Here is the chaotic mess that is my redneck-robot, yes it’s a mess but it’s working.
Bot has 2 36 volt batteries, 2-4 buck-converters for step down voltage. 1 old-school wrt54G router from yesteryear (running customized DDWRT firmware) 4 motor controllers controlled by slave raspberry pi 3 (raspian buster) with 4 8-channel relays (GPIO, yes I found GPIO the most reliable for this so far, I tried other motor control methods), 4 350 watt motors from cheap hoverboards, and one master raspberry pi 4: hosting Rhasspy’s Docker container, a standalone Apache Lamp server (for when things are local), python 3, one (GPIO) 8 channel relay, 1 adafruit ultimate gps, 6 ultrasonic distance sensors, 1 raspi-cam with inferred, 2 temp sensors (for the LIPO batteries mostly), 1 real-time clock, 1 hologram IOT modem (used when things are not local-or script chooses cheaper internet if available), 1 simple analog stereo speaker, one usb sound card for the mic.
The Rhasspy stuff is using command mode for intents (sent to a local python3 script and often posting php scripts via the requests python library when it needs to do communicate with the web server based control system.). I’m using pico voice, and a customized snowboy for the wake-word. The bot is often using Rhasspy-api via curl commands to make smart a** comments.
Yes, building a nice wiring harness is on the to do list (meanwhile -complete chaos).
Anyway here is a pic of the robot dolly while some development was going on.