PIC Domotic station

I use this Microchip’s PIC program made in C to control my domotic system for quite some time now, and I think it’s ready to be published.

Below is the readme file, to read the last version, directly go to :


PIC Domotic station


PIC program for a domotic station controlling two temperature sensors, multiple relay, a USB port (for power only) and connected to a PC using UART to receive its instructions.

It uses a PIC18F23K20 but should work on most of them. The PC sends simple commandes through /dev/ttyUSB0 like “A 32” to enable the device 32, or “E 32” to disable it. “T” to get temperature, … See the source code in main.c.

This is MPLAB X IDE project. The only usefull file is in fact main.c, the rest is auto-generated, but I include them if someone would want to directly program the binaries, for example.

Technology used

If you’re looking for sample code, you may find here how to :

  • Use the UART to communicate with a PC (UART is connected to a “uart usb” module very cheaped that you can find on ebay for example) .
  • Use the watchdog timer to ensure a device reset if something goes wrong
  • Use Brown-out to jump to do an interrupt and do “something” (blink in my case) if the voltage goes below some threshold
  • Use the ADC to read the temperature given by two LM35
  • Read/write to eeprom
  • Control a 5V relay board with a 3.3V relay board using NPN Transistors (when I’ll add the schematic though)

The python script used to manage the PIC controller is available athttps://github.com/tbarbette/monitoring/blob/master/scripts/relay.py and a small HTTP server allowing you to remotely control it is available athttps://github.com/tbarbette/monitoring/blob/master/scripts/server.py