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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Cannot program two arduinos at the same time because they both use the same COM port
I am not able to program my second arduino because they both use the same com port. In other words this picture says it all:
In order to upload my sketch I have to disconnect one arduino. How can I ...
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Changing the brightness on a Hitachi HD44780 LCD screen
I am finishing up a project- an LED game alarm clock. Seeing as this is a clock, I need to have a way to conserve power, which right now my Uno R3+ is eating up like a politician. My question is, how ...
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Making analog telephone calls?
How can we make the Arduino board interact with old, analog telephone, and to make phone calls?
I guess it involves connecting the board to the telephone with some specific cable (how it's called?)
...
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Does an Arduino get worn out by too much command execution?
Excuse me if it is a silly question, but I couldn't find an answer.
I've been wondering for a while whether an Arduino (or generally any other micro-controller) gets happy if the code is light and ...
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Send AT commands to ESP8266 from Arduino Uno via a SoftwareSerial port
GOAL
From Arduino UNO, send AT commands to ESP8266 via a SoftwareSerial port and receive results.
CURRENT STATUS
I either send AT commands and get nothing back (wiring scheme 1) or I send AT ...
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High precision timing on Arduino for serial communication
I am using an Arduino Uno to send time and voltage information over the serial port to Python to plot. However the interval timings between successive time stamps appears to be increasing over time, ...
- 543
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Arduino Uno R2 and Ethernet Shield R3 compatibility
I bought an Ethernet Shield R3 for my Arduino Uno R2, but since R3 has extra pins it does not fit. Can I use the shield? Should I cut off the extra pins. What do I need to do to make it work?
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Update Dynamically Tkinter Widget Scale from Arduino Ports using python and firmata
I'm having trouble trying to get Arduino digital ports values and set these values into a Python Tkinter Widget Scale.
I'm using Python and Arduino with Firmata. I'm able to access my arduino board ...
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Different ways (and the fastest) to compute sines (and cosines) in Arduino
I am using an Arduino Uno board to compute the angles of my system (robotic arm). The angles are actually 10 bit values (0 to 1023) from the ADC, using the full range of the ADC. I am only going to be ...
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Increase PWM bit resolution
I would like to increase the PWM bit resolution of the Arduino Uno.
At this moment it is 8-bit which I consider too low.
Is this possible without losing the ability of interrupts and delays?
Koen
...
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Why is my LCD 16*2 is not displaying any characters, although all the wiring is correct?
Recently I have linked up a typical 16*2 LCD (Liquid Crystal Display) display to my Arduino Uno and have linked all the pins up.
Here is my connection:(LCD pin first)
1=GND, 2=+5v, 4=11, 6=12, 11=5, ...
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3.3V, 5V and 9V pins on Arduino
On my Arduino Uno R3 and Arduino Mega R3, there are 5V and 3.3V pins.
However on this page Introduction to the Arduino Board, there is a 5V and 9V pin but no 3.3V pin. The page at Arduino: What ...
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How to call C functions from Arduino sketch?
I would like to know if there is a way to call functions that are contained within C files using an Arduino sketch?
My C file declares and defines a function. To save putting the messy function ...
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Understanding the compilation/linking/upload process (so I don't have to use the IDE)
I have started to play with and arduino UNO quite recently (without any prior experience with micro-controllers). I would like to use emacs instead of the IDE, and I'd also like to know what the IDE ...
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Powering Arduino Uno from 5V pin, what exactly is the voltage range/tolerance?
I want to bypass the onboard regulator and use the 5V pin to feed arduino with external, regulated source.
Everybody just keeps saying regulated 5V, but how precise does the regulation need to be ...
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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 ...
- 213
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How to pause Arduino for 1 millisecond through MATLAB?
I have been able to connect MATLAB to my Uno with this line of code: a = arduino('COM4'); through this package: Matlab support package for Arduino.
Right now, MATLAB is my main script that will ...
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1
answer
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I can't seem to receive data to the ArduinoStudio serial monitor on ubuntu 14.04 [closed]
I'm using the Arduino Starter Kit so I have a Uno R3 and going through the examples I'm trying to read temperature data from my controller in Arduino Studio.
In essence my problem can be reduced down ...
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How to expand program memory on an arduino?
Sometimes I run out of space of the program size for the embedded C program that I want to put on an arduino. So what chip do I need to expand the program memory of the arduino so that I can use ...
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How to move from arduino to physical prototype
I've been reading a bit about moving from Arduino to PCB and it seems a bit daunting. For now, all I really want to do is take something I've built, and make a few changes so that I can actually ...
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Reading several rotary encoders
Have an upcoming project where user input will be based on spinning a large cog and I have several UNOs available
Since rotary encoders need two pins, only a Mega would be able to handle the 7-8 ...
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Does the Arduino Uno have two crystals?
Take a look at this picture:
I think most of use agree that the "big silvery" thing on the board (red) is the famous 16 MHz crystal of the Arduino. That's what I've believed until very recently.
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Why is my real time clock getting the wrong time from my PC?
I want my real-time clock to set its time as the time on my PC. However, when I run the following sketch, the real-time clock reports the time as being 32-33 seconds earlier than my PC says the time ...
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Arduino time keeping using millis() is not accurate or correct?
I have been using the Arduino to record some data. In my Arduino sketch I also used the millis() function so I can keep track of the time at which each value I am measuring is taken. However, I ...
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What is the work of pulseIn?
I have code for an ultrasonic sensor which I found from a site. Here is the code:
#define trigPin 12
#define echoPin 13
void setup() {
Serial.begin (9600);
pinMode(trigPin, OUTPUT);
pinMode(...
