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Questions tagged [arduino-uno]

The Arduino Uno is the most common of the Arduino boards. It is based on the ATmega328P microcontroller.

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Why bootloader sizes differs from 0.5 to 8 kilo bytes for different boards?

According to official web info bootloader sizes are 0.5, 2 and 8 kilo bytes for UNO, Pro mini and ATMega2560. I believe all three boot loaders do similar job of receiving serial link data and write to ...
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Parsing JSON on the Arduino

I'm using the ArduinoJson library. There is a great example for parsing a single JSON object in the source code. I am attempting to iterate over an array of JSON objects: #include <JsonParser.h>...
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how does serial port communication work under the hood?

im just looking for how to send/ write date to pc over serial port from arduino..vice versa. I have few Question to ask after taking so much time and couldn't figure it out myself. I hope you guys ...
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LCD scrolling down problem

I have a list of set-ups and I only have 2 rows in the lcd , I'm trying to scroll down for the moment and I'm doing this by changing the row in the setcursor function to either 0 or 1. However since ...
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4answers
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Timer2 does not work as it should

I am currently playing with Arduino timers (on UNO currently) and I am building a library that has a function that must be called every millisecond. There is plenty of code samples on Internet so I ...
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1answer
186 views

cannot convert 'bool' to 'PinStatus' for argument '2' to 'void digitalWrite(pin_size_t, PinStatus) on Arduino Uno Rev 2 Wifi not working

I am a newbie to micro controllers and struggling to figure out how to fix this issue. When using an older Arduino micro controller it works fine, but when I use a new board (Arduino Uno Rev 2 Wifi) ...
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522 views

Power on reset with arduino uno can never happen. Can this be fixed?

When an Arduino Uno is powered on, the USB chip's DTR output pin may (is, in fact) low for a while. This means that the capacitor C5 is connected from the 328p reset pin to ground. Thus, when power ...
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avrdude ser_open() can't set com-state

When trying to upload the blink sketch to my (unofficial) Arduino Uno, I get the following error: avrdude ser_open() can't set com-state for "\\.\COM3" I have programmed this Arduino before using ...
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1answer
206 views

How well will the Arduino Uno survive in a vacuum?

Im doing some experiments with Pocketlab and Arduino, Vacuum will get to around -30inHg. I tried with my raspberry pi and it just kept dying everytime a vacuum was pulled. The only problem I can image ...
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Adding an LCD to Uno but not enough pins left

I am an absolute beginner and wanted to build a simple home automation system using DTMF module using this guide. My problem is out of 12 pins most of them are getting used in DTMF module(5) and the ...
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2answers
117 views

Is there any chance of fixing it?

I am new to arduino and robotic stuffs and I thought it would be a good idea to test circuits on my breadboard using arduino's R3 5V pin as power supply. The accident happened when I short circuited ...
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Why do my temperature sensor values become inconsistent when additional hardware is added to the board?

I have this strange problem. My TMP 36 sensor works fine when it is the only thing connected to my Arduino Uno board. The voltage measurements, and thus the temperature, are accurate and consistent. ...
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2answers
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Do I need 3 voltage dividers to control ESP8266

I am buying an ESP8266 and the plan is to control it serially from an Arduino. I am going to use a voltage divider(Using a voltage divider is temporary and I know the cons of using voltage dividers). ...
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1answer
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Why does an LED sometimes flash when increasing brightness?

This is admittedly a cross-post from LED fade malfunction (random flash) but I can't get an answer on the Arduino forum. I was mucking around with some very basic code and I noticed that when ...
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3answers
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Multiple GSM shields on one Arduino

I am looking for a way to listen for received text messages on multiple numbers. When I came across the Arduino and its shields, I thought to myself this might be the perfect way to do just that. One ...
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1answer
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ov7670 + Sd Card + arduino

I have three devices for making a motion activated security camera system: this is the camera : LINK OV 7670 this is the SD Card module: LINK and a basic motion Sensor: PIR with 3 pin I have an ...
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1answer
150 views

In Linux, how do I get this Arduino library to work

In Linux Fedora 20 Arduino I want to use the Timer library from here, from which I have downloaded the folder Timer-master.zip, but, when I try to import it, I get the Arduino message that it cannot ...
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417 views

How to on/off light dimmer using another pin?

