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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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7
votes
1answer
15k views

The difference between “time_t” and “DateTime”

I've run into an issue trying to combine 2 different Arduino timer projects I've found online. For both projects I'm using a DS3231 RTC, but have been able use the DS1307 library just fine in my ...
7
votes
1answer
283 views

What is the physical location of the U1A symbol on Arduino Uno?

I'm trying to find an easy way to allow an Arduino Uno to determine if it's being powered from USB or the DC barrel jack. In this thread, one user recommends wiring the output of the on-board ...
7
votes
1answer
2k views

What good designs are available for Geiger counters using an Arduino?

Are there any good circuit designs for Geiger-counter projects using an Arduino? If so, what Geiger-Muller tubes should I choose to detect different types of radiation?
7
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2answers
2k views

Programming Chinese Arduinos

I have an authentic Arduino UNO, but I didn't want to pay full price for a new one to build semi perminate projects, so I bought a few ATMEGA328P-PU chips off of AliExpress: https://www.aliexpress....
7
votes
3answers
5k views

Can I use arduino's 3.3 V output directly to esp8266?

I just bought esp8266 and ftdi usb driver, I want to power the esp8266 with Arduino's 3.3 V output, is that possible? I saw some tutorial on youtube in that they are suggesting us to use 3.3v ...
7
votes
2answers
803 views

Using Arduino for simultaneous lighting effects

I am building a computer for my son (me). I'm trying to spark his interest in computer technology, so my idea is to drive multiple case lighting effects with a microprocessor or controller. I went ...
7
votes
1answer
1k views

Hooking up LCD screens reclaimed from old camcorders to Arduino [closed]

Has anyone had any luck using LCD screens reclaimed from old electronics with Arduino, such as camcorders etc? My 8 yr old has an old sony handycam (dcr-trv103) in bits and now wants to use the LCD ...
7
votes
3answers
6k views

softwareserial between arduino uno and esp8266

I have an Arduino UNO and HUZZAH ESP8266 module. I need to send data between Arduino UNO and ESP module via Software Serial. Right now I have the ESP module write data and Arduino UNO display data, ...
7
votes
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(...
7
votes
1answer
14k views

How to build (concat) a string with big numbers

new to arduino I'm struggling with what sounds like fairly n00b problem... I've wired up a adafruit GPS-board to my Arduino and it is working as it spits out GPS data to the serial port with Serial....
7
votes
2answers
3k views

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 ...
7
votes
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 ...
7
votes
2answers
919 views

Is there a pullup on I2C?

I am using an Arduino Uno R3. It is not clear on the schematic whether there are pullups on the A4 and A5 I2C pins. Are there hardwired pullups or do I have to add them myself?
7
votes
1answer
1k views

Arduino Servo won't move when using classes

I'm trying to make a class work with Arduino, however it doesn't seem to trigger properly. The code is compiling perfectly, and it's supposed to control the leg of an hexapod. Also, the example sweep ...
7
votes
1answer
3k views

Why does increasing resistance make a capacitive sensor more sensitive?

From the Capacitive Sensor Page on the Arduino website, it states the following: The capacitiveSensor method toggles a microcontroller send pin to a new state and then waits for the receive pin to ...
7
votes
1answer
3k views

RTClib library dependency on Wire library

I downloaded the RTClib library from https://github.com/adafruit/RTClib. In every provided example, #include <Wire.h> is written immediately above #include "RTClib.h" at the top of the sketch. ...
7
votes
1answer
3k views

Arduino as a real device to computer

Suppose we have a computer mouse , now when we connect it to a computer then computer understands it is a mouse which is been connected to it. Same thing happens for keyboard and many other devices. ...
7
votes
6answers
2k views

Fluctuating readings of LM35 temperature sensor (+- 5°C) with Arduino UNO

I am trying to read a LM35 temperature sensor with Arduino UNO which I got as a gift. The issue is the fact, that my readings of sensor are, well, suspicious at least - they jump with each reading ...
6
votes
4answers
616 views

