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Questions tagged [arduino-uno]

The Arduino Uno is a microcontroller board based on the ATmega328 and created by Massimo Banzi.

The Arduino Uno is a microcontroller board based on the ATmega328 and created by Massimo Banzi. It has 14 digital input/output pins (of which 6 can be used as PWM outputs), 6 analog inputs, a 16 MHz ceramic resonator, a USB connection, a power jack, an ICSP header, and a reset button. It contains everything needed to support the microcontroller; simply connect it to a computer with a USB cable or power it with a AC-to-DC adapter or battery to get started.

The Uno differs from all preceding boards in that it does not use the FTDI USB-to-serial driver chip. Instead, it features the Atmega16U2 (Atmega8U2 up to version R2) programmed as a USB-to-serial converter.

Revision 2 of the Uno board has a resistor pulling the 8U2 HWB line to ground, making it easier to put into DFU mode.

Revision 3 of the board has the following new features:

  • 1.0 pinout: added SDA and SCL pins that are near to the AREF pin and two other new pins placed near to the RESET pin, the IOREF that allow the shields to adapt to the voltage provided from the board. In future, shields will be compatible with both the board that uses the AVR, which operates with 5V and with the Arduino Due that operates with 3.3V. The second one is a not connected pin, that is reserved for future purposes.
  • Stronger RESET circuit.
  • Atmega 16U2 replace the 8U2.

"Uno" means one in Italian and is named to mark the upcoming release of Arduino 1.0. The Uno and version 1.0 will be the reference versions of Arduino, moving forward. The Uno is the latest in a series of USB Arduino boards, and the reference model for the Arduino platform; for a comparison with previous versions, see the index of Arduino boards.

Quick summary

Microcontroller               ATmega328
Operating Voltage             5V
Input Voltage (recommended)   7-12V
Input Voltage (limits)        6-20V
Digital I/O Pins             14 (of which 6 provide PWM output)
Analog Input Pins             6
DC Current per I/O Pin       40 mA
DC Current for 3.3V Pin      50 mA
Flash Memory                 32 KB (ATmega328) of which 0.5 KB used by bootloader
SRAM                          2 KB (ATmega328)
EEPROM                        1 KB (ATmega328)
Clock Speed                  16 MHz

Detailed specifications: http://arduino.cc/en/Main/arduinoBoardUno#.Uyqh84X-tqc

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Arduino can't output in both led screen and serial monitor at the same time

I am trying to have Arduino output on both LED screen using the LiquidCrystal library, and on Serial Monitor (later to a txt file or something like that). In my code, I commented out Serial.begin(9600) and then the screen outputs correctly, but as…
J.C
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Arduino RPM code with Quadrature Encoder 600ppr

I'm attempting to setup my arduino uno in such a way as that it provides me with the RPM being measured on my encoder. So far I have been able to figure out how to accurately measure the RPM for the first value, however I am struggling to reset the…
Allan Bonet
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Stepper motor speed control by Arduino

I'm building a little project to move the stepper motor according to the time the person keeps the switch pressed, and the longer the time, higher the speed. The code I'm using increases the speed and I can see it at Serial Monitor, but the stepper…
Pedro_Galahad
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PyModbus RTU response received even if there is no connection

I'm using PyModbus on Linkit MK7688 that is connected to Arduino UNO using MAX485. Following is my code for writing to coil. from pymodbus.client.sync import ModbusSerialClient as ModbusClient import logging FORMAT = ('%(asctime)-15s…
prashant
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at command not responding on sim800L and arduino uno

I would like to ask around SIM800L EVB module to sending message using Arduino UNO R3 DIP/SMD CH340. i change the pin tx/rx from 2, 3 vice versa, 7,8 the result either not displaying anything or anytext, the serial monitor just displaying AT no…
mogleng
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Light Sensor Assembler in Arduino

I am doing a home automation project with an Ardoino UNO. I need to use a light sensor, however since in assembly there is no analogRead function (), I have to program it. I already read the documentation of AVRand Atmel about the ADC, the MUX and…
AleBerto56
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Issue with FastLED and a simple counter

Okay, I'm having one baffling issue with this code. The counter pushCounterz (named with a z only to rule out a conflicting variable) will start with the correct counter (1 or 0 or whichever) and one of a few things will happen when the button is…
Beeker
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How to read data from arduino in python without showing b' SOMETEXT \r\n'

Using python3 and pyserial on a virtualmachine ,Ubuntu 17.10, Ran the code like this "User@user:$ python3 ardui.py". I'm trying to get rid of the b' ... /r/n' just get text or string for example , I get this on python b' What's 9+10? /r/n' but Im…
papisilv
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Setting up Arduino Uno (ATMEGA328P) PWM with Timer1

I want to setup a custom frequency(12Hz) and duty cycle (20%) with a 16MHz Arduino Uno (ATMEGA328P). AVR Calculator yields: ICR1 = 20833 OCR1A = 4167 I have read a tonne of forums and tuts but for some reason I cannot get this to work. Below is my…
Dylan144GT
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Why doesn't the LED turn off?

I have a program (copied below) that has an alarm that starts in 10 seconds, which starts a LED that blinks every two seconds. I would like to push a button that turns off the alarm / LED. The LED blinks as intended but does not turn off when I push…
Ronnie L
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pySerial sending and receiving multiple data

I have a question about sending and receiving multiple data using the pySerial Python library. According to what I understand, serial port communication works with byte variables. How do I send four different variables with method write and then…
Henry Avery
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Save a fingerprint to the database of the fingerprint sensor

I'm using the Adafruit Kookye fingerprint module in my project. Since it can only allocate 256 fingerprints I need to make a program to free the memory and add additional users. I have made the following function at the library: uint8_t…
Ricard
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How to get Arduino to read serial from Python?

Specific problem I am trying to communicate between a Python script and my Arduino Pro Mini using serial with a USB cable. In Python I can read what the Arduino writes but the Arduino can either not read what the Python writes or it is reading it in…
chkrs888.
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Node JS serialport@6.0.0 Opening port and closing it automatically

I'm using Node JS SerialPort@6.0.0 Package for connecting to computer ports. I wrote this code to get the arduino-uno data: const SerialPort = require('serialport'); const port = new SerialPort('COM4',{ baudRate: 9600 }); port.on('open',…
Fabricio Cerci
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GSM SIM 900A Wont send a Message Using Arduino UNO

My Connections are 5VT to D9 5VR to D10 And external adaptor for power.. (5v 2A) The blinks are good because it blinks every 3seconds, The sim card is loaded. But when I run the serial monitor, It only shows AT AT AT sometimes AT with reverse…
Charles Galvez
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