Copyrights 2020-2021 Embedded AMS B.V. Amsterdam, www.EmbeddedAMS.nl, info@EmbeddedAMS.nl

Looking for a more elaborate description of this example? Please visit: https://embeddedproto.com/sensor-example-with-embedded-proto/

Introduction

This repository hosts example code for Embedded Proto, the embedded implementation of Google Protocol Buffers. It is a simple example showing how a microcontroller and desktop pc can communicate over UART. Command messages are send from a desktop script over an UART comport to the MCU.

This example makes use of a FRDM-KE02Z board made by NXP. This board holds an ARM Cortex-M0+ processor. To build the source code and program the hardware MCUXpresso has been used.

The desktop program is a simple terminal python script. This python script let you send commands from a PC to the MCU. You can send the following commands:

1. Pressing 'a' gets the accelerometer data.
2. Pressing 't' gets the thermistor data.
3. Pressing 'l' let you turn on/off the red, green and blue channel from the RGB led.

Installation

1. Install MCUXpresso if you have not already.
2. Install the dependencies required by Embedded Proto. They are listed here.
3. Checkout this example repository including the submodule of Embedded Proto: git clone --recursive https://github.com/Embedded-AMS/EmbeddedProto_Example_FRDM_sensors.git.
4. Setup the environment required for Embedded Proto and the desktop script by running the setup script: ./setup.sh on Linux or .\setup.bat on Windows.

The setup script already does it for you but you can regenerate the source code using the ./generate_source_files.sh or .\generate_source_files.bat script. This is required when you have changed the *.proto file.

Running the code

Connect the FRDM-KE02Z via the usb programmer and use MCUXpresso to build and program the microcontroller. Next find out which comport has been allocated for the FRDM-KE02Z. In the example code below it was ttyACM0. Next go to the desktop folder, activate the virtual environment and run the script.

cd desktop
source venv/bin/activate
python3 main.py --com /dev/ttyACM0

Have fun!