buschg/protobuf-compiler repository overview

⁠protobuf-compiler

Dockerized protobuf compiler for Arduino and python

Example usecase: Measure weather data with a sensor attached to an ESP32 which transmits the data via MQTT (encoded in protobuf format) to a Raspberry Pi. On the Raspberry Pi, the data is decoded by a python-script and saved in a database.

Proper configuration of protoc (https://developers.google.com/protocol-buffers⁠) and nanopb (https://jpa.kapsi.fi/nanopb/⁠) turned out to be quite messy. Especially, since my Mac refused to execute the pre-compiled nanopb. Dockerizing the compilers makes this task much easier and increases reproducability.

⁠1. Create .proto file

Define your protocol buffer message type in a .proto file, e.g. test.proto:

syntax = "proto2";
 
message TestMessage {
    required int32 test_number = 1;
}

⁠2. Compile for Arduino/ESP8266/ESP32 etc. (nanopb)

Run the following command in the directory that includes your proto-files to compile all your proto-filed. If you have several and only want to compile one, replace the *.proto by the file name.

docker run -v $(pwd):/protos -it --rm buschg/protobuf-compiler:latest protoc --plugin=protoc-gen-nanopb=/nanopb-0.4.1-linux-x86/generator/protoc-gen-nanopb --nanopb_out=/protos --proto_path=/protos/ *.proto

You will find the compiled versions in the same directory as test.pb.c and test.pb.h.

⁠3. Compile for python

Similarly, run the following command to compile your proto-files for python:

docker run -v $(pwd):/protos -it --rm buschg/protobuf-compiler:latest protoc --python_out=/protos --proto_path=/protos/ *.proto

You will find the compiled version in the same directory as test_pb2.py.