With all these MCU’s needing to connect to real world stuff.. electric valves, heaters, motors and the like. I need a versatile IO board that I can hook up to an Arduino, Raspberry PI, Beaglebone or Carambola. All of which have an i2c bus. So armed with a MCP23017, I’ve come up with this IO board.
- 8 Relay outputs ( relays are spec’ed at 240V 5A )
- 8 Digital inputs ( switched input, closing to ground )
- Selectable i2c address ( up to 8 of these on the one i2c bus )
- All running from +5V ( relays can be powered from an alternative power supply if 5V coils are not to hand )
- Single layer, through hole construction ( old skool! )
I’m loving KiCAD… Over the last few schematic captures I now have a handle on libraries, this time I got my head around modules as I couldn’t find the pads for the relays I wanted to use. Even better, I managed to layout the board on a single sided PCB! Here it is:
All the files are here: i2cRelayBoard
Now I’ve got to get all the clobber to make my own PCB’s… It’s been a while since I’ve had to do that…!