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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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37 views

PWM Control, How to stop LED from Flickering?

What is required is controlling the brightness of an LED using both Buttons and a Potentiometer, Button A: Increase Button B: Decrease /Dim Potentiometer: Increase and Decrease, This however must ...
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1answer
42 views

Question about a code

This code is used to toggle an arduino on and off , the problem is that i can't comprehend it at all. can someone explain to me how does it work ? New = digitalRead(button); if ( New!=old) { ...
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1answer
45 views

Wanted to control 2 servos with serial read [closed]

I want to use 2nd servo only when 1st is in up state by asking user whether he wants to fire or not.(code in bold is not working ) #include <Servo.h> Servo myservo; Servo trigervo; ...
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1answer
42 views

Problem with arduino starter kit project 7

Can someone pls help me only the two buttons clossest to the big green wire work and i don^t know why i have already tried swapping buttons EDIT 1: my code and i know the first two are working ...
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1answer
33 views

How do I know if GY-521 MPU6050 has been calibrated properly?

I am planning to use the accelerometer of MPU6050 for a project. I know that before using module (I am using GY-521 MPU6050), one needs to calibrate it. I am using code by Luis Rodenas for ...
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1answer
50 views

White screen when I perform grapicstest in ili9341

I get a white screen when I perform grapicstest in ili9341. I used the below code: #include "SPI.h" #include "Adafruit_GFX.h" #include "Adafruit_ILI9341.h" // For the Adafruit shield, these are the ...
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1answer
45 views

ESP8266 HTTPS post body request with WifiClientSecure

Is there a way to post HTTPS body request in Arduino esp8266. I am able to HTTPS parameter request with WifiClientSecure library,but is not safe compared to Request Body send in POST.
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0answers
33 views

Code stuck on mag.getEvent(&event); in HMC5833L Compass

Last week I created some code in which I can run a Ublox GPS NEO-6 and a magnetometer HMC5883L together. Which at the time worked brilliantly. Yesterday I have attempted to run the code again, with ...
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2answers
37 views

Arduino uno holder

Arduino sells a holder for the UNO board, but without much documentation or detailed specifications, see this link. Can anyone give the diameter of four small holes, two located on the top edge and ...
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0answers
28 views

Interfacing Uno to Logitech Attack3 Joystick

I bought a Logitech Attack3 joystick at a garage sale for a couple of bucks and now I want to use it for something useful, like controlling a car or my small robotic arm. This joystick has 11 buttons ...
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0answers
25 views

exit status 1, cant compile , please help

/*************************************************** This is our GFX example for the Adafruit ILI9341 Breakout and Shield ----> http://www.adafruit.com/products/1651 Check out the links ...
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1answer
18 views

Burning Arduino Bootloader

I'm trying to use an atmega chip from an arduino on a breadboard, with minimal hardware (using the internal 8mhz clock). I am using the article in the link provided. When I reach the final step (...
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0answers
28 views

Problem in integrating speed sensor LM393 with L298N

I am currently working on a project that has an automatic support wheel for bicycle. The mechanism of this project is when the speed sensor is detecting the RPM of the rear bicycle wheel it will ...
1
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1answer
49 views

Measure cycle count and time of Digital Input

I am currently working on a project which is read a digital input signal from a machine. The machine operation is as below: when the mold close, the machine gives the "HIGH" signal, when mold is open ...
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2answers
120 views

expected `}' at end of input

int scvVal = 6; int drvVal = 9; int sensorVal = A1; void setup() { Serial.begin(9600); pinMode(6, OUTPUT); pinMode(9, OUTPUT); } void loop(){ sensorVal = analogRead(A1); Serial....
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4answers
674 views

changing state of an LED using a pushbutton leads to unstable result

I am trying to run this code: const int buttonPin = 7; const int ledPin13 = 13; int buttonState = 0; int lastButtonState = buttonState; bool flag = true; void setup() { // ...
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0answers
18 views

empty message receive

#include <GSMSim.h> #include <SoftwareSerial.h> #define RX 7 #define TX 8 #define RESET 13 #define BAUD 9600 GSMSim gsm(RX, TX, RESET); const int doorSensor= 2; int doorSensorState= 0; ...
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0answers
14 views

