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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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EEPROM corrupted after complete power loss

I created a custom object that I would like to store on the EEPROM. It saves, and can be reloaded properly when I use the reset button. However, during total power loss, the EEPROM is completely ...
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1answer
34 views

Measure movement distance - not sure what sensor? [closed]

I want to measure the length of a step / stride -not sure what sensor to use. I am trying to get several people to march a pattern for a band. I am thinking a Arduino to beep when step is too ...
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0answers
35 views

Toggle switch and stepper motor

I need to connect a toggle switch to a stepper motor. This toggle switch is an On/off/on switch. In the on position, the stepper motor needs to move in the clockwise direction, in off to stop and ...
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0answers
18 views

DC motors don't stop

I'm trying to control a bluetooth car. This is my code : #include <SoftwareSerial.h> SoftwareSerial BTSerial(0, 1); // RX | TX int backFront = 3; int backBack = 2; int frontLeft = 5; int ...
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0answers
13 views

Controlling 16 LEDs using shift registers and arduino

I need to connect 16 LEDs to arduino using 2 74HC595 shift registers. A set of 8 LEDs should glow one by one towards right and another set of 8 LEDs should glow one by one towards the left. However ...
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0answers
45 views

Interrupt False triggering

Greetings of the day, i have been working with embedded systems for quite a while now, currently i am working on a project that dispenses water depending upon the balance from rfid card, however the ...
-2
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1answer
29 views

GPRS Based OTA to the NODEMCU [closed]

I need the OTA firmware update. I have the only option in my hand GSM(GPRS SIM800), with the help of this is it possible OTA, plz help me for this how I Do OTA via GPRS, FYI, I completed OTA Via WIFI.
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2answers
27 views

How do I use a servo in an interrupt?

I am working on a small circuit now where I increment the rotation of a servo motor and at the same time blink a LED. I have used all methods I know to do it but still it does not work or it blinks ...
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0answers
52 views

IR Remote used in a for statement

I’m trying to use my remote to turn on and off a strobe effect for a lighthouse that I’ve made. I can get it to turn on but not off. In the else line value > 0 was = to 0 but it would only do 1 cycle ...
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1answer
35 views

How to combine time into a variable

I have an Arduino Uno project which is recording student attendance using fingerprint sensor. So when sensor found a match, the serial monitor will be printing out Student ID and current time like ...
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1answer
44 views

Can't make ultrasonic sensor work with motor controller

I just started using Arduino Uno, I can't get the ultrasonic to work ,with motor controller board, the output value is always zero. Just to make sure I'm talking about the correct stuff: I used this ...
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1answer
85 views

Combining two code of two sensor in one program

I'm using two sensors, which is Galvanic Skin Response sensor and Heartrate sensor. The problem is that when I combined both of the codes, the only output that is showing up is from Heartrate only ...
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1answer
55 views

How to write a script if water sensor comes into contact with water for more than 2 mins and LED lights up

I am a newbie to arduino and programming. I would like to come out with a code for water sensor to detect the presence of water for more than 2mins before lighting up the LED lightbulb. Currently ...
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2answers
33 views

How to read sound sensor readings and light up sensor with water sensor if the readings is above threshold & when water is detected for 2 mins?

I am student that is new to Arduino and working on a project to trigger an alert if the sound level detected exceeds the threshold for a period of 2 mins. But I am stuck, would like to check how do I ...
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1answer
28 views

Capturing interrupt on both edges when it's set on RISING or FALLING

I've been trying to capture rising edge of an IR sensor output. This sensor's Vcc connected to Arduino 5V and it has a digital output pin. I've observed the digital output pin on an Oscilloscope. It's ...
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0answers
26 views

Not receiving data from NRF24L01

I'm trying to send data from one Arduino board to another using NRF24L01 connect to the two ends of the two Arduino boards. The Tx blinks in the transmitting end(Arduino board 1) but the receiving end(...
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2answers
32 views

expected ')' before executarAcao

here is the code: #define pinSom 7 #define pinRele1 2 #define pinRele2 3 #define tempoMaximoDeUmaPalma 150 //milisegundos #define tempoMaximoEntrePalmas 500 //milisegundos int contaPalmas = 0; long ...
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1answer
42 views

Tx Rx Arduino uno

first of all let me thank you all , you have been of great help. So, my problem is the next , i have note counter machine i need to read the data from the machine to the arduino , as bytes or ascii , ...
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1answer
39 views

Arduino baud rate 8 times too high?

