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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Why doesn't LCD 16x2 work with fingerprint sensor code?

When I separate fingerprint code and LCD code it works fine. sensor read 6 templates which I already stored 6 fingers ID. When I combine the code it read 0 templates. #include <Adafruit_Fingerprint....
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156 views

Sim800L-v2.0-network-problem

I am having trouble to get Sim800L-v2.0 to work. I believe that I am supplying the necessary amount of current (5.0V, 2.1A máx power source, using solid copper wires - circuit photo). The Net LED ...
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478 views

Reading JSON from Arduino over serial in python and writing to a JSON file on computer

I'm fairly new to Arduino so I used a sample code before integrating this into my main code. I'm printing my value in a JSON format over serial. My Arduino outputs this and the python receives this ...
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2answers
100 views

Running an Arduino without the computer

I am having trouble getting my Arduino uno to run my code when I disconnect it from my computer. I have a 9V battery to power it and it is turning on, however, it is not doing anything at all. What ...
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74 views

How can you turn off the LEDs on a SparkFun AS7265x Spectral Triad (Spectroscopy Sensor)?

I'm a newbie to program an Arduino but I need to turn off a LED from a external Spectroscopy Sensor. This is the Sensor: There are three LEDs on this sensor and they're turned on automatically when ...
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28 views

Brushless motor vibration/jitter/noise - arduino uno

I am currently using these motors and driving them off these drivers and an arduino uno, and alternatively trying to make them turn using the setup in step 6 (both with l298n and without) in this ...
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82 views

Please help with my tinkercad code. Debouncing stopwatch with lcd

#include <LiquidCrystal.h> LiquidCrystal lcd(12, 11, 5, 4, 3, 2); int ssPin = 8; int resetPin = 9; bool cntrRunning = false; int sec = 0; int min = 0; double currentMillis; void setup() { ...
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32 views

loop once per startup for stepper motor

First of all sorry that i dont know much about programming, most of my codes are just copy paste. And of course, i know this question has been asked before, but while using this code: #include <...
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1answer
99 views

RS-485 Serial communication problem with arduino

I use 485 modules to transmit data serially from one arduino uno to another uno. If I connect the 2 arduino boards directly without using the rs485 module, the data is sent and received without a ...
2
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1answer
129 views

Set control register to low in ds3231 rtc

I have been using ds3231 rtc module for keep tracking and make alarm along with backup battery. when I used it for first time it worked fine. but now it doesn't keep track my time when the power lose ...
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35 views

Wire Halloween Wolf to howl with Arduino motion detector

I bought one of those Home Depot halloween wolves that howl. You can control it with a push-button to be on, or off. It has its own power source via 3 AA batteries that power the howl sound, red eyes ...
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46 views

FIFO overflow with DMP on MPU6050 and OLED

I am using the DMP example code to get yaw pitch roll values, mainly I am interested in pitch value for building a self balancing robot. I am trying to display the pitch values on an OLED screen but I ...
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57 views

Arduino Voltage Reading Problem

I was trying made a gear indicator for my bike, with manually sensing the gear shift. But failed, cause my bike has no separate "neutral" wire, instead there is gear sensor in-built...!! ...
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1answer
34 views

How can i make my MLX90614ESF scan temperature after the MFRC522 scans the RFID tag?

//THIS IS THE RFID CODE #include <SPI.h> #include <MFRC522.h> #define RST_PIN 9 // Configurable, see typical pin layout above #define SS_PIN 10 // ...
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1answer
99 views

Interrupts Within Critical Statements

I've redone a previous Arduino sketch I posted in which I was having trouble capturing encoder counts within critical statements, having no luck properly attaching and detaching interrupts. I've ...
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254 views

1.7 MHz generator for a water atomizer

I'm creating a controller for a small greenhouse, I have a DHT22 for measuring and two relay module that controls heating and cooling systems, and I will use a piezo to produce humidity when it goes ...
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84 views