Programming standalone Atmega328p-PU with NE555N timer IC

I know I may sound a little idiotic to ask, but as I have seen in the internet that to program a standalone Atmel chip like that from of the Arduino's, you need 2 22pF ceramic capacitors and a 16mhz ...
6
votes
3answers
29k views

Arduino outputs garbage values on serial monitor with ESP8266

I have connected my Arduino with an ESP8266. When I check the ESP8266, by manually entering commands at serial monitor, I get correct results. However, when I run this program #include<...
6
votes
2answers
1k views

Simple multiplication bug

Executing the following code always gives -511 as a result, I performed many tests, and it seems that results are correct from 0 * 0 to 181 * 181, beyond that, results are abnormal, I tried many types ...
6
votes
2answers
7k views

What is actually an IC (Integrated Circuit)?

They say that you must know what IC your board has before loading a new program from the Arduino IDE and that the information is available on the top of the IC, but where is it exactly and what is an ...
6
votes
2answers
3k views

Source code for Arduino “firmware”?

I am wondering if anyone here knows where the source code for the Arduino "firmware" is available for reading? I think it must be more than the 'boot loader' but I am not sure. Thanks! p.s. I assume ...
6
votes
5answers
30k views

Can I measure velocity from an accelerometer? How accurately?

I've bought this module Kootek GY-521 MPU-6050 MPU6050 Module 3 Axis analog gyro sensors+ 3 Axis Accelerometer Module My project will involve affixing this to a moving object, moving at velocities ...
6
votes
1answer
4k views

How to stop uno from running program when powered on?

Does anyone know how to prevent the Uno from running the last program when it's powered on? Many times I have changed hardware and wiring without clearing the program first. Then when I power it on ...
6
votes
2answers
1k views

Why is my SRAM so quickly filled? There are not more than 60 bytes

I have just gone through all my code. At max I use 60 bytes. I have done everything in order to minimize its usage - I even store booleans as bits, not bytes! What could be happening here? The only ...
6
votes
3answers
6k views

How do I update the serial monitor without printing a new line each time?

I'm testing out an accelerometer and I want to know if there's a way to make it so that the serial monitor will update the values without printing a new line. Ideally the serial monitor would say ...
6
votes
2answers
3k views

What is the rise time of an output pin of atmega328 changing its state?

I've already searched a lot and didn't found the answer. Also, I don't have an o'scope. Anyone can help me?
6
votes
5answers
32k views

Inappropriate ioctl for device

I am using an Arduino Uno and a Mac and trying to upload my code into the board. I tried uploading the program from different computers(MacBook Air and Pro) and I still have this problem. How do I ...
6
votes
2answers
6k views

bootloader uploading into Atmega328

Here is mine circuit. Intially i used arduino UNO directly for programming. Now i am Using atmega 328 IC for programming. I am trying to connect 32 hall sensor via Mux circut. I wanted to How to ...
6
votes
2answers
9k views

“Broken Pipe” when uploading to Arduino UNO

I just got my Arduino UNO and I'm trying to upload the blink example but the upload fails with ioctl("TIOCMSET"): Broken pipe ioctl("TIOCMSET"): Broken pipe avrdude: stk500_recv(): programmer is not ...
6
votes
1answer
4k views

Warning Arduino CMakeLists “Policy CMP0022 is not set: INTERFACE_LINK_LIBRARIES”

I'm trying to build an Arduino example without using its IDE. My OS is Windows 8.1 and I'm using the last version of CMake (2.8.12.2) and MinGW (GNU Make 3.82.90). I downloaded the Arduino ...
6
votes
1answer
4k views

How to use RS-232 sheild as software serial port?

