Lopy with modbus
Which pins do I need to connect on the board to do modbus ?
@svonbentzel No, for me too. I have use this one for get modbus run fine:
@svonbentzel No, i dont know witch which pycom board your talking about, but ESP32 RX/YX pin are 3.3V TLL level, modus is RS422 or RS485 or RS232. RS422 and RS485 are very close electrical level (on a differential line), RS232 is +12V and -12V so you need an adapter and you must choise it to be on same physical level of the sensor you plan to use.
philwilkinson last edited by
Have anyone had success with this modified modbus library?
svonbentzel last edited by
can I connect the modbus device directly to the Pycom Board.
or did I need a additional modus RS485 adapter?
@abhishek2101 RS485 OR RS232 it depend of your sensor.
MAX3232 or SN65HVD10 for exemple is good component.
@Eric73 I will be using Modbus RTU, can you suggest me a good RS485/RS232 transceiver ?
Hi, in fact it's depends if you do modbus over tcp (so it's wifi and no pin) or modbus RTU using uart pin (and RS232/RS485 transceiver don't use directly your uart pin!) you have selected when you created your modbus object.
According to source code this is an valid example.
uart_id = 0x01 modbus_obj = Serial(uart_id, pins=('P9', 'P10'))
It's seem that pycom documentation lake information about the initialization of this object
can anybody help please ?