Questions tagged [rs485]

also known as ANSI/TIA/EIA-485, TIA/EIA-485, EIA-485 or RS-485, is a standard defining the electrical characteristics of drivers and receivers for use in balanced digital multipoint systems. The standard is published by the Telecommunications Industry Association/Electronic Industries Alliance (TIA/EIA).

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Arduino UNO and RS485 Communication Problem

I am learning Arduino, a beginner in programming. I want to use Arduino UNO to connect a wind direction sensor RS485. The problem is the output in the serial monitor, the return data from the wind ...
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1answer
931 views

Arduino Uno & ESP32 communication using RS485

I am trying to establish a communication between Arduino Uno ( Master) and ESP32 (Slave) using RS485 protocol (using MAX485 module). I have successfully done this between two Arduino Unos. ...
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136 views

RS485 Serial Communication not working with Arduino

I am trying to control 2 devices with my arduino using RS485 communication. Basically switch on device 1 for 5 seconds when I send 'g' to the master. And switch on device 2 for e3 seconds when I send ...
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199 views

Arduino Modbus slave error

I am trying to use Arduino as Modbus- RTU slave and Raspberry Pi as a Modbus master I have interfaced Max485 (RS485 to TTL converter) with Arduino and Rs485 to USB converter in Raspberry Pi, Initially,...
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0answers
1k views

Pelco D Library for Arduino

Does anyone know of any Pelco D libraries available for Arduino? I already have a PTZ joystick controlling 3 PTZ cameras, but I would like to add an Arduino 'intelligent' controller capable of ...
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0answers
67 views

Multi-drop RS485 device control v1.0 - why is limit for “TIME_BETWEEN_MESSAGES ”?

I am going to use Nick's rolling-master system library (http://www.gammon.com.au/forum/?id=11428) in my home project. For first experiments and testing, I have: - BAUD_RATE = 9600 - max adress = 2 (...
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I am interfacing Amonia Sensor RS485 output with Arduino Mega . not getting any response

I am interfacing Amonia Sensor RS485 output with Arduino Mega but not getting any response. i need to transmit {0x06, 0x03, 0x00, 0x00, 0x00, 0x04, 0x45, 0xBE}; frame to sensor then senor will send ...
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10 views

ESP32 Hardware Serial Flow control and full espressif/arduino-esp32 support

I have a similar issue. I want to use the ESP32 with RS485. I have used the Arduino and this works well assigning pins, but it seems not to allow full use of the UART. I see the new uarts in the ...
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48 views

Can I use an UART RS485 board with DMX simple library?

I want to use DMX512, and found a library DmxSimple, which uses a single (non UART) GPIO pin as output (see DmxSimple.wiki. I currently use a TTL RS485 board, which does not have any TVS/polyfused ...
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0answers
87 views

Reading a simple sensor with Modbus RTU on Arduino Uno

I'm integrating a wind direction- and speed sensor with an Arduino. It communicates over RS485 Modbus RTU, which I don't have any experience with. The documentation is very short, and it just says: ...
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1answer
269 views

Arduino RS485 shield to RS485 temperature & humidity sensor

I’m try to get data from rs485 is not work please advise to me. 1. Try to connect PC usb485 to DY-MD02 is work. Send command “AUTO” or “READ” 2. Try to Arduino rs485 shield to DY-MD02 is not ...
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52 views

NodeMCU Modbus with Dotech DPX200

I've been trying to interface between a NodeMCU and a Dotech DPX200 Pressure Multi-Switch over Modbus RS485 using a MAX485 Module and after a few suggestions I managed to communicate with the Simply ...
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0answers
349 views

SerialEvent with RS485 communication

I am not expert in Arduino programming but i can understand lit bit, while doing review i came across two sets of programs one using serialEvent and one with RS485 library, Now my problem is with ...
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350 views

RS485 Slave doesn't receive any message

I am trying to follow below design to communicate with 2 Arduino Nano, using the example shared here https://github.com/RalphBacon/RS485-Serial-Data-Transmission. When i look at data my slave never ...
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251 views

Unable to read data more than once via Modbus RTU

I'm a newbie to this forum so kindly excuse me for any errors. I'm using an Arduino Uno and Max485 (RS-485 to TTL) to communicate with a Power meter, but I'm able to receive the data from the Power ...
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123 views

RS485 Arduino Communication Issue

Friends, I am trying to achieve half duplex communication between two Arduinos using RS485 Protocol. The hardware I am using is a MAX485 module and an Arduino Uno. I am using the SoftwareSerial ...
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1answer
4k views

Arduino master/slave communication using RS485

I am using Arduino Uno as a Master Device and 3 Arduino Unos as slave devices. I am sending data from each slave to master after every 3 seconds continuously, and is going to execute further logic ...
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0answers
146 views

RS485 Wrong Results in Serial Monitor(Controllino) - Right Results with Logic Analyzer

After searching the internet and trying different examples, I always get the same wrong response in the serial monitor. Picture 1 shows the wrong results. At first i thought it was decimal and I just ...
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0answers
104 views

Arduino as Modbus RS485 slave using only 2 Digital pins

I want to use RX(0) and TX(1) Pins to make Arduino as an RS485 slave. To do this I am using MAX485 IC (Breakout board) https://datasheets.maximintegrated.com/en/ds/MAX1487-MAX491.pdf The problem here ...
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497 views

sending data with rs485

I need to read acceleration data with ADXL335 using ARDUINO MICRO (or NANO) and send this data with RS485 module to another RS485 module connected to an ARDUINO UNO (300m between RS485 modules). ...
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680 views

Arduino Modbus - Rtu slave with Raspberry pi using MAX-485

I am trying to use Arduino as Modbus- RTU slave and Raspberry Pi as a Modbus master I have interfaced Max485 (RS485 to TTL converter) with Arduino and Rs485 to USB converter in Raspberry Pi, Initially,...
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0answers
2k views

Problem in MODBUS RTU communication between two arduino's

I am doing a project to communicate between two Arduino's using MODBUS RTU protocol. I have set one Arduino as the master and the other as the slave. The slave Arduino reads the analog value from a ...
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2answers
139 views

RS485 communication problem

I'm trying to achieve RS485 communication between Arduino Mega and Arduino UNO as specified in following link: https://www.engineersgarage.com/arduino/rs485-communication-between-arduino-mega-and-...