If I stack two 16-relay hats can I use the RS485 on both boards? As I understand, the Raspberry PI supports two UARTs, meaning I should be able to connect two RS485, but that will only work if I'm able to re-route them to separate pins on the hat from the available jumper pins. I have more than 32 devices I want to connect to that's why I'm asking.
RS485 from multiple boards
- Thread starter haig
- Start date
Hi,
The 16Relay card, as you can see from provided schematics, contain jumper only for the RX signal so there is no way to reroute the TX signal without cutting a trace on the PCB. And yes, Raspberry has multiple USARTS ports but you have to connect them to the RS485 transceiver.
One irreversible idea is to use the normal USART port (serial 0) for the first card and cut the pins 8 and 10 of the 40 pins connector so the same serial port does not connect with the next card. After this at the second card put jumper wires from serial 0 (which is not connected to the raspberry) to the next serial port.
The 16Relay card, as you can see from provided schematics, contain jumper only for the RX signal so there is no way to reroute the TX signal without cutting a trace on the PCB. And yes, Raspberry has multiple USARTS ports but you have to connect them to the RS485 transceiver.
One irreversible idea is to use the normal USART port (serial 0) for the first card and cut the pins 8 and 10 of the 40 pins connector so the same serial port does not connect with the next card. After this at the second card put jumper wires from serial 0 (which is not connected to the raspberry) to the next serial port.
Ah, didn't realize there was a schematic available, awesome, getting positive vibes from this company! Okay I see, I will either go that route or use the first port as is and then add an additional small UART->RS485 breakout next to it. I think there are also RS485 extenders that I could use perhaps.
I am not sure what you mean by "RS485 extenders" but looking at the schematics you can chose the solution.