I would like to be able to use a USB port at the same time as an RS-232 port with my Arduino Uno board. I unwittingly bought a shield that (I think?) overrides the USB port when it is mounted to the ...
6
votes
2answers
547 views

Webserver on Arduino

How can I run a webserver in a Arduino Uno? I want to use my Arduino to monitor things in my home such as temperature. I want to be able to access this data through the internet.
6
votes
2answers
11k views

How to connect an Arduino to WIFI using an ESP8266

Hi I am trying to make Arduino Uno on local network with the help of ESP8266 wifi module. I tried to search on internet, found mostly they are making ESP8266 as web server.http://circuits4you.com/...
6
votes
2answers
48k views

Sending and receiving different types of data via I2C in Arduino

I have found a few good tutorials on how to send and receive data via I2C in connected arduinos. My limitation is now how to transmit different types of data like for instance, long, float, etc. Right ...
6
votes
2answers
201 views

Disturbed digital out at 4Mhz on Arduino NANO

I've written a simple program - it generates signals over Port D at 4 MHz: #include <Arduino.h> int main(void) { DDRD = B11111111; PORTD = B00000000; while (true) { PORTD ...
6
votes
1answer
1k views

Sending MIDI messages using PING ultrasonic sensor

I am working on a project that uses a potentiometer and an ultrasonic sensor to create MIDI signals. This is my first time working with an arduino. I took a class in C++, but am teaching myself some C ...
6
votes
3answers
19k views

How to reset ATmega328P fuses using USBasp programmer?

I think I bricked two ATmega328Ps when I was trying to burn new bootloaders using Arduino Pro Mini, the USBasp programmer and the Extreme Burner AVR software. I had two ATMega328p with bad booloaders ...
6
votes
2answers
2k views

How to measure voltage with Arduino analog input

I'm totally new to Arduino and to electrodynamics in general. I'm wondering what happens if I connect my digital pin to an analog input on Arduino, and make digitalWrite and analogRead on the ...
6
votes
5answers
9k views

Simultanous read and read/write on two serial connections

At the moment I'm using two softserials to connect to a GPS and an GSM module. It seems not possible to have two open software-serials. So I was looking for an solution After the initial-setup, the ...
6
votes
5answers
8k views

My Servo Won't Sweep Smoothly

So I've tried this a few times and I always get the same issue. When I try to run the sweep example the servo goes round 180 degrees but only in steps. Anyone know a way to fix this? The servo I'm ...
6
votes
1answer
558 views

Problems with transmission between ATtiny85 and Arduino Uno with 433MHz RF modules and Manchester

I am trying to transmit from an ATtiny85 running at 16MHz internal clock to an Arduino Uno with the Manchester Library. The problem is that the Arduino is not receiving any data. I have hooked an ...
6
votes
1answer
269 views

Why does pulse sensor shows gaps when I move it?

I modified the serial code in this way and I don't think the gap is produced by my edit even because it made it even before: ////////// ///////// All Serial Handling Code, ///////// It's ...
6
votes
2answers
8k views

arduino creates strange files in SD card

I'm new to Arduino and electronics. I want to make a project including SD data-logger, but I had a problem. I would appreciate if someone show me where I made a mistake. Firstly, circuit was set up ...
6
votes
1answer
2k views

Level tracking using optical or capacitance sensors

I am looking to devise a level tracking system using arduino and some sensors. My particular situation is I have solute that is coming out of solution and I want to track the formation rate of the ...
6
votes
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
votes
7answers
4k views

Can Arduino control 8 solenoids?

I know very little about Arduino and even less about programming one. Before I purchase a board, and learn how to program it, I was wondering if my idea is feasible. I want to program the Arduino to ...
5
votes
4answers
24k views

What purpose does the yellow and green LEDs have on the Arduino?

I have wired up a small project with a shift register (see below), but depending on how I put the 74HC595 IC (8-bit shift register with 3-state output register), the green and yellow LEDs of the ...
5
votes
4answers
3k views

Can the Arduino Uno become an AVR programmer and use the ICSP header to program the target board

The Arduino Uno has an ICSP header that I imagine is for programming the board using a separate ICSP programmer. That is, its ICSP header turn the board into a target. Can one use that same ICSP to ...