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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Arduino Nano R3 & Deek-Robot datalogging shield

Whilst I am much more at home programming PIC ISR's in assembler, I am building a data logger using a DS1307 to interrupt every second to write data to a USB SD card. There does not appear to be a ...
0 votes
0 answers
62 views

DS3231 with Arduino Nano for Timing precision

I am in need to synchronize two separate circuit boards working with Arduino nano. The need is to activate one relay using Arduino-1 after 45 min and another relay using Arduino-2 after 45.36 seconds. ...
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1 answer
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Issue wth using ENUMs in oop arduino code [closed]

this is my first time prototyping something in arduino. What im basically trying to do is an airsoft target practice game using a piezo sensor and leds to indicate whether the piezo has been hit. I've ...
2 votes
1 answer
240 views

Direct port manipulation takes 300 nanoseconds to execute for some reason

I have this code #include <Arduino.h> void setup() { DDRD = B00001000; } void delayNanoSeconds(int time){ int ans = (float)time / 62.5; for(int i = 0; i < ans; i++){ ...
-2 votes
2 answers
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How to get more volt ports on Arduino [closed]

I am using an Arduino Uno which has a 3.5 volt port and a 5 volt port. I am hovewhere using an ultrasonic sensor which requires 5 volts but is working with 3.5 and I am using a photoresistor which ...
-1 votes
0 answers
86 views

Troubleshooting PWM library and SD card data reading in Industrial AC Servo Motor Control Project

First of all, I apologize for my poor English. I am currently experiencing a problem with a code I wrote for a project I am working on. In my project, I need high PWM frequencies, so I am using the ...
-2 votes
0 answers
18 views

I want to capture the blood pressure in the hand vessel. With the AS7265X [closed]

I try to capture the blood pressure of hand with the NIR sensor As7265x. However, I am not electronic engineering and I didnt have background. I am seeking help
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0 answers
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I want to know how to connect AM2301A to lcd keypad shield and adruino uno and code and 1 relay [closed]

I have an AM2301A with 16x2 lcd keypad shield and adruino uno. I am finding it difficult connecting the temperature and humidity sensor to lcd keypad shield and ardriuno uno board. I want to be able ...
1 vote
0 answers
57 views

Unable to use RF M4 Receiver with servo motor

I am trying to control a servo motor with the following code: #include <Servo.h> Servo servo; int const inputPin = 3; void setup() { Serial.begin(9600); servo.attach(9); pinMode(...
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how can i go to another url page in arduino

hello i have 2 room and esp8266 then I have set one of them at the address 192.168.1.19 and the other at 192.168.1.20. I want to put the local address of the other in the form of a button on the page ...
-1 votes
0 answers
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2d array(array of arrays) [duplicate]

While making a library for Arduino, how do I make the library to refer to a 2d arrays a user sets?? Like if a user sets arrays like this: int arrays[4][3]={ {1,2,3}, {4,5,6}, {7,8,9}, {10,11,12} }; ...
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SIM808L 2.0 won't connect to Arduino

I have an Arduino Uno and a Sim808L 2.0 (https://arduin.ro/products/modul-sim800l-20-5v-wireless-gsm-gprs-quad-band-cu-antena). I try to connect the module, but it won't connect. After some time, the ...
0 votes
0 answers
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need help to troublshoot diy arduino board

i have designed arduino compatible diy board with Atmega328p-Pu. i have burned the bootloader for first time and the upload blink example to board and didn't get any error. when i upload another ...
0 votes
0 answers
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How to rescale tension in input A0 [closed]

I am trying to read a voltage which at some point is higher than 5V, so the readout saturates at ~1000 and cannot read higher values. How could I rescale the input so that the arduino readout does not ...
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0 answers
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How To Sync 2 LEDS with a tune played with Piezo Buzzer [duplicate]

#include <Tone.h> #define NOTE_B0 31 #define NOTE_C1 33 #define NOTE_CS1 35 #define NOTE_D1 37 #define NOTE_DS1 39 #define NOTE_E1 41 #define NOTE_F1 44 #define NOTE_FS1 46 #define NOTE_G1 ...
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1 vote
1 answer
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Wire.write invalid conversion from ‘char*’ to ‘const uint8_t*

I have written this code: char message[4]; memcpy(message, &delta, 4); Wire.write(message, 4); When I try to compile I get this warning: warning: invalid conversion from ‘char*’ to ‘const ...
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0 answers
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How to calculate the angle of directions (North-South-East-West) using Nicla Sense ME?

I am working with the Bosch Nicla Sense ME board(BMM150). I used the following code to find the Magnetic field intensity and angle of the direction. With the x,y, and z reading, I don't know how to ...
-1 votes
0 answers
25 views

Arduino Uno WiFi Rev2 can't connect to the wifi

please give me some slack this is my first question. I'm currently using An Arduino Uno WiFi Rev2 and I'm trying to connect to the internet, both with my own code and the built in examples on the ...
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-2 votes
0 answers
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A circuit with earbuds [closed]

Is it possible to make a system where earbuds will be connected to Arduino and the Arduino will be connected to your phone, so it doesn't matter if your mobile is not with me? (Like if I want to just ...
0 votes
0 answers
25 views

Color Sensor accuracy

I have this project using a color sensor (TCS230) and I hooked it up to my Aduino. My goal is to recognize different shades of color accurately. What I mean is there are different shades of color. For ...
-1 votes
0 answers
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Serial.readString() will not grab all parts of the JSON that I send over [duplicate]

I have an Arduino UNO and an ESP32 that need to communicate to each other using SoftwareSerial. The problem I am coming across is that when I call readString and print it out using Serial, it will not ...
0 votes
1 answer
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Arduino nano timing precision

How precisely can an Arduino nano be timed? The project I am working on needs two Arduino nano to work synchronously. Arduino one have to activate a relay after 2700 sec and Arduino two have to ...
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-1 votes
1 answer
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Why is my simulation giving wrong values?

I'm building a keypad for my project , due to much things needed for the project I decided To make a multiplexer keypad. I made it using my offline icircuit simulation app on my android and it's ...
0 votes
2 answers
47 views

SoftwareSerial will not read all of the printed string when calling readString()

I have an Arduino UNO and an ESP32 that need to communicate to each other using SoftwareSerial. The problem I am coming across is that when I call readString and print it out using Serial, it will not ...
0 votes
1 answer
34 views

I have this code, I want static display on P10 dot matrix display (DMD). But because of loop, display again and again flickering

// Insert file Library #include <SPI.h> #include <DMD2.h> #include <fonts/Arial_Black_16.h> int Sensorpin = 4; // IR sensor int sensorstate = 0; // IR sensor initial state ...
-1 votes
1 answer
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Non-Contact Water Level Sensor output voltage not equal to VCC-in [closed]

I have a non-contact water level sensor. https://botshop.co