Questions tagged [arduino-uno]
The Arduino Uno is the most common of the Arduino boards. It is based on the ATmega328P microcontroller.
7,774
questions
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1answer
4 views
Wind speed measuring using Hall sensor
Hi!
I require your help regarding a problem I’m encountering.
I am trying to measure wind speed using Hall sensor, Neodymium magnet & below mentioned code. But I only get “0” value for both RPM &...
2
votes
1answer
47 views
How do I run 4 LEDs sequentially based off of a push button input?
I am trying to create a program that runs 4 LEDs sequentially while also being able to do other things with different inputs and outputs. Because of this, I am using the millis function and not the ...
0
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0answers
22 views
How to implement SLAM with Arduino and stores the path memory that it has traversed by an autonomous wheeled robot [closed]
I am very much new in this field ..please bear with me .
.I am required to design autonomous robot that moves in random direction in a given area and avoids getting being hit by obstacles placed at ...
0
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0answers
25 views
Serial Connection from ESP32-Cam to Arduino [closed]
I am trying to connect my Esp32-Cam to my Arduino nano. Due to an insufficient GPIO pin on the Esp32, I used an Arduino nano. But I want to have a camera connected to my Arduino nano, and I found that ...
0
votes
1answer
24 views
7-Segment Display w/ Potentiometer
(Backstory) So, I took an computer engineering class in high school (grade 11 level), where I learned a bit about breadboarding as well as arduinos (I would like to stress a bit). It has been 5 years, ...
0
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1answer
37 views
Wiring multiple Led Displays to Arduino
I have multiple LED Displays and one Arduino and I just want to show some text on each display separately.(fps doesn't matter because there is a static text or numbers on the screen).
Is it possible ...
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0answers
26 views
MAX30102 Pulse Oximeter not working
I have recently started using Arduino Uno and wanted to make something that can measure heart rate, SpO2 etc. I have bought a MAX30102 sensor but when I connect it to the Arduino Uno, it doesn't work. ...
2
votes
1answer
81 views
Will the pro trinket gamepad library work on an Arduino Uno?
I have an Arduino Uno and I wanted to know if the pro trinket gamepad library works on an Arduino Uno since both have same atmega328p CPU chip.
1
vote
1answer
37 views
Servo keeps rotating
I used a 360° servo with a program I made on an Arduino Uno.
The program was meant to control two separate servos with two potentiometers on a breadboard. When I used 180° and 90° servos, it worked ...
0
votes
1answer
40 views
using RTC for storage
I keep seeing stuff about this: https://www.arduino.cc/reference/en/libraries/rtcvars/ when looking for storage for a few variables that survive turning off and on, but then it is only on ESP8266.
The ...
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0answers
35 views
Shortening array of numbers due to data section exceed warning
I have a sketch with 400+ GPS locations but I can't upload it to my Uno R3, I get a "data section exceeds available space in board - Global variables use 3030 bytes (147%) of dynamic memory, ...
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1answer
37 views
Can I configure an Arduino via NFC using PN532 with an iPhone as the source?
It seems clear that Apple has intentionally limited the possibilities with NFC, so I understand that I'm going against the grain here. However, I need to support Android and Apple for my device setup, ...
2
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0answers
79 views
HTTPClient works with localhost but not server
I started to work with HTTPClient and the WiFly library to connect to an SSID and then send POST data to a server. When I was sending the data to my localhost, it was working on localhost, but when ...
-1
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0answers
26 views
How can I generate interrupt with negative phase shift in Arduino UNO?
I have a 20kHz source V(source) below which I cannot control and need an output V(out) from it which is leading the source. So after the first pulse the waveforms will be as follows:
So V(out) will ...
1
vote
1answer
71 views
Whats common practice when using more components than there are pins?
I have a project where I want to use several motors (servo and stepper) which are activated with an RFID and show info on a display.
What’s common practice or a smart way to get past such limitations?
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0answers
35 views
PWM and attachInterrupts issues
I'm trying to control the speed of a DC current motor with PWM.
I use an arduino UNO to send PWM signal to a mosfet Velleman vma411 to change the average tension of a my motor which is wired to ...
0
votes
1answer
35 views
Power to triac dimmer and arduino uno
I am building 2 channel triac dimmer to control led strip lights in my pantry. Have 4 channel Krida module (just use two, I guess) and Uno. Have had some success with the triacDimmer library ...
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0answers
35 views
How to detect DTMF signal with Arduino
I'm able to detect a DTMF tone with the library https://github.com/Adrianotiger/phoneDTMF and code example:
#include <PhoneDTMF.h>
PhoneDTMF dtmf = PhoneDTMF();
void setup() {
Serial.begin(...