I'm having a strange issue where in order to get the expected serial output on my serial monitor, I have to set the baud rate on my serial monitor to be 8 times higher than the rate that i set in my ...
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2answers
863 views

Trying to use a 7 segment display to count 0/9 with a potentiometer

im trying to switch number on the display using a potentiometer, it is just counting from 0/9. All help is much appreciated! int SegmentA = 6; int SegmentB = 7; int SegmentC = 8; int ...
0
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1answer
71 views

Controlling stepper motor direction with push buttons

I'm trying to control the direction of three 28byj-48 stepper motors using the ULN2003 drivers. I am using 6 push buttons, 2 for each motor. what I want is for each motor to be stationary by default ...
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2answers
58 views

Need some help in coding a “timer” in an if else statement

I want to code something like a "timer" (don't know what to call it) in an if else statement in my arduino uno. Basically I have 2 buttons. If the button1 is pressed and button2 is also pressed in a ...
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0answers
26 views

Send and receive SMS's

I would like to send and receive SMS's with my Arduino project. I have an A6 SIM900A GSM module with me which is from Chinese. However, it does not work and does not accept any AT commands. So, I ...
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1answer
74 views

How to convert hex to ASCII

I am receiving bytes, converting them into hex and now I need to convert the hex to ASCII. Can it be done on an Arduino? Or do I need something else? I am new to programming with Arduino.
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0answers
21 views

Note counter machine with arduino

my current project is to receive data from note counter machine to arduino , with tx, rx pins i have done some work but i am stuck , i receive hex , but i need normal chars ,and i am not 100% is hex ...
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1answer
25 views

How to concatenate a part of a string and convert then to a int?

Lets say I have String myString="AR0236"; I wish to extract the number 236 and assign it to an int. How can this be done? P.S: I'me new to programming and I tried searching the forums for similar ...
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6answers
3k views

Smaller and cheaper alternative to Arduino Uno for permanent projects

I have played a bit around with a Arduino Uno that came in a kit with a breadboard and components. Soon I would like to make some more permanent things. I would prefer a smaller and cheaper unit than ...
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3answers
65 views

Passive buzzer works with analogWrite(), but not with digitalWrite(). It also has constant static noise

I have a YL-44/MH-FMD passive piezo buzzer hooked up to an ESP8266/NodeMCU. It's connected like this: Buzzer ---> NodeMCU - GND ---> G - VCC ---> 3V - I/O ---> D2 This code makes a clear beep. ...
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votes
1answer
45 views

Communicating with a 12V device?

I'd like to connect a 12V access control device to the Arduino, but I lack the understanding. How can the signals from and to the device be done when they have different voltages? I am afraid ...
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1answer
39 views

Arduino Object Array initialization

I just got an Idea of trying to code rain simulation with arduino and Adafruit OLED display. When I finished it was quite messy code so I thought That maybe doing it Object Oriented would help. This ...
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2answers
55 views

How to burn bootloader into arduino uno without using another arduino

I need to bootload my Uno board but I do not have another Arduino at my disposal so how do I bootload without another Arduino board
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0answers
25 views

TinyGPS doesn't give longitude latitude and other data

I'm trying to get GPS coordinates using TinyGPS. But it keeps printing ********* for the data fields. Any idea on how to get this working?. Here is what the serial monitor looks like. Here is my ...
2
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1answer
53 views

How can I connect multiple different sensors that uses the same pins?

I'm doing a project on Arduino Uno and it requires me to connect 3 different sensors together: Waveshare 2.9 E-paper, MFRC522 RFID Reader and a ESP8266 wifi module. problem is, The e-paper and RFID ...
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0answers
31 views

About complementary and mahony filters

ave vector nav100 imu ,and I use raw data from 3 accelerometers,3gyros,3 magnetometers to apply complementary filter and mahony filter to get yaw pitch roll and compare these angels with angels ...
0
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1answer
74 views

Unstable analog sensor readout

I have the Arduino Uno (non-original replica) board, general SPI lcd, and GUVA-S12SD analog UV sensor module. The board (powered via USB) reads the data from the analog pin 0, converts it to voltage (...
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2answers
27 views

Won't break out of for loop

I'm new to Arduino and I'm trying to use PWM to generate a tone through a buzzer. I've created a for loop, however, the for loop doesn't seem to break when the variable ms is < 1000000. int ...
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2answers
33 views

Button state changes despite not being connected?

