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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8
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2answers
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Performance of internal vs external resistors

Is there any significant performance trade-off between buttons wired with the internal vs external pull-up/down resistors? I see a lot of tutorials demonstrating the use of external resistors when ...
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3answers
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How to increase life of EEPROM?

I want to store a few (8 as of now) IR codes into my Board's EEPROM. It would be great if someone could suggest a few tips to maximize the lifetime. The IR codes in my sketch are saved in array of ...
7
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3answers
27k views

I2C 2 way communication between Arduino Uno and Arduino Mega

If I remove the transmission code from slave this works properly but I need to transmit from slave. Here is my master code #include <Wire.h> void setup() { Wire.begin(3); Wire.onReceive(...
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8answers
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Two sensors on one input

I got this question from my teacher the other day and I can't figure it out: If you have two sensors from two different outputs but want them to go into one input, what do you need, and how can you ...
4
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3answers
711 views

powering the arduino uno

I need to power an arduino uno with a battery but for a very long period of time. And I read a lot of thing about this. Some say do not use a 9V battery with a regulator some other say that it is the ...
3
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1answer
14k views

Modbus RTU controller monitoring with arduino and RS485 module

I'm a medium user in Arduino. I baught a pHmeter controller with RS485 output (MODBUS RTU protocol). I want to get pH value read by the controller over RS485 module and Arduino. According the ...
3
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1answer
2k views

Arduino with ESP8266

I have completed the circuit and code to interface ESP8266 module with Arduino UNO. When i send AT,AT+RST from serial monitor the reply is correct . But when i send AT commands to search WIFI ...
2
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2answers
18k views

Arduino: Read frequency of input from audio jack

I want to trigger an arduino from a sound from an audio jack from a mobile phone. The audio is a 1 Khz sound that the mobile will play. I want to avoid accidental triggering of the audio by testing ...
2
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2answers
59 views

Change the fuses of an Arduino Uno (can an Arduino Uno change its own fuses?)

For now, I'm using an Arduino Uno alone including its 328p (no other external chip to program). I would like to change its fuses to internal 8 Mhz clock (because then I'll move the 328p out of the ...
2
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2answers
16k views

avrdude: ser_open(): can't open device “\\.\COM3”? [closed]

My computer cannot detect my Arduino Uno anymore, Reset button- > L led light blinks and it turns on forever Arduino 1.6.5: Tools->Port (greyed out) I remembered that previously it wasn't like this ...
1
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1answer
6k views

Implementing DES or AES Encryption with DateTime Synchronization on Uno

We are trying to implement AES or DES encryption using an Arduino Uno. We have a keypad module attached that will be used to input integers. A String should be generated based on the entered data and ...
1
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2answers
10k views

Send multiple int values from Python to Arduino using pySerial

I'm trying to send 3 ints in the range of 0-180 from Python to the Arduino Uno device using pySerial (py3K). I have managed to send 1 int by using python's struct lib (not sure if it's the best or ...
1
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1answer
7k views

DHT11 data in Arduino UNO to Firebase through ESP8266

Hello Good Day to Everyone. I have a project where I need to send DHT11 sensor data to a Firebase database using both Arduino UNO and Esp8266 esp-01 wifi module. Both of them must work together to ...
0
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1answer
4k views

How to connect Arduino device to Linux?

I wrote Arduino sketch and it works. It waits for a command and answers text on response. Simultaneously, I can't get any response with command line tools. For example, I have the following code to ...
0
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1answer
6k views

Differences between a real and clone Arduino uno?

Today I got my clone Arduino and connected it to my real Arduino and they both work. (UPDATE: The Arduino noted as real Arduino probably also is not a real Arduino; however both work fine). However, ...
20
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2answers
23k views

Why do some pins have a different PWM frequency?

According to the Arduino reference for analogWrite(), the PWM frequency on most pins is ~490 Hz. However, it's ~980 Hz for pins 5 and 6 on the Uno, and for pins 3 and 11 on the Leonardo. Why are ...
14
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5answers
4k views

How to connect two Arduino without shields?