1
vote
1answer
50 views
Breathing LEDs on single PWM pin?
I'm doing a project which is essentially a lighted cube, that communicates status through different colors, where I get this ides [it][1] (having code). So when the light goes below a certain level it ...
-1
votes
1answer
39 views
'D1' was not declared in this scope; did you mean 'y1'?
Even though i am mentioning everything in the beginning then too m getting out of scope error. Code Reference :- https://noisycarlos.com/project/how-to-turn-your-computer-on-and-off-remotely/
I dont ...
2
votes
2answers
70 views
How to limit backlight LED current in 16x2 LCD
I'm getting the error "Current through backlight led is 23.7 kA, while maximum is 20.0 mA". What am I doing wrong?
#include <LiquidCrystal.h>
LiquidCrystal lcd(1, 2, 4, 5, 6, 7);
...
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0answers
39 views
Why can't I upload a programm to Uno R3 [duplicate]
I instaled driver and Uno is communicating with Win7 laptop via USB. But when I try to upload the Open Theremin software, after a while, I get this message:
Arduino: 1.8.19 (Windows 7), Board: "...
0
votes
1answer
30 views
How to transmit DTMF signal to Arduino
I'm trying to read an incoming DTMF signal through the A0 input pin. I want to do this programmatically and not with the MT8870 module. This library (https://github.com/Adrianotiger/phoneDTMF) is ...
1
vote
2answers
65 views
Why analogRead's value decreases when I decrease the value of resistor?(I use digitalWrite(high) to positive terminal of resistor)
Basically, my circuit contains only 1 resistor(like the basic LED circuit).
I tried to know what is the actual voltage of digitalWrite(High). I don't understand why the value of analogRead does not ...
1
vote
1answer
54 views
servo motor and l298n motor driver doesn't work together with esp32
so basically I am using 4 servo motors for our robotic arm and 1 l298n motor driver for 2 motor drive for base of the arm. when I individually tested robotic arm and controlled 4 servo motors, it ...
1
vote
0answers
31 views
I am trying to use Arduino Uno as a hid device to login Windows but I cannot use Modifier keys to Lock Windows
uint8_t buf[8] = { 0 };
#include <SPI.h>
#include <MFRC522.h> // RFID library
#define SS_PIN 10 //RX slave select
#define RST_PIN 9
int gled = 7; // optional
int rled = 4;// optional
...
0
votes
0answers
20 views
How to use the Arduino Uno as usbasp to program any AVR command line? [duplicate]
I need an usbasp which costs 365 bucks or 4 USD in my local stores.But I saw a Youtube video where a guy was teaching how we could use Arduino Uno as usbasp to program any AVR ic without usbasp. ...
1
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0answers
64 views
SMS with Uno in 2022
I'm trying to develop a simple sensor-triggered SMS message to mobile service from an Uno as a learning project in North America.
I initially thought that it might be wise to purchase a GSM/3G ...
0
votes
1answer
62 views
Why do I get different times when using analogRead() inside while loop?
I have the following code which checks the latency of another board.
int triggerPin = 13;
int dataPin = 9;
int ejectorPin = A0;
unsigned long t_start = 0;
unsigned long t_end = 0;
...
1
vote
1answer
58 views
Serial hangs on Arduino-Uno
I'm having issues with Arduino and RPI3 serial communication, it'll become unresponsive after a little time. Tried increasing BAUD rate and same issue, also happens on Windows as well so RPI is not at ...
2
votes
0answers
42 views
How I could calculate speed of a DC motor using encoder? [closed]
I am trying to calculate the speed of a DC motor using Encoder
I used these components (MG513 DC-MOTOR with Encoder, Cytron 3A 4-16V Dual Channel DC Motor Driver and arduino Uno.
When I roll the motor ...
-1
votes
2answers
62 views
How to address arbitray leds (WS2812B) in an already defined leds array?
I want to address the first and last three pixels of a 9 pixel strip and apply a gradient to them using FastLED. I can successfully address them but the colors displayed are not correct. Is there ...
0
votes
1answer
64 views
Can I use STL on an Arduino Uno?
I started using an Arduino Uno days ago. I'm an experienced C++ dev and I'm kind of confused.
Is the Arduino compiler different than a C++ one? What C++ version does Aruidno Uno use? Why it doesn't it ...
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0answers
72 views
Send/receive a hex with serial I/O board
I'm trying to get an Uno to communicate with an I/O board via serial (pins 0 & 1).