In recent project, I'm working with light dimmer. Let me explain with example of fan. In switch board, we have a fan switch which can able to ON/OFF our fan & FAN REGULATOR which vary speed of ...
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Sending uint16_t over I2C

How do you transmit and read a uint16_t over I2C? I'm trying to read two uint16_t values from a slave device, and I'm seeing nonsensical readings. This is the code on my slave Arduino Uno: #include ...
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4answers
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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 ...
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1answer
13k views

Streaming audio from PC to Arduino over WiFi

Say I wanted to, purely hypothetically, set up a pirate radio station by connecting an Arduino to a WiFi network away from home, streaming music to the Arduino, decoding it, and broadcasting it with ...
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1answer
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Optocouplers for Arduino DCC decoder - Explain?

I am trying to make an Arduino circuit as outlined here. This is for connecting an Arduino input to a DCC system. DCC is a command control system for model railways that uses the same two wires for ...
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1answer
268 views

Disconnect Ethernet Shield

I'm trying to use the Ethernet Shield and the EasyVR (voice recognition) together. The Ethernet shield uses the same pins that the EasyVR, but the easyVR works fine if I don't call Ethernet.begin(). ...
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2answers
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Capturing images from OV7670 (w/o FIFO) using Arduino Uno?

I want to capture images from my OV7670 (w/o FIFO) and send it to my PC via Wi-Fi (ESP8266) (which I know how to use) using an Arduino Uno. I have read so many blogs and threads on the internet but ...
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Random(min,max) Function only giving ~50 range no matter what the values?

I can't get the min,max range to function properly. Monitoring the serial, only gives out ~50 difference from the min. I then added truerandom.ino to try to fix, but no help. const int ledPin = 13; //...
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328 views

Powering 5V Accesories

I'm using an Uno to control NeoPixels LED strips (60 per metre). These are powered with a 5V DC supply. Now, when using USB to power the Arduino it works lovely. However I want to move the Arduino ...
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1answer
140 views

Does porting code to different MCU clock frequency affect serial baud rate?

Tried to upload my Arduino Uno sketch that writes to serial UART at 9600 baud rate onto my ATtiny2313 running at 1MHz. Not getting the signal on the ATtiny, does this have to do with my clock ...
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3answers
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Bluetooth HC-05 module returns encoded data

I have searched online, and haven't found anyone hitting this issue. Strangely my Bluetooth HC-05 is returning encoded data. I have tried using different boards - Induing, Uno, Freeduino and I have ...
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1answer
2k views

How to make XBee module interrupt/wake arduino

What I am trying to do is, to have arduino in low power mode and waking up only when a packet is received and is available to be read from the buffer. A scenario : Zigbee XBee module is not ...
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1answer
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ATmega AVR frequency measurement with timer/counter

I've been rehashing some existing libraries I found on some obscure forums to measure a frequency on digital pin 5, using the ATmega328P/ATmega2560 Timer/Counter modules and an interrupt based ...
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AT command is not responding on serial monitor

I am trying to send AT commands to ESP8266. I re-flashed ESP8266 http://imgur.com/a/J8Ueh I followed this tutorial http://remotexy.com/en/help/esp8266-firmware-update/ and I hope it re-flashed ...
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Explain what is meant by “Arduino core”

What is an "Arduino core"? Are there many different "Arduino cores"? such as a core that applies to LCD displays, another core that applies to servos, etc.?
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1answer
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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 ...
5
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1answer
13k views

How to connect new OV7670 FIFO to Arduino?