Bluetooth not Transmitting over HC05 Master Slave Setup [duplicate]

I am trying to control a robot, where I have one HC05 module as a master connected to an Arduino Uno with an attached joystick. This Arduino sends data signals that will run blocks of code on the ...
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2answers
41 views

problem in uploading the code [duplicate]

Arduino: 1.8.9 (Windows Store 1.8.21.0) (Windows 10), Board: "Arduino/Genuino Uno" Sketch uses 12452 bytes (38%) of program storage space. Maximum is 32256 bytes. Global variables use 970 bytes (47%) ...
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1answer
45 views

Calculating the time between the signal when its ON and when it gets OFF

class Channel { private: uint8_t _pin; uint8_t _state; uint32_t _rise; uint32_t _fall; uint8_t _count; uint8_t _channel; static uint8_t ...
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1answer
58 views

Not able to control DC motor speed with l298N & pwm pins

I am using arduino uno to control dc motor speed with L298N. But the problem is that the motor is only going at max speed. PWM pin doesn't work for some reason. I heard many people had some problem ...
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45 views

Ultra Long Range (200-500km) Arduino Communication using a Gibson Girl

I came across this article on Hackaday showing a simple AM transmitter sending a morse code tone 700km! I'm looking into a EPIRB for myself while deep in the bush / outback hunting or camping, just ...
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1answer
64 views

What is the difference between the two sensors? [closed]

I am working on a project which requires the use of sensors and i don't know which one to use so i would like to know the difference between the two.
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0answers
23 views

Unable to read data more than once via Modbus RTU

I'm a newbie to this forum so kindly excuse me for any errors. I'm using an Arduino Uno and Max485 (RS-485 to TTL) to communicate with a Power meter, but I'm able to receive the data from the Power ...
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0answers
76 views

Arduino Uno & ESP32 communication using RS485

I am trying to establish a communication between Arduino Uno ( Master) and ESP32 (Slave) using RS485 protocol (using MAX485 module). I have successfully done this between two Arduino Unos. ...
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2answers
59 views

Serial.available is working only for the first time

I am working on RFID. I am sending data through serial monitor and the Serial.available is not identifying the data after the first time, its working perfectly fine only once after reopening the ...
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2answers
87 views

LED on same Pin as Toggle Switch, not illuminating

I am trying to do something I think should be relatively simple. I would like to read an input from a toggle switch, and have a red 5mm LED indicate the state of the switch. Rather, however, than have ...
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2answers
104 views

Arduino WiFi Rev2 JSON String

I have been trying to use the WifiNINA library to access the JSON output from the following API using the WifiNINA library and the Arduino Wifi Rev2. This is the code that I have been using (it is an ...
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0answers
39 views

Problem using 74HC595 with ULN2803A as LED driver

For a final project I'm making a word clock using three 74HC595 registers and three ULN2803A transistor arrays as led drivers, as well as a DS1307 RTC. The program works great, except for one large ...
0
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1answer
32 views

Why is IF statement executing on itself

x = 5; Serial.println (x); if (x == 0); { //stuff in this IF keeps happening why ? //Iam too stupid ? }
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1answer
41 views

How to calibrate the MQ7 sensor module?

I recently bought a MQ7 sensor module like the one in the attached picture. I have read several tutorials, and they're all different. Some of them says that i need to connect the module directly to 5v ...
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1answer
41 views

Wire with MCP23008 I/O expander with I2C

I'm trying to read from an MCP23008 I/O expander using the Wire library over I2C. The MCP23008 is wired to address 0x04, giving an effective device address of 0x24. Writing to the device GPIO seems to ...
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0answers
41 views

Circuit diagram for running bipolar stepper motor using LDR

I am new to Arduino, some how I have put this code together to run stepper motor using LDR(kind of solar tracker program) I searched on net and tried using servo motor circuit to run stepper motor, ...
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1answer
61 views

Digital map in A* search algorithm in Arduino [closed]

