Questions tagged [communication]

for questions about communication between multiple devices.

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13
votes
3answers
33k views

What are the fundemental differences of different Bluetooth modules for beginners?

I'm a beginner to microcontrollers and electronics, albeit not really to computers and programming. Starting out with the Arduino, I came to a point whereby I'm really interested in getting my ...
11
votes
2answers
33k views

Difference between /dev/ttyACM0 and /dev/ttyS0 (Arduino IDE ports under Linux)

I use the Arduino IDE to upload sketches to my Arduino Uno. My OS is Linux Ubuntu 14.04 LTS. The Arduino IDE has two ports by default for communication with the Arduino Uno: /dev/ttyACM0 /dev/ttyS0 ...
8
votes
6answers
23k views

Two Arduinos Send data via Analog Pin?

What I want to do is allow Arduino A to send some constant value to Arduino B. I sense something inherently wrong with my approach, but I cant figure out what it is. So in the diagram below you will ...
7
votes
4answers
6k views

Options for communicating between Arduinos

I'm looking to communicate between ~5-10 Arduinos to send commands and data between them. By "Arduino" I mean the ATmega328 programmed using the Arduino programming framework. Each of the devices ...
5
votes
2answers
665 views

Is the arduino hackable when using communication shields?

Let's say I have an arduino Uno connected to a W5100 ethernet shield. The arduino communicates with the ethernet shield using the tx0 and rx0 pins. When I upload a new script to the arduino using USB, ...
5
votes
3answers
22k views

Sending a value from one arduino to another

I wonder if it is possible to send a value from one arduino to another. Basically, I have one arduino measuring let's say weight, but I want to display that value using an lcd in another arduino. ...
5
votes
2answers
4k views

Programmatically Change Arduino Com Port Name

I have some devices that, when I plug in, will display a unique name, usually a serial number, as opposed to "COM #" is there any way I can have my Arduino Uno (or Mega) give itself a different name ...
5
votes
4answers
455 views

Why/when to use IoT publish/subscribe protocols rather then RESTful HTTP?

I am sending data (GPS coordinates) from Arduino once a minute with HTTP POST request to REST API (in OpenShift PaaS). Data is then stored to MySQL db. Would so called "IoT" publish/subscribe ...
5
votes
1answer
145 views

How can I automatically get the time from the computer into an alarm clock (starts at 00:00 when plugged in)?

Okay so I did this project from Fritzing first in my circuits.io project then on the arduino itself, it all works fine just how I wanted it. But here is what I wanted to add, as you can see when you ...
4
votes
2answers
2k views

Does data coming in on Arduino serial port store for some time?

I am using Arduino Uno and my question is when data is coming on Rx pin and at that time our program is not checking Serial.available() Then after some time the program will check Serial.available()....
4
votes
5answers
11k views

MQTT client on Arduino + SIM900

I have used the pubsubclient library for Arduino for communicating with an MQTT broker in the past, however the library works only with Ethernet connecction. I need to use GSM in my application and am ...
4
votes
3answers
1k views

Arduino Unreliable Serial communication

After reading the following 2 articles: https://hackingmajenkoblog.wordpress.com/2016/02/01/reading-serial-on-the-arduino/ https://hackingmajenkoblog.wordpress.com/2016/02/04/the-evils-of-arduino-...
4
votes
0answers
65 views

What’s the most stable digital communication protocol for sewable electronics?

I’ve spent the past few days trying researching communication protocols and I have a few issues. With sewable electronics, you need to work with cables with a fairly high resistance that are ...
4
votes
2answers
691 views

Using Arduino and XBee at the same time

I have 2 Arduino Unos, 2 XBees and 2 Wireless Proto Shields. The first setup has a humidity/temperature sensor (SHT21P) and it writes data to serial and it works (I've tested it). Now, the other ...
3
votes
4answers
13k views

How to pad an ascii number with leading zeros?

I need to include a 3 digit ascii representation of message length number in the message header, but I am having difficulty trying to pad the number with leading '0' zeros in order to keep the number ...
3
votes
5answers
27k views

How to have an Arduino communicate with 3 other Arduinos?