I have written some code to test buttons that I want to use const int buttonPin1 = 1; const int buttonPin2 = 2; const int buttonPin3 = 3; const int buttonPin4 = 4; const int buttonPin5 = 5; const ...
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2answers
59 views

Custom Classes - Redefinition of void error [closed]

I'm getting a redefinition error from my classes, but can't see what I did wrong. Error: Icon.cpp:3:6: error: redefinition of 'void Icon::setIcon(byte (*)[8])' Can any help me out on this? Thanks! ...
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votes
1answer
75 views

Connecting wires and coding in GPS Module GY-NEO6MV2 with ESP8266-01

Here is the link : https://www.circuito.io/app?components=10167,11021,12083,13678,13959,975601 I'm just a beginner I don't have the idea on how GPS module wires should be connected #include "DHT.h" #...
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2answers
57 views

Alternative Rx/Tx Pins for Arduino Uno and Pro Mini

Do they have specific pins that is best to be use as Rx/Tx pins (aside from D0 and D1)? If so, what makes them special? edit: What pin feature i should look out for when choosing the rx/tx pin? Is ...
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votes
1answer
41 views

Arduino Uno with ESP8266-01. Is that any alternative way to connect Arduino Uno to Wifi [duplicate]

I have bought an ESP8266-01 Wifi module last month, and I am trying to connect Arduino Uno to network so that I could connect to the MQTT broker. However, I failed to upload the sketch/communicate ...
0
votes
1answer
30 views

HC-05/Arduino receiving spam data

I connected everything properly. On the first try I did receive data as I was supposed to. I then wrote some logic, re-uploaded and started receiving crazy spam. My serial monitor is getting ...
2
votes
2answers
50 views

Weird behavior (Couldn't pull the pin LOW)

I was trying to implement my own code to control a stepper motor on arduino uno, however I noticed that the pins were always HIGH despite what was written to them. I started to erase the code to leave ...
0
votes
0answers
37 views

NRF24L01 code hangs at `radio.write();`

I am trying to send a constant integer value (222) from one Arduino Uno to another through NRF24L01 modules and print the received value on the serial monitor. The receiver code: #include <SPI.h&...
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votes
1answer
40 views

What makes this library work exclusively with Atmega328P boards?

I've been looking into libraries that read CPPM signals that I can use on my Arduino Pro Micro, and this one looked promising (github.com/jmparatte/CPPM) until I read that it only works on Atmega328P ...
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0answers
33 views

How to set current moved steps to current position for stepper motor?

I'm trying to code my motor working like this: Let's said the target is 2048 I programmed the motor to move 200 steps until it reach 2048 The questions is how to set the current moved steps to ...
0
votes
1answer
41 views

Unable to get output on Arduino serial communication with ESP8266 and M6E RFID reader

I am unable to get the output on NODEMCU serial. NODEMCU is connected with Arduino Uno, and Uno is connected with M6E Nano RFID reader. Currently I am unable to understand that am i doing any mistake. ...
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votes
1answer
30 views

ESP8266 is not responding to AT commands and showing mem_failed on every code [duplicate]

I was using Arduino Uno with ESP8266-12E. Today I was reading an article to blink LED using Webpage. The code wasn't uploading so I connected all the pins connected to 3.3V to 5V. Then the code was ...
0
votes
1answer
47 views

I have the code printing the data I need but don't know how to connect the data on ESP8266 IP web server

#include "DHT.h" #include "NewPing.h" #include <SoftwareSerial.h> #define DEBUG true SoftwareSerial esp8266(11,10); #define DHTPIN 2 // DHT-11 Output Pin connection #...
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votes
2answers
44 views

Connecting an Arduino to a servo with an external power supply

I have purchased an MG995 servo (4.8-7.2V operating voltage, 170MA no load operating current draw) and will power this using a 5V, 2A mains plug pack. Do I need a breadboard to connect this with my ...