Hello. Just bought two IO PI Zero boards and im trying to make it work correctly. I have to use 6 - 7 16ch relay boards so i had idea to connect those IO PI boards with relay board pins with 2.54mm socket.
Otherwise i would have to connect 80, 1m cables from IO PI Zero expander to relays.
I've made also one extra hole in IO PI pcb to solder pcb ground to socket pins. Now ground of IO PI and relay board are connected.
The relay board have 12v power supply and 5v inverter, I had powered IO PI from those 5v, but raspberry didn't found and device.
When i connectect 3,3v from raspberry it worked, all 16 relays are working but still have some questions and one issue.
1) I dont wanna force raspberry to power any device, so i have to power IO PI Board with 5v and 3,3 also ?
2) I use wiringpi to control of this board with command: gpio -x mcp23017:100:0x20 mode 100 out ... till 15 then i used
gpio -x mcp23017:100:0x20 write 100 ( 1 or 0 ) to change state and its working well when i'm turning on relays.
When all relays are ON i can't turn off any of them, until i'll first turn off 15, but then 8 relays are turning off, so i'm consfused.
Theres also Interrupt A and Interrupt B thing, so don't know what to do rignt now.
I'll be glad for help.