I was wondering how I can get 4 Arduinos in total to communicate with each-other through a wired connection. The goal is to have the master Arduino send a number 0-100 to each of the other Arduinos. ...
3
votes
3answers
124 views

Using several Arduinos simultaneously

I'm working on a project where I need to control the light of 5 buttons as well as listen when each button is switched on/off by the user. I would furthermore like to provide feedback on an OLED ...
3
votes
1answer
6k views

Sending string over serial to nodejs app. Why does it get chunked?

I'm sending a string from my sketch over Serial port as follows: Serial.println(F("Found ILI9341 LCD driver")); On the other side, I have a nodejs app using the serialport npm module, with something ...
3
votes
2answers
6k views

Arduino Serial library (Synchronous or Asynchronous?)

On an Arduino 101, I have this code running: void setup() { pinMode(2, INPUT); Serial.begin(9600); } int counter = 0; void loop() { Serial.print(millis()/1000); Serial.print("\t"); ...
3
votes
2answers
2k views

Could I Connect many Arduino Nano boards together?

I want to know if I could connect many Arduino Nano boards together (Example : 10 boards ) , Also i want to know if there is any problem in Communication between them using I2C , could this affects ...
3
votes
2answers
1k views

433 MHZ connection between two Arduino (nano,uno) fails after some time

The goal of this part of my project is to establish a wireless connection between an Arduino nano and an Arduino uno. For this I use 433 MHZ receiver and sender. The nano sends, the uno receives and ...
3
votes
2answers
7k views

Difference between Wire.setClock() method and TWBR method for changing I2C Frequency

I want to change the I2C frequency of my Arduino Mega 2560. I did find two methods. One method is to change the TWBR variable after Wire.begin(). The other one is to use Wire.setClock() after Wire....
3
votes
2answers
1k views

Arduino cluster functionality - feasibility advice for arduinos to communicate using variable-length long strings?

My apologies. This is my first time on this site and I wasn't even aware that it wasn't some sort of discussion forum until receiving the automated response message to my already submitted vague and ...
3
votes
2answers
1k views

Does an I²C IO Expander needs additional resistors for outputs?

I have following setup (see also schematic in the end) Arduino Nano is connected via I²C to the PCF8575C (link) IO Expander. Both, SCL and SDA have 10kOhm pull-ups to 5V. The Expander pins are ...
3
votes
1answer
811 views

Use Arduino to transmit signal to a vibrating pager

I am an engineer at a machine shop. When a machine stops running, I want to be notified via a vibrating pager (like at restaurants). My plan is to attach the arduino board in the machine and when the ...
3
votes
2answers
14k views

Is the SIM900 3G? Or is the SIM900A able to connect to 3G?

I would like to state that I am not familiar with the whole cellular connection thing. But I was wondering if the SIM900/or/SIM900A is 3G and will work with PTel Mobile. I need this Arduino to be ...
3
votes
1answer
102 views

Identify connected PC per Arduino

Question: Is there a way to collect any data (e.g. MAC addresses, installed devices, driver versions, etc.) from a PC by simply connecting an Arduino via USB to it, so that this PC can be clearly ...
3
votes
0answers
91 views

Can I configure pairing for HC-05 and Arduino, and use the HC-05 without Arduino after?

I have a system that is outputting data via its serial, and I need to relay that data to my PC wireless-ly. If I were to setup an Arduino and HC-05 at the system's side to relay the data, that would ...
3
votes
2answers
1k views

Can't upload to arduino boards anymore

I have been working on several projects recently an made hundreds of uploads to several different boards. I haven't had any issues to speak of. Now I cannot upload. I have tried: Disconnect all ...
3
votes
2answers
1k views

M0 pro: SPI communication, code works on Uno, but not in M0. Using ICSP port

I am trying to establish a communication between a sensor and a M0 -pro using SPI. The code : #include <SPI.h> unsigned int result = 0; void readAngle(); void setup() { ...
3
votes
0answers
5k views

HC 08 Module with Arduino Uno [closed]

I recently bought the HC 08 Bluetooth module (link here). As the specs state, this module supports Bluetooth 4.0 which indicates that it supports BLE (Bluetooth low energy). My goal is to be able to ...
2
votes
4answers
175 views

Can an Arduino Micro receive commands from another microcontroller when hardwired together?