I bought a new OV7670 FIFO camera to connect to my Arduino UNO a few days ago. The picture of the cam board: I found this forum, it is nice try but it looks chaotic and confusing with about 50 pages,...
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1answer
360 views

Is the Sparkfun RedBoard pre-loaded with a blink sketch?

As soon as I plugged my brand new RedBoard (Sparkfun's Uno) into my computer, I saw the onboard LED (for pin 13) blink on and off every 1 second. This was before I even sent the first demo sketch to ...
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628 views

Understanding the relationship of Pulse and Stepper RPM

This may be a better question for the Physics StackExchange so tell me if I should move the question. I have a pretty simple script that I'm using to control the RPM of my stepper motor: void loop(){...
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Arduino serial port reset in Serial monitor & Python

So am I using an Arduino with a shield to gain some voltage values for an ECG. I am then plotting that data in Python. However whenever I "observe" the serial port, be that through the Arduino serial ...
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1answer
528 views

Uno with LCD acting strangely - power issue?

I've got a Uno (Elegoo UNO R3) running with - Ethernet shield (Kuman K15), - 4 relay board (Elegoo 4 Channel DC 5V Relay Module with Optocoupler ) - Matrix Orbital 2041 LCD connected via I2C (11mA ...
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Arduino Uno as USB to Serial converter (bypass 328p)

I'm trying out computer to computer serial communication using 2 Arduino Unos (both connected to different computers). Right now, I use the Software Serial library, which redirects data from the ...
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1answer
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Get data from website with ESP8266 using AT commands

I'm trying to get data from a website by sending a HTTP GET request via AT commands for the ESP8266. Here is my current code: #include <SoftwareSerial.h> const byte rxPin = 2; const byte txPin ...
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1answer
138 views

Replacement crystal on Uno for cold temperatures

I want to run an arduino out in the cold (-40), and use the serial communication - I believe that the crystal is the weakest link (the one for the serial chip) - however I don't see any drop-in (...
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Which tft works on both Arduino Uno and Raspberry pi

Ideally I'd like a 2.8 inch and it to be touch screen. But most of all I'd rather it work on both boards without much hassle.
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How do I calibrate an ESC after connecting it to an Arduino?

I'm trying to connect an Arduino to an Electronic Speed Control and failing horribly. I'll explain what I've done so far, and then I'll explain the problem. Before we get there, here's the list of ...
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“No more addresses” when using multiple DS18B20 sensors

I want to build a scheme to get data from several DS18B20 sensors and write their temperature to serial. Before I connected them using parasite mode and using 2,7k resistor (because I didn't have 4,7k ...
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571 views

Why is my TMP35 giving me weird values?

A TMP35/36/37 is giving very high voltage readings, which results in high temperature readings. The serial monitor looks like this: As you can see, the sensor value is in the 900s, voltage is almost ...
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3answers
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Storing and parsing data with Arduino

I use Ethernet Shield and Arduino to GET data from the server in JSON format. Request looks like this: client.println("GET http://ramp.local/api/actions?"); The response I get is: [{"action_id":1,"...
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1answer
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Mechanical requirements for Arduino compatibility

If I want to design an Arduino-compatible board I guess I'll have to use the same outline, and connector positions to fit existing enclosures. (Beats me why they didn't choose a simple rectangular ...
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1answer
765 views

Simulating touchscreen input using PWM

I'm porting a project from a teensy microcontroller to the arduino. Essentially the project uses a microcontroller to simulate touchscreen input for the Nintendo 3DS console. I am doing this by ...
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1answer
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Adafruit Music Maker Shield - Retrieve song names from SD Card

I am currently working on a project that plays music for you. My question for this thread is, is it possible to retrieve the names of the songs within the micro SD card that is inserted into the ...
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1answer
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How to add the Wiring S board to Arduino IDE v.1.6.2?

My Arduino Uno is running out of memory to support my script (yes, I've tried several ways of optimize it already: PROGMEM, EEPROM, no Strings, and so on), so I would like to upload my script to my ...