Wired communication to Pi Pico

General
1

I need to send some 'commands' to a pi pico device thats running some custom micropython code over a wired connection from Node-RED running on a RasPi.

Anyone got a good solution to this, I only need a few basic state switch comands so simplest would be to wire 3-4 GPIO lines across and just set one of them high depending on the mode I need to activate on the Pico.

Or maybe a serial connection via GPIO??

Something else?

2

This topic talks about mqtt with micro python, it may help How to receive MQTT data using Subscribe and callback

3

That thread seems to be assuming wifi.

Does MQTT work over a serial port?

4

No, MQTT relies on a network stack (and a broker) so way more overhead than would be needed for a local wired connection!
Also the Pico doesn't have a network interface (its not a PicoW)