I'm planning an Arduino system that consists of several Arduino boards. The maximum distance between the boards is about 50 meters. I want to send basic data between these, like short strings or ...
9
votes
3answers
73k views

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, ...
9
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1answer
3k views

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 ...
7
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1answer
9k views

Increasing payload size above 32 bytes using nRF24L01+

I tried to modify the example in the following page, by replacing the given string with a 56 bytes one after making all the suitable changes to read(), write() and max_payload_size(increased to 64 ...
6
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1answer
527 views

Choosing right Sleep state

I'm planning on building an LED clock, but I want it to be lit only when I press the POWER button on my remote control. Using an IR receiver, which Arduino sleep mode should I use to reduce the ...
5
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3answers
3k views

Make Sure \n is the last character in serial string

I have an Arduino that I've put between a computer and an RS485 device. The job of the Arduino now is just to transmit data but will eventually do data logging and have a small user interface as time ...
5
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3answers
2k views

Can't upload to my Nano after updating to Arduino AVR Boards 1.6.21

I recently had the Arduino IDE notify me of available boards updates, so I updated. Since then when I try to upload to my Nanos it fails: avrdude: stk500_recv(): programmer is not responding avrdude: ...
4
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4answers
2k views

Rotary encoder on Uno and interrupts issue

This question is regarding a project using an Arduino Uno. I have one of these quadrature rotary encoders. I'm using a slightly modified version of the code from the article, Quadrature Encoder too ...
4
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3answers
1k views

Moving motion sensor?

Long story short, I'm trying to build some form of device that you can wear and it will detect when something moves behind you. I wanted to use PIR sensors for the motion detection, but I have no idea ...
3
votes
1answer
317 views

How does one design for the power on transient conditions?

Following on from the question Reset an Arduino UNO by an command (software) and the excellent answer provided by mpflaga, the comment addressing option (1) suggests that there are design ...
3
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1answer
6k views

How to generate hardware interrupt in mpu6050 to wakeup arduino from SLEEP_MODE_PWR_DOWN mode?

I am using Arduino UNO and has kept in SLEEP_MODE_PWR_DOWN mode & want it to wakeup using MPU6050 hardware INT pin (which should send a signal when MPU is in motion). I have used the article https:...
3
votes
1answer
4k views

Arduino with WS2812 using Adafruit NeoPixel library fade in/out different patterns

Hey all I have been trying to figure out a way to random set patterns for my fade in/ out code below: int PIN = 3; int totalLEDs = 11; int ledFadeTime = 5; Adafruit_NeoPixel strip = ...
3
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1answer
76 views

Project structure to build for PC and Arduino

Recently I have started developing for Arduino Uno. I have 10 years experience in software development (C#, Delphi), but not much with C/C++. Compiling the Arduino sketches seems a little slow, and ...
3
votes
2answers
25k views

How to control 19 RGB LED strips with one arduino?

I need to light up 19 RGB LED strips, which it seems would require 19*3=57 PWM outs and 57 transistors. The transistors aren't an issue, but of course the 57 PWM's is. Even if I hacked the digital ...
3
votes
3answers
13k views

Using external power supply to power leds on multiple pins (A0-A5)

I'm totally new to Arduino, and microcontrollers for that matter, so I'm having a hard time figuring out how to connect LEDs to multiple pins, but using a common external power supply... I've created ...
2
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1answer
2k views

Using the Waspmote Sensor Board

Spanish company Libelium makes this pretty impressive sensor board: http://www.libelium.com/products/waspmote/sensors/ for their Waspmote series of boards. These are not meant for Arduino ...
2
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3answers
5k views

Storing an array of function pointers

I have some Arduino code that looks like: char packet = ser.read(); switch(packet){ case 'a': someobj.somefunc(); break; case 'b': otherobj.otherfunc(); ...
2
votes
1answer
126 views

Powering an Arduino UNO through 5V

I have a bench supply which I can use to power a breadboard at 5 V. Is it a bad idea to power the the Arduino by going directly to the 5 V pin? It sounds like both this method, and the USB are ...
2
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2answers
601 views

Is my Arduino dead?

