MeshPico
A small project designed to be used for development of an IOT embedded device. This makes a Raspberry Pi Pico simulate a Json RPC service that can be connected to over hardware serial 1.
Usage
This project has two RPC functions: getChassisSerialNumber and setChassisSerialNumber. These functions abide by a global named SN_LENGTH which defines the max length of the serial number.
Any request made to the device must also be less than a 1023 characters delimitter to delimitter (If you hit that what are you even trying to do!).
setChassisSerialNumber
This method allows you to set the serial number of the unit. The serial number must be less than SN_LENGTH. If there was an error (most likely too long of a serial number) then it will return an error message. If for some reason the device has issues with flashing the new serial number then it will return false.
Normal Operation:
--> {"jsonrpc": "2.0", "method": "setChassisSerialNumber", "params": {"serialNumber": "8134534d-509c-45ae-b093-49c65c868c5f"}, "id": 1}
<-- {"jsonrpc": "2.0", "result": true, "id": 1}
Failed Flashing:
<-- {"jsonrpc": "2.0", "result": false, "id": 1}
Error Message:
<--{"jsonrpc": "2.0", "error": {"code": -32602, "message": "Invalid Request"}, "id": "1"}
getChassisSerialNumber
This method returns the stored serial number in the form of a string. The returned id string has a max length of SN_LENGTH. If there was an error with parsing the serial number (some sort of flash error) then it will return an error code
Normal Operation:
--> {"jsonrpc": "2.0", "method": "getChassisSerialNumber", "params": {}, "id": 2}
<-- {"jsonrpc": "2.0", "result": "8134534d-509c-45ae-b093-49c65c868c5f", "id": 2}
Error Message:
<--{"jsonrpc": "2.0", "error": {"code": -32603, "message": "Internal Error"}, "id": "2"}
Prerequisites
This was developed in an opensource platform in the PlatformIO IDE. This IDE can be used standalone or installed as a VS Code extension.
You need to have git installed for PlatformIO to be able to pull the custom platform.
This project uses a library that provides Json serialization and RPC bindings called mjson.
The custom platform can be found here and is still in beta.
Setup
- Open PlatformIO and navigate to the platforms pane
- Click on the Advanced Installation button and paste:
- Install the platform
- After installing the platform clone this repo into a sandbox folder
- Open the repo in the IDE and PlatformIO should detect the pio project and populate the build and upload options
- There are two properties you might need to change in the platform.ini
upload_port: this defines the path to the pico, the default is E:/
monitor_port: the comport that is used to debug the pico, default is COM3
Building & Uploading
After setting up the repo there are two main PlatformIO functions that matter, building and uploading.
- In project tasks navigate to:
Tasks -> raspberry-pi-pico -> General
- When you are ready to build the project, use the Build button to compile the binaries
- From there hold down the button on the pico and plug the microcontroller into your laptop
- Once plugged in you can release the button, it should appear as an external storage device
This should be your upload_port property
- After compiling your binaries, use the Upload or Upload and Monitor buttons to upload the code
Issues
Please refer to the wizio-pico wiki for help with issues involving environment setup.