Problems with Arduino Uno Usb 2.0 shield when using a keyboard

I have an Arduino Uno and a usb 2.0 shield in which I connected a keyboard to. I have all the necessary libraries installed but what I am trying to figure out is how to light an led when I press a ...
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70 views

Arduino EPROM dumper with utility program in C

I am writing EPROM dumper with Arduino UNO and utility program in C and I am using Ubuntu 20.04. The Arduino sketch works fine, but I am having few problems with the utility program. The first problem ...
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375 views

Data transmission rate of accelerometer mpu6050 to arduino uno vs Sampling rate of mpu6050

mpu6050 has sampling frequency of 1kHz (mentioned in datasheet). But when i interface it with arduino uno via I2C communication (400Khz bus speed), i only get 50 raw data (each of x,y,z). There is no ...
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2answers
712 views

sleep mode and watchdog at the same time

suppose a project with Arduino that we should save battery power, so we use sleep mode and also avoiding the Arduino of hanging and use watchdog timer. But the problem is here that when the Arduino ...
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159 views

qMenuSystem using DigoleSerial library doesn’t work on my I2C Monochrome OLED

Just like the title says I’m trying to make qMenuSystem to work with my oled display. Here is what I know so far about my display : - It's a Monochrome OLED 128x64 (Blue) Display - It's connecting ...
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54 views

Arduino Uno - Stepper motor not working with button

I am completely new to Arduino, and all sorts of hardware and software. I have a stepper motor, which I want to rotate by a number of rotations when I press a button, and then go backwards by a number ...
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0answers
35 views

If an Arduino goes to sleep, does the attached ESP also sleep?

I am using Arduino Uno + an attached ESP-01 (ESP8266). I want to save battery, so I made my Arduino get sleep & interrupt by a watchdog timer. But if the Arduino goes to sleep, does the attached ...
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798 views

read with Arduino SSI encoder signal

I'm stuck in my project, I try to read an absolute encoders angular position with my Arduino. I used and cabled a differential line receiver and driver between Arduino and the encoder, like explained ...
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278 views

Compare barcode scanner string with existed string

I have a project which is reading barcode scanner result then compare with an existed string. I have used the library USB host shield in order to read data from barcode scanner then I would like to ...
2
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1answer
285 views

Need help with wire connections and code

I am currently working on a keypad door lock mechanism (Similar to this project, Keypad door lock). The issues with the code I have is that the keypad attached to my board does not allow me to type ...
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0answers
201 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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0answers
143 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 ...
2
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0answers
568 views

Measuring Amplitude/Frequency of sound

I need to read an analog signal at about 500-1000Hz for at least 5 seconds. I've a battery powered microphone wired into an analog and ground pin on my arduino and am trying to measure the frequency ...
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841 views

Arduino + USB Host Shield + ESP8266

I am using an Arduino Uno and a USB Host shield for Barcode Scanner. The whole scenario is that when I scan the barcode through USB Barcode Scanner, it scans and gives a code. Now the question is how ...
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26 views

Selection of External CT for my application

Here I have attached my ckt for my application. My application is Motor protection Relay. Based on Current sense of 3 CT tripping of relay will occur. Tripping might due to under/over/SC/Locked rotor ...
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479 views

Ideal voltage level for attachInterrupt()

Well I am working on old textile machines, it is taking motor RPM with ISR. I want to read this RPM and publish on web. but the output voltage of this old system is 0 and 22 Volt. (0 Volt when the ...
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0answers
448 views

Seeed CAN Shield - Not receiving extended CAN-Message

I want to receive an extended CAN-Message. I send a extended CAN-Message, but nothing happens. Maybe somebody have an idea what the problem is.. It works with a standard CAN-Message. Thanks in ...
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668 views

Arduino Modbus slave error

I am trying to use Arduino as Modbus- RTU slave and Raspberry Pi as a Modbus master I have interfaced Max485 (RS485 to TTL converter) with Arduino and Rs485 to USB converter in Raspberry Pi, Initially,...
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0answers
88 views