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Digital Read Serial tutorial - calculating the resistor value
The Arduino Digital Read Serial tutorial guides you through the wiring of a simple button. My questions are centered around the resistor.
Why is the resistor necessary?
I think I understand this, ...
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Both red and blue led of ESP8266 stays on
I've connected ESP8266 to Arduino UNO. After a getting a huge trouble I successfully managed to run some AT commands. I have also tested AP mode.
Then I got some trouble with software serial ...
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Same structure taking different memory space on Uno and NodeMCU ESP8266, leading to data corruption when transferring via nRF24L01+
I'm trying to transfer data between a Arduino Uno board to a NodeMCU ESP8266 board, using nRF24L01+ transceivers module and RF24 library on both side. The data I'm transferring are stored in a struct ...
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Arduino interruption (on pin change)
I use the interrupt function to fill an array with values received from digitalRead().
void setup() {
Serial.begin(115200);
attachInterrupt(0, test_func, CHANGE);
}
void test_func() {
if (...
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Reasons why it is not OK to connect a relay directly from an Arduino digital pin
After looking into various schematics on controlling a relay via an Arduino, I have noticed that, most of the time, transistors are used to switch the separate supply into the relay coil rather than ...
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Only 2 decimal places in printed float
There was a similar thread before but it didn't solve my problem. I had an issue with sending GPS data, which is float, and I couldn't receive the float with the same amount of significant figures as ...
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Very long delay() possible?
I'm trying to make an opening and closing little door that should open or close every 12 hours. I was wondering if I could just make a small looping script with a delay() for 12 hours, delay(43 200 ...
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How do functions outside of void loop work?
I am used to Arduino sketches with a void setup() part that runs once, and a void loop() part that keeps looping. What happens when you have void functions outside of the main void loop()? Will these ...
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Why connect a diode between the reset pin of Arduino and 555 timer?
I am trying to create a watchdog timer using 555 IC and I am following this.
I do not understand why a 1N4148 diode is connected between the reset pin of Arduino and the output of the 555 timer.
As ...
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How can an Arduino output a specific (i.e. 56 kHz) carrier frequency?
I'm working on a free space optics project to send data wirelessly between two points. To accomplish this I'm using an IR LED connected to an Arduino Uno that pulses with a 56 kHz carrier ...
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Sending colours to vga monitor
I'm looking for a simple way to send a signal from my arduino to a vga monitor.
What would be the easiest method, and what components would be needed?
I don't need to display an image, just a ...
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Why does an Arduino UNO need two GND ports?
I have really bad eyesight, so whenever I plug in the power wire and the GND wire I always double check if I'm actually plugging in to the power port not one of the two GND ports.
Why does an ...
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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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Is it possible to program an Arduino Pro Mini using an Arduino Uno R3?
I've recently received an Arduino Pro Mini as a gift, and I don't have an external USB programmer to program the Pro Mini. However, I do own an Arduino Uno R3, and I think it would be possible because ...
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How to get current time and date in arduino without external source?
I'm working on a project using Arduino Uno and SD card shield.
I'd like to store a variable at a specific time everyday in the SD card. How can I get the current time in Arduino ?
Any help would be ...
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Servo won't stop rotating
I have an Arduino Uno R3 board and after some time not in use it seems to have corrupted. My code is below, basically I want to rotate a servo 90 degrees every 12 hours but as soon as I plug it in the ...
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Can the 2nd MCU on the UNO R3 be used for keyboard emulation?
Following on from What's the 2nd ICSP header for in Arduino Uno R3? I was wondering how this could be hacked to our advantage.
For example, could that firmware be rewritten to have the UNO ...
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What are the SVG pins for on the SainSmart Uno clone?
I bought a SainSmart clone board which is compatible with the Arduino Uno R3. Alongside each of the standard IO pins, there is a row of 3 additional pins (male). They are arranged in columns, marked S,...
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nRF24L01 pipe question
I am looking through the example code found here. I know there are 6 pipes that the nRF24L01 module can use but I've been searching the internet for the address designations and have been able to find ...
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How can a 5v Uno talk to a 3.3v Due?
I currently have an Uno (which operates at 5v), and I'm looking at buying a Due (which only operates at 3.3v). I'd like to make them communicate via Serial or SPI or similar, but presumably connecting ...
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How to send numbers to Arduino UNO via Python 3 and the module serial
I am new to Arduino (and computer programming in general), so I apologize if this question looks silly.
Once I set up a basic arduino-LED connection, I have problems sending INTEGERS to arduino ...
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Use Higher Resistance Than Instructed in a Circuit
I'm following the "Get Started with Arduino" Guidebook, and I'm at the part where pulse width modulation (PWM) is discussed.
The instructions say to create a simple circuit with a breadboard, red ...
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Arduino ADC Reference Voltage if it is Battery Powered
I am looking to possibly monitor battery power to the Arduino using its ADC. This is fairly straight forward and simple (especially if using the Arduino API); however, if the battery is powering the ...
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How can the Arduino Uno support up to 12 servos if it only has 6 digital PWM pins?
According to this:
The Servo library supports up to 12 motors on most Arduino boards and
48 on the Arduino Mega. On boards other than the Mega, use of the
library disables analogWrite() (PWM) ...
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RFID/NFC (13.56 MHz), is it possible to send raw bytes and receive response?
I'm trying to implement a card reader (i.e. credit cards) for shopping purposes, and AFAIK those cards are ISO 14443-A compliant (Mifare Classic 1K). I already made an Android app that can send custom ...