I want to receive data from three different RFID readers (UART TTL) with one Raspberry Pi.
Due to the fact, that there is a distance about 100m cable length between the RPi and each device, I use a RS485 converter with the RFID reader
https://www.androegg.de/?product=rs-485 ... -converter
At the RPi I use a RS485 to UART Hat which works perfectly.
When I connect one of the readers with the RS485 converter to the RPi's RS485 interface I can address the /dev/ttyAMA0 serial port via python and receive data transmitted by the reader.
My problem is, that i am not able to find out the hardware setup to connect more than one rfid reader to the system and receive data.
I read a lot about RS485 and half duplex and multiple senders All of them use a paralell wiring setup. I tried to connect the readers paralell to the RS485 bus but doing this, I do not receive any signal anymore.
Can anybody please help me out? I can't find the error I'm obviously making
Thank you for helping me out