I wish to read some modbus coils from my laptop using a modbus slave simulator, and a Photon running the ported modbusmaster library.
I have tried to determine as much info from current threads and keep arriving at the same point… however there are several indications that people have had some successes.
A physical interface is required between photon and 232/485 serial converter at laptop and/or interface inbetween…
What interface (if any) would I use, and How do I connect RX / TX pins to photon?
The modbus master library suggests “D7 is the pin used to control the TX enable pin of RS485 driver” - what does this mean?
EG: One suggestion is to use this: https://www.sparkfun.com/products/10124
I also found this breakout: https://www.sparkfun.com/products/9822 which may be more suitable to bypass MOXA completely.
How does (if at all) this relate / utilise the RX / TX pins on the photon?
Can someone please shed some much needed light on this / recommend drawing for connection would be absolutely appreciated.