I connected my Arduino Uno to an external power supply, but did not noticed the power supply was on 30 V, I saw the part in the picture smoking and immediately pulled the cable out of the Arduino....
2
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3answers
3k views

Negative voltage: How do I scale a 0 to 5 V signal to -10 V to +10 V?

To control my robot, I need to generate negative and positive voltage in a single line, because the motor I try to control is an industrial one. Do you have any suggestion for it? How can I produce a ...
2
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3answers
15k views

Detecting if a push button was pressed and released

I want to detect if a push button was pressed and released again. So I thought the right approach would be to first wait while the pin yields LOW and then wait while the pin yields HIGH: void push(...
2
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3answers
1k views

Arduino starter kit servo is shaking

In the example of the arduino starter kit the point is to use a potenciometer to control a servo. The code is angle = map(potVal, 0, 1023, 0, 179); The output in the serial potVal: 1023, angle: ...
2
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1answer
2k views

Arduino and WS2812 RGB LED Strip “freezing”

I have been working on a project as a gift for my girlfriend for Christmas which involves some a bunch of standard "white" LEDs controlled by shift registers and darlington arrays, and also some RGB ...
2
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2answers
549 views

Problem with measuring vibrations (Arduino UNO + step motor + accelerometer)

I'm trying to measure vibrations of the motor's shaft that is oscillating due to an eccentric load. For that, I am using the MPU 6050 6 axis accelerometer. The motor is a NEMA 17 stepper, connected to ...
2
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1answer
408 views

Understanding Digital IMU 6DOF sketch

I am looking at the following code and getting confused by a few elements in it: 1) Why is there a writeto function being performed to the memory locations x053,0x31,x09 for accelerometer and 0x68,...
2
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2answers
879 views

Breadboard Arduino not loading sketches

I have put together a breadboard version of the arduino by following the tutorial on arduino's main website https://www.arduino.cc/en/Main/Standalone. I have done everything exactly how that tutorial ...
1
vote
1answer
9k views

Send JSON via POST on SIM900 shield with AT commands

I'm trying to send a JSON POST in SIM900 shield with AT commands. After I call the AT+HTTPACTION=1 command, it returns a 601 error: +HTTPACTION:1,601,0. I saw here that the error was 601 Network ...
1
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2answers
3k views

DB:NO RESP Using inet.httpPOST on loop()

I'm using SIM900 module + arduino uno + gsmlib.org library. I'd like to send a string to endpoint on my API , and it worked correctly for the first time when I using inet.httpPOST function in setup(),...
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2answers
8k views

Arduino Uno vs Arduino Micro timers → pins

Where do I find the pins relative to timers of each individual Arduino microcontroller? As I like Arduino's I already have various samples of them. The one I mostly use is the Uno and Micro for now......
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3answers
2k views

How to use an Arduino Uno + Keyboard Firmware to make a “N Key Rollover” Game Pad

Hello I have flashed my Arduino Uno with USB keyboard firmware from this tutorial http://mitchtech.net/arduino-usb-hid-keyboard/#comment-6786, and I have been successful sending individual key presses ...
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3answers
2k views

Synchronization and Implementing hamming code on Software Serial

I want to learn and use Hamming Code. Would it be wise to alter the Software serial library to do this or just change the data being transmitted in the actual Arduino sketch? Also, for means of ...
1
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2answers
447 views

On the Uno, why does VIN require 7-12 volts and the USB only 5 volts?

I'm just wondering why the VIN would require 7-12 volts when the USB port itself only requires 5 volts? What happens if you power an Uno on VIN with 5 volts?
1
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1answer
868 views

(Neopixels) How to keep the pixels of the same colour despite increasing brightness?

I've been doing a fade function for the NeoPixels. However, the moment I have maximum brightness for the pixels, I noticed there 2 colours even though in my function I have only specified one colour. ...
1
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3answers
18k views

How to convert an hex string to an array of bytes?

How to convert the char array to Byte array? I tried every method but it doesn't work. char CardNumber[8] = "B763AB23"; // Length is 8, basically it's in Hex // B7 63 ...