Arduino Swissflow Meter

We've hooked up a Swissflow sf800 flow meter to our Arudino Uno. The system works, our interrupt callback is triggered and as water flows through the metre, it counts up. The issue is, that the pulse ...
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0answers
98 views

TLC5917 SPI Speeds

I am attempting to use 3 x TLC5917 chips to drive a row of LEDs in PWM. The LEDs share a common anode being powered through a transistor, with each LEDs cathode going to pins on the TLC5917 Chips. ...
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90 views

Problem with incrementing values of an RGB LED

I'm trying to use a remote control to control the red/green/blue values of an RGB LED using an Arduino Uno. Here's what I've got so far: #include <IRremote.h> #define IRPin 7 #define bluePin 9 #...
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38 views

Arduino Uno with data logging shield has a problem switching power sources

I have the basic Adafruit "Light & Temperature data logger Tutorial kit" made, and it works well when connected to a PC, but when I unplug the PC USB connection and hook it up to another power ...
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2k views

Reading +IPD response from serial.read() using Arduino UNO and ESP8266

I have a python server running on my PC and I am using an Arduino Uno (wifi enabled by a ESP8266 chip) as the client. I can make the the server and client communicate using AT commands as shown below: ...
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56 views

Can only upload certain programs to standalone Arduino

I can't upload a program that uses digitalRead, analogRead, and Serial.print on my standalone Arduino, because I get this error: avrdude: stk500_recv(): programmer is not responding avrdude: ...
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0answers
91 views

SD card doesn't work properly

I have this SD-card module. I have formatted the SD with this tool. My problem is that the Arduino Uno can't initialize the SD. I tried with this script: // include the SD library: #include <SPI.h&...
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1k views

Using the TimedAction library

I need to make use of the TimedAction library for a project. The Arduino website gave an example of how to use this library which you can see here: #include <TimedAction.h> //this initializes ...
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0answers
2k views

NFC PN532 SPI - Error: Timeout when waiting for ACK

I've been struggling to get the PN532 module working over SPI with an Arduino Uno. I have the wires connected as follows: SCK -> 13 MISO -> 12 MOSI -> 11 SS -> 10 VCC -> 5V ...
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0answers
2k views

Send Bluetooth Data to Android App (HC 05)

I'm struggling to send data strictly from my arduino UNO to an android app using bluetooth module HC 05. I am able to send/receive using 1) the serial monitor in arduino IDE and 2) Bluetooth Chat ...
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0answers
116 views

What might be the errors of my codes?

I tried to imitate lagsilva's clock projects using Arduino Uno and made the circuitry, then I've tried to upload the main source code of the author but noticed that it didn't work, so I've edited the ...
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0answers
1k views

NRF24l01+ works only when touching its antenna

I have two simple NRF24l01+ (with range of 200m) and two NRF24l01+ with range of 1km.and two socket adapter. or what I have and I have two good library with names RF24 and RF24-master . problem ...
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0answers
553 views

Soil moisture sensor problem

I'm having a problem trying to run a bunch of code, using an "if" state which uses a variable which should get a value from a soil moisture sensor. I'm using the sensor digitally, so it should just ...
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0answers
942 views

Serial Port Issues Elegoo Mac OX High Sierra

Edit: Unfortunately the question that has been linked to my question does not answer my question. I have followed its instructions but it is a slightly different issue. Any help on my question would ...
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0answers
233 views

Stepper motor just oscillates with arduino and L293D

I am trying to control my stepper motor using arduino duemilanove, with L293D as H-bridge. I use a NEMA 17, stepper motor 42BYGH-036B I have used both the default example program from arduino IDE, and ...
2
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0answers
210 views

Sparkfun Spectrum Analyzer: Problems with frequency bands

I bought around 2 years ago the Spectrum Analyzer Shield from Sparkfun, but I never had the time to do something with it. Recently I found the time to start a project to build a graphical equalizer. ...

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