull_up(sda_pin); | ||
| gpio_pull_up(scl_pin); | ||
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| int status = 0; | ||
| // Initialize driver with i2c address | ||
| scd4x_init(SCD41_I2C_ADDR_62); | ||
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| // Stop any readings if occuring | ||
| status = scd4x_stop_periodic_measurement(); | ||
| int status; | ||
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| // Perform self test | ||
| uint16_t* selfTest = 0; | ||
| scd4x_perform_self_test(selfTest); | ||
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| // Get Serial number 3 parts | ||
| uint16_t one; | ||
| uint16_t two; | ||
| uint16_t three; | ||
| // Stop any ongoing measurement. | ||
| status = scd4x_stop_periodic_measurement(); | ||
| if (status) { | ||
| printf("Unable to stop measurement. Error: %d\n", status); | ||
| return status; | ||
| } | ||
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| scd4x_get_serial_number(&one, &two, &three); | ||
| // Get serial number. | ||
| uint16_t serial_number[3] = {0}; | ||
| status = scd4x_get_serial_number(serial_number, 3); | ||
| if (status) { | ||
| printf("Unable to get sensor serial number. Error: %d\n", status); | ||
| return status; | ||
| } | ||
| printf("Sensor serial number is: 0x%x 0x%x 0x%x\n", (int)serial_number[0], | ||
| (int)serial_number[1], (int)serial_number[2]); | ||
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| // Start the readings. | ||
| status1 = scd4x_start_periodic_measurement(); | ||
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| while (1) { | ||
| status = scd4x_start_periodic_measurement(); | ||
| if (status) { | ||
| printf("Unable to start periodic measurement. Error %d\n", status); | ||
| return status; | ||
| } | ||
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| // Check if data is ready to read | ||
| for (;;) { | ||
| // Wait for the measurement to complete. | ||
| sleep_ms(5000 - 10); | ||
| bool dataReady; | ||
| while (dataReady == false) { | ||
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| status1 = scd4x_get_data_ready_flag(&dataReady); | ||
| do { | ||
| sleep_ms(10); | ||
| status = scd4x_get_data_ready_status(&dataReady); | ||
| if (status) { | ||
| printf("Unable to get sensor readiness status. Error %d.\n", | ||
| status); | ||
| return status; | ||
| } | ||
| } while (!dataReady); | ||
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| // Read the measurement data and convert it to common units. | ||
| uint16_t co2Raw; // ppm | ||
| int32_t temperatureRaw; // millicelsius | ||
| int32_t humidityRaw; // millipercent | ||
| status = scd4x_read_measurement(&co2Raw, &temperatureRaw, &humidityRaw); | ||
| if (status) { | ||
| printf("Unable to read measurement data. Error: %d\n", status); | ||
| return status; | ||
| } | ||
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| // Get the ticks. The scd4x_read_measurement function is giving | ||
| // incorrect data due to the arthimetic | ||
| uint16_t co2; | ||
| uint16_t temp; | ||
| uint16_t humidity; | ||
| status1 = scd4x_read_measurement_ticks(&co2, &temp, &humidity); | ||
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| // Arithemtic to change raw data into information | ||
| int tempInCelsius = -45 + 175 * temp / 65536; | ||
| int tempInFarenheit = tempInCelsius * 1.8 + 32; | ||
| int humidityPercent = 100 * humidity / 65536; | ||
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| // Print results to terminal (output) | ||
| printf("C:%d,T:%d,H:%d", co2, tempInFarenheit, humidityPercent); | ||
| const int co2Ppm = co2Raw; | ||
| const float temperatureCelsius = temperatureRaw / 1000.0f; | ||
| const float temperatureFahrenheit = temperatureCelsius * 1.8f + 32; | ||
| const float humidityPercent = humidityRaw / 1000.0f; | ||
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| // Sleep for 5 seconds. | ||
| sleep_ms(5000); | ||
| printf("CO2: %d ppm, Temperature: %.1f C (%.1f F), Humidity: %.1f%%\n", | ||
| co2Ppm, temperatureCelsius, temperatureFahrenheit, | ||
| humidityPercent); | ||
| } | ||
| } |
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