Shows how to use ESP32 RMT with an Ultrasonic HC-SR04 sensor
This sample intializes the SR04 device and sends 10us pulses and then measures the width of the received pulse to calculate the distance in meters. The sample contains a SR04 class which can be used directly in your own applications.
The SR04 has 4 pins.
Connections VCC - 5V or 3.3V depending on version of SR04 GND - Ground signal TRIG - Any available GPIO pin capable of output ECHO - Any available GPIO pin
Note: When connecting ECHO to ESP32 pin be aware that if using a 5v version of SR04 a level shifter should be used. OK for short tests but for long term use connect a resistor between SR04 output and ESP32 pin(10K) to limit current.
Note: This sample is part of a large collection of nanoFramework feature samples. If you are unfamiliar with Git and GitHub, you can download the entire collection as a ZIP file, but be sure to unzip everything to access any shared dependencies.
Any ESP32 hardware device running a nanoFramework image with HC-SR04P 3.3V version ( HC-SR04 5v version )
- If you download the samples ZIP, be sure to unzip the entire archive, not just the folder with the sample you want to build.
- Start Microsoft Visual Studio 2019 (VS 2017 should be OK too)/2019 and select File > Open > Project/Solution.
- Starting in the folder where you unzipped the samples, go to the sub folder for this specific sample. Double-click the Visual Studio Solution (.sln) file.
- Add the connection and certificate information to the program.
- Press Ctrl+Shift+B, or select Build > Build Solution.
The next steps depend on whether you just want to deploy the sample or you want to both deploy and run it.
- Select Build > Deploy Solution.
- To debug the sample and then run it, press F5 or select Debug > Start Debugging.