I am building an Automated Guided Vehicle as my graduation project. I'm new to path-finding algorithms and I've only worked with small projects based on Arduino as of now. I've chosen A* search after ...
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1answer
40 views

Can't store RFID data in the next 5 bytes of array

I'm working on RFID project to handle multiple cards. I did most of the things OK. But now I have one problem. Which is the following: The RFID code is 5 bytes, so I need an array of 5 bytes. If ...
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1answer
73 views

Arduino freezes while running code

I am frustrated with my arduino project can you help me? I am using Arduino Uno, electric lock (high/low), 4 distance sonic modules. Basically I have 4 drawers, I am measuring the distance - how much ...
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1answer
110 views

Remove gravity from accelerometer of MPU-6050

I am currently working with MPU-6050. Now I want to minus gravity from my accelerometer's value as we minus the offset. Here is the code: #include <Wire.h> #include <MPU6050.h> //read as ...
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1answer
42 views

I am building an robotic arm by using flex sensor, servo and 2 xbees

Rx Code: #include <Servo.h> Servo myServo; void setup() { Serial.begin(9600); myServo.attach(9); delay(5000); myServo.write(0); } void loop() { while(Serial.available()==0); int d = ...
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2answers
63 views

How to sample incoming 600khz pin and divide it by 4 and generate low frequency signal at output pin of arduino

I am trying to divide a incoming high frequency signal 600kHz by 4 and output wave at arduino MEGA2560 digital pin. The input to arduino comes from incremental Encoder which is connected to motor ...
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0answers
42 views

Can't parse large json file

For a project I've to parse a big json file. Unfortunately it does not work as expected. Here is the json file: { "data1": "...
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0answers
27 views

Arduino Uno 3.3V pin to GND short how to fix

Hi I am new to the Arduino world. I was playing around with my Arduino UNO making LEDs go on and off in a sequence. Then I connected a motor to the N.0 pins but found it doesn't work so I plugged it ...
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0answers
22 views

Serial Communication between ESP-01 and arduino [duplicate]

I want to send sensor data from arduino to esp-01 and it further goes to firebase. And also wanted to send status of water pump from firebase back to the arduino to control motor manually. So what pin ...
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0answers
14 views

5/2 solenoid valve with arduino [duplicate]

I have four bistable solenoid valves that I want to control using Arduino. They use 24V and are pneumatic, in other words they will be controlled through the Arduino and air. I have looked at a lot of ...
0
votes
1answer
48 views

Invoke a method in the main sketch from within a library

I need to use a specific library that issues error messages in the form of String texts. The library uses the Serial.println() function to send the messages to the Arduino IDE's serial monitor. The ...
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1answer
43 views

Limitations of connecting to many Arduinos via Ethernet?

I'm planning a project where I need to control a lot of Arduino Unos from a single PC. I'll need to send commands to the Arduinos and receive responses, as well as have the ability to update each ...
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0answers
21 views

Controlling multiple Screens using IR

I'm a software Engineer, and recently I’ve been working on a new Software Part of this Software is to be able to turn off and on multiple TV screens using timers in the software First idea came to my ...
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0answers
34 views

PWM C Code some logical error

I don't know what's wrong with the code I have activated all the bits I need. I want the code to slowly increase the brightness of the bulb and then reset and then the same thing goes on. Please help ...
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2answers
65 views

Sporadically corrupted data returned from ESP8266

I have an Arduino Uno connected to an ESp8266 via an ESP-01 adapter. The Adapter is powered from the Arduino 5v and Gnd pins and the Tx/Rx to the Adapter use Arduino pins 2/3. I have basic code which ...
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2answers
40 views

May mulitple sensor connect to one arduino uno board since they shared same pin? [closed]

i am a Arduino beginner here. I start knowing about Arduino since my supervisor give me this project. In my project , i need to invent a car safety system to avoid animal hurting that hide under ...
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1answer
38 views

How to Connect TFT LCD display with NodeMCU?

I am doing this project wherein I want to display some image on the LCD screen. I am having a problem with the connecting nodemcu with my TFT LCD screen. I cannot find any references. Does a TFT ...