About

Ever need a serial port far away from your Raspberry Pi? Wish you could use WiFi to talk to a serial device without having to run a wire? This project is for you.

Installation

npm install -g remote-serial-pico
remote-serial-pico install

Now a server is running on the Pi. If you plug in a Pico to the USB it will install the client code on the pico and make it a remote serial port.

/tmp/pico_1

It's that easy to setup a remote serial port. Each time you plug in a pico, it will be the next pico_N on the list.

Background

Designed to facilitate communication between a remote device (such as a Raspberry Pi) and a device connected via serial to the Pico. It leverages TCP/IP networking to bridge data exchange between the Pico's serial interface and a networked environment. Extend this project using either the node-red-bridge or homebridge-tcp-smarthome.

Pico on-board LED status

• LED blinks repeatedly during the WiFi connection process. Upon successful connection it turns off.
• LED switches on again when connected to the TCP server.
• LED blinks once upon receiving a command either from TCP server or a serially connected device.
• LED turns off when disconnected from the TCP server.

Project Q&A

• Curious about PtyServer?

  • Detects Pico clients upon receiving first packet with pico_{N}, and assigns separate pipes.
  • Sends data available in command pipe to the respective Pico and clears the pipe.
  • Writes data received from Pico into corresponding response pipe.
  • Deletes corresponding Pico pipes upon disconnection.

• Wondering how plugging Pico into the Pi installs PicoSerialClient.py?

  • The udev rule (99-pico.rules) watches for Pico devices connecting to the Raspberry Pi.
  • When a Pico is connected, it triggers another script PicoScriptDeployer.py to run on Pi.

• And what exactly does PicoScriptDeployer do?

  • It fetches wifi-ssid, password, IP, Pico-serial-id and updates the corresponding credentials on config.json. You can also manually update it.
  • Modifies PicoSerialClient.py with the credentials from config.json.
  • Renames and deploys PicoSerialClient.py as main.py for auto-execution on Pico restart.
  • Deploys PicoSerialClient.py to the most recently connected Pico only.

Visual Overview

• Checkout detailed diagram.

  

Credits

Special thanks to Medical Informatics Engineering for their support throughout the development of this project, especially to Doug Horner for his invaluable guidance.