The I/O board is normally sent '00 5A 58 00 07 00 00 00 B9' to read input status. The board replies with '00 5A ...
-1
votes
1answer
62 views
i am tying to make a automated parking lot with a gate, sensor, button, keypad, how can i time how long has each car spent inside?
the project requires a automated parking lot, I have been able to connect and function the sensor and button for exit and enter, and the led(red lights when parking is full, green when there is spots)....
2
votes
1answer
51 views
How does Arduino Servo.h library manage to output PWM when a Servo motor is connected to a non-PWM pin? [duplicate]
While learning more about Servos, the main thing i have learned is that, Servos (SG90) need PWM signal with the frequency of 50Hz. And the duty cycle of the frequency is used to rotate the angle of ...
1
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0answers
35 views
Relay switch problem: Arduino Nano with a 312 PIR sensor
I am working with a 312 PIR sensor with an Arduino Uno Nano.
When sensing motion Port 13 goes High for Time_A (10 minutes). If I then press a push button on the Arduino board it takes Port D2 LOW, ...
1
vote
1answer
59 views
Blinking a led using assembly language at different frequencies using two push buttons
I want to blink a led using assembly language and arduino
I want the circuit to have a normal state of 5 hz blinking frequency
Then use two push buttons to increase or decrease the blinking frequency
...
2
votes
1answer
52 views
Doubt in coding part in blink without delay
Code 1 (here unsigned long currentmillis = millis() is in loop area):
const int LED = 2;
unsigned long previousmillis = 0 ;
const long delaytime = 1500;
int ledstate = HIGH;
void setup() {
pinMode(...
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votes
0answers
23 views
TdsValue showing over 700 ppm on plain tap water
i am a newcomer on arduino. currently trying to build an automated hydroponic solution adjuster.
the setup is comprised of ph sensor, tds sensor, thermo sensor, 4 channel 5v relay, 2 pcs of 12v relay.
...
3
votes
0answers
41 views
PCA9685 - Hardware problem with diode?
I'm working on a project, where I need to run several high-torque servos. For that I bought come of these PCA9685 boards.
I hooked everything up with my arduino and connected an external 5V - max 3A ...
2
votes
2answers
113 views
Arduino fade in/out 5 leds circuit acting wierd
I have a simple arduino project with 5 leds, the project should start with led 1 fade through 50 millisec to reach full brightness, then led 2 and so on until led 5 then turn them all off and loop.
...
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votes
1answer
62 views
How can I get an external program to change values inside the Arduino C++ code? [closed]
How can I get some constantly changing values from a separate C++ program entered and uploaded into the Arduino?
I notice when I upload code to the Arduino in the IDE it takes about a second to start ...
-1
votes
2answers
44 views
reading strings from multiple Arduinos
So I have 5 Nanos all trying to crack a password, the idea is each one has one fifth of the list so they can test 5 at a time, then when it is found, I want it to be displayed on a screen I have, the ...
0
votes
1answer
36 views
arduino 28BYJ-48 stepper only whining, not rotating
Edit, this question has been answered in the comments by chrisl, and also after retesting the code with delay() which showed I forgot to update my lastupdate variable(eerst), I have answered it in the ...
1
vote
0answers
27 views
Grove - Mech Keycap counter
I am using Grove - Mech Keycap as a counter but if I continue pressing the keycap the counter continues to run. Any idea how to program it to increase counter by one only after releasing and pressing ...
3
votes
1answer
598 views
Why do we add delay when using ultrasonic sensors?
I'm a beginner in Arduino and recently i got myself an Ultrasonic sensor (HC-SR04).
I looked up tutorials on how to measure distance with the sensor and the code I'm using is:
const int trigPin = 8;
...
0
votes
0answers
45 views
Sending an Array using nRF24L01
im currently trying to setup a wireless Controller using 2 Arduinos that communicate with 2 nRF24L01 Modules.
Unfortunately one Arduino died while testing something and therefore I can't test if the ...
1
vote
0answers
42 views
HC-05 Bluetooth module; two serial ports, COM4 and COM5
I'm learning how to use the Arduino HC-05 Bluetooth module. After pairing to it with my laptop I saw that I was getting two serial links, COM4 and COM5, as can be seen from the picture below.
On COM4 ...
3
votes
0answers
78 views
220v lightbulb gradual dimmer
I am trying to turn my incandescent bulb gradually,say its brightness should go from zero to 100% in 10 mins. In doing so I found the following code and it works well but it's not as gradual as I ...
