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 sending data over MAX485

I would like to introduce myself as a student from Czech Republic. I'm currently I'm working on a Meteostation project. I've got Arduino set up, with plenty of weather sensors, as well as WH1080 ...
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Arduino throwing error while using modbus RS485 code

I have been trying to make a communication with my industrial drive. All I want to do is read a few values of drive, like current, voltage etc. For that I am using a library: I don't understand why ...
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RS485 bus voltage?

Does anyone know the voltage situation regarding multi-drop nodes on an RS485 bus please? Nick Gammons RS485 article shows 2 different hardware configurations, one using 5v devices, and another using ...
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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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2answers
5k views

Long Distance Communication with Arduino

I am reading the value of six potentiometers with a TX Arduino and receiving that data and applying those numbers to a motor using serial. It is working fine through TTL but I am going to need to do ...
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1answer
481 views

Modbus master arduino code is throwing weird errors on upload

I am using the following https://code.google.com/p/simple-modbus/ arduino master library code. In order to communicate with my industrial drive. All seems right but I am getting some weird errors. I ...
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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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247 views

Interfacing Gammon's RS485 with computer

I'm using the non-blocking RS485 Gammon's library for Arduino (as shown at http://www.gammon.com.au/forum/?id=11428) to handle the communication between some arduinos. Now I'm having trouble to add a ...
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Problem in RS485 Communication between Arduino and PC

I'm trying to sending and receiving data via RS485 communication. Interfacing Arduino and PC(laptop) using SN75176 RS485. I wrote a program to send a string "Hello" from arduino via Tx pin. My ...
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Serial: What is different between Gammon's RS485 (blocking) and RS485 “non blocking” libraries?

The RS485 master-slave communication library on Nick Gammon's page http://www.gammon.com.au/Arduino/RS485_protocol.zip is working for me OK, but on the same hardware wiring is not working for the non-...
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Modbus Communication protocol for Arduino as Slave

I have an Arduino Uno board, with these components: rs-485 Modbus module shield Multiprotocol radio shield board for Arduino In addition I have a level sensor which reads either 1 when it is above ...
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1answer
84 views

RS-232 is a protocol or a cable?

RS-485 and RS-232 are a type of communication protocol or a type and cable? I studying these serial communication protocols and each place refers to the RS-232 / RS-485 in different ways. Some ...
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How to interconnect multiple Arduinos with a Rpi to control home-lights/switches

While planning the lightning infrastructure (wall-switches and lights) of my new home (it's still under-construction) I choosed to go through the "automated route" way and due to my background (I'm an ...
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How can I get a unique address for all my Arduino boards while in RS485?

My attempt is to know how to identify the board I'll be sending parameters to in a serial connection like rs485. I'm asking because I will have about 11 or so mcu's as "Rx slaves" while my pc is the ...
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2answers
619 views

Standard Length Messages over RS-485

I am a bit confused. So I want to send messages between two arduinos over RS485, but these are not fixed length, naturally, I have to send the length of the message or add a delimiter to understand ...
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1answer
548 views

How to solve Atmega 16A Serial write (println) hang with Arduino Uno firmware?

For doing some experiments I bootloaded an Atmega16a with Arduino Uno. I am powering my Atmega16a from Arduino UNO. I am not using any external clock. Atmega16a is connected to a breadboard. For ...
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667 views

RS-485 with Arduino

I have two Arduinos on a RS-485 line, one acting as a Master and the other as a Slave. The Master simply transmits information to the Slave, which parses it. They work fine when the Master is ...