SEN0711 always timeout — no response via RS485 adapter
ber 2026-09-02 12:57:04 24 Views1 Replies Hello,
I am using the SEN0711 Water Quality Ammonia Nitrogen, pH and
Temperature sensor with the Gravity Active Isolated RS485 to
UART Signal Adapter Module. I am consistently getting a timeout
error and zero readings on both Arduino UNO and ESP32.
i already tried and follow the official wirings and code from the tutorial.
Thank you for your help.
2026-09-02 15:39:56 
Jason.Miao
The default baud rate is 4800, not 9600 — make sure your code has sensorSerial.begin(4800). The wiki sample uses 4800 and the comment says "do not change it."
If the baud rate is correct, swap the A and B wires. RS485 timeout is almost always A/B reversed. The yellow wire goes to A, blue to B on the adapter.
Jason.Miao 