I plan to build functioning reaction wheels, controlled by an Arduino Micro. Ideally, I'd like to have the reaction wheels, and the micro, be a single unit which would receive external commands from ...
2
votes
3answers
43k views

Make a PC graphical interface for Arduino - Any easy software? [closed]

What's the best/easiest software to make a PC-Arduino interface? Ideally, I need to create a .exe that shows up a simple graphic interface, where the user can display data acquired from sensors ...
2
votes
2answers
2k views

send more than one byte at a time SPI Arduino

I have recently been trying to send integers via SPI between two arduino Uno's. I am using the first example of Nick Gammons tutorial, and trying to modify it to get a basic understanding of how to ...
2
votes
2answers
183 views

Sending minimal data between two Arduinos far away from each other

Problem: I need to send small integer numbers (single-digit numbers suffices) between two arduinos located approximately 50-60m away from each other. The connection must be made through cables. I have ...
2
votes
2answers
21k views

Arduino ModBus RTU master communication with Power Meter problem

i have an arduino UNO with RS485 module. I have made this connection: And i have an problem with communication of this module with power meter "InePro PRO-1Mod" (datasheet) over ModBus protocol. I ...
2
votes
3answers
4k views

Serial Comm. timing issue between Arduino and Pyserial

This is my first post to Stack Exchange so please forgive any formatting errors. I am conducting an experiment that has 7 total sensors: 5 thermocouples, 2 humidity sensors and 1 pressure sensor. I ...
2
votes
2answers
56 views

Ensure board is always on the same port?

I want to make a VB.NET program to communicate over serial with the board, but I need to be sure it knows which port. Instead of programming in more advanced methods of verification, for this project ...
2
votes
1answer
127 views

Long term connection between Arduino and computer

I am looking to make indicator lights for my computer to indicate things such as system load, IO usage, et cetera, using an Arduino and NeoPixels. I would like to just plug it into my computer, and ...
2
votes
2answers
154 views

Sending over a number from Arduino to Attiny85 [closed]

I recently started my first arduino project, displaying a number on a 4x 7 segment display. I want to keep this code and use the display in other projects to display 4 digit numbers (creating a ...
2
votes
1answer
435 views

Problem communicating between arduino UNO R3 and Mega 2560 via MAX485

I want to send data between Arduino Uno and Mega via MAX485. When I set the data Enable pin to HIGH on Mega (to transmit data) and set the same pin on UNO to LOW (to receive data) I can read data ...
2
votes
3answers
710 views

I2C Temperature Sensor Communication Issue

I'm currently learning I2C and having some issues displaying the correct temperature in the serial monitor. I am using an Arduino Uno and an SI7021 temperature sensor from Sparkfun; here's the ...
2
votes
3answers
338 views

Solution for simple multi-Arduino communication network (or alternative?)

I know similar question has already been discussed here but I could not get clear answer. Here is the thing: I have one master device - Mega2560, and multiple (about 9 but could be expandedin future) ...
2
votes
2answers
145 views

Update Variable via Arduino to Arduino I2C

I am attempting to send a simple 1 byte value from one arduino to another using I2C with the Wire library. From reading I see that this is typically done using the event monitor supplied by the Wire ...
2
votes
2answers
270 views

Can RX and TX be temporarily transposed on demand?

Only 2 arduinos can normally be linked via serial port because TX and RX need to be cross-linked, and connecting multiple TXs together would cause conflict. RS485 allows multiple nodes connected in ...
2
votes
1answer
275 views

Run code via NRF24L01+ command “dynamically”?

I'm trying to make a home automation setup but I'm having a bit of trouble. I want to be able to send commands of varying sizes to my arduino, separated by "|" and after receiving it completely it ...
2
votes
2answers
65 views

Arduino Yun receives UDP packets but prints them with gibberish

Arduino Yun is set to receive UDP packets. It receives those data with some gibberish. How is all set up: Arduino Yun (acts as a server) is connected through Ethernet to a PC which is (through WiFi) ...
2
votes
2answers
12k 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 ...
2
votes
2answers
2k views

Power Arduino with 12V while using Serial Communication over USB

I'm going to build a 8x8x8 Led RGB Cube, therefore I will need a lot of Power which the arduino can't handle, so I'm using a 12V 20A (I know 20A isn't necessary but I had one laying around). So the ...
2
votes
1answer
38 views

Simple ModBus Master function 15

I have a simple setup with arduino Nano as slave and a arduino Mega as master Can anyone explain how the function 15 FORCE_MULTIPLE_COILS Works i have been running some test on this and cant figure ...

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