ISO RS485 on M5dial

mukul_100_

Hi, So i have a ISO RS485 and i need to get modbus working on it. The primary problem im facing is that the module is UART based and by my understanding M5Dial has I2C and GPIO ports. Is it as simple as hardware serial and setting 1 and 2 pins to UART or is there something else to it
Also it would be great help if there are any modbus library that can be used.
Thank You

robski

@mukul_100_ what software you planning to use?
see uiflow2 init example

mukul_100_

i am using platformio right now. thanks

felmue

Hello @mukul_100_

please find an example here with M5Dial and RS485 unit controlling an ACSSR relay via Modbus protocol.

Thanks
Felix

mukul_100_

@felmue hi felix sorry for the late reply, finally got a chance to get back to this

i studied the example but not sure if i understood how to implement the master slave concept through this and also there is a error thrown in
RS485Class RS485(Serial2, GPIO_NUM_1, GPIO_NUM_2, -1, -1);

as there are only 4 arguments accepted by the class
also serial2 needs some tweaking for esp32 right?
thanks

felmue

Hello @mukul_100_

I linked the incorrect variants for RS485 and Modbus libraries. Sorry about that. I fixed the example. The libraries I used are the ones from M5Stack.

https://github.com/m5stack/ArduinoModbus
https://github.com/m5stack/ArduinoRS485

Thanks
Felix

mukul_100_

@felmue Hi felix
the changes you mentioned are in the same example code that is linked above?

felmue

Hello @mukul_100_

yes.

Thanks
Felix

mukul_100_

@felmue ,did you make any changes in the RS485.h file
along these line 46
#else
#ifndef RS485_DEFAULT_DE_PIN
#define RS485_DEFAULT_DE_PIN A6
#define RS485_DEFAULT_RE_PIN A5
#endif

thanks,
Mukul

felmue

Hello @mukul_100_

No.

I think you are still on the library I incorrectly linked to in my example before.

Incorrect library: https://github.com/arduino-libraries/ArduinoRS485

Library I used: https://github.com/m5stack/ArduinoRS485

Thanks
Felix

mukul_100_

@felmue Hi, felix i got it working finally. The issue is, on platformIO the library Arduinomodbus library and ArduinoRS485 library are the arduino ones and not the m5stack ones which is why i was getting error.
A fix to this was to just replace the internal files of library to the m5stack ones from github.
Thank you for the help.