Please help me. I did everything. So, I have an RS485 (pH sensor) and MAX485. The RS485 (pH sensor) needs to receive data to the MAX485. My first try is not working when I diagnostic tested it and said is failed. By the second try is I fix the wirings, but failed. By the third try is I fix thr wirin…

Welcome to forum. You wrote seven times it failed but not What failed. How is your wiring exactly done, what code you use and what's the output with that code?

what host microcontroller are you using? are you using a RS485 module, e.g. [image] or have you built a PCB with an onboard MAX485

Hi @dannyflarence ! "I did it right and it worked immediately." Would you consider this answer helpful? I guess not. But it is mirroring your failure description...:slight_smile: If you want sound help please supply all relevant information: Software: Development environment (Arduino IDE? Ver…

[image] dannyflarence: I fix the wirings, but failed. *Welcome! Apparently, you did not properly "fix the wiring." The number of different ways you have tried connecting it indicates that it is probably still wired incorrectly, or you may have damaged something in the process. Post an annot…

[image] dannyflarence: RS485 (pH sensor) needs to receive data to the MAX485 RS485 needs to SEND data TO the MAX485. Be sure you are connecting the 485 devices for SIMPLEX communication (link HERE ). [image] (NOT half-duplex or full duplex , unless data is to be sent and received) Simplex …

rereading post 1 the dev board is a UNO R4 WiFi program connecting UNO R4 WiFi to a RS485 module then via RS485 to a FDTI RS485 cable // UNO R4 Serial1 to RS485 bus // uNO R4 Serial uses USB Serial1 uses D1/TX and D0/RX // connections // UNO R4 5V to RS485 VCC // UNO R4 GND to RS485 GND // UNO…

I don't know anymore on to connect an RS485 to MAX485

Projects General Guidance

robtillaart August 11, 2026, 10:43am 2

Please read - How to get the best out of this forum

and provide all information you have, code, schematic, sensor specification etc.

Topic		Replies	Views
RS485 without MODBUS using UNO R4 WiFi General Guidance	36	747	July 3, 2025
MAX485 to Arduino ATmega2560 General Guidance	10	291	February 24, 2025
Connect arduino uno with MAX485 Networking, Protocols, and Devices	3	1103	October 18, 2023
UNO RS485 communication between master and slave General Guidance	6	232	June 30, 2025
Connection from esp32 to rs485 to ttl Networking, Protocols, and Devices	6	209	May 17, 2026

I don't know anymore on to connect an RS485 to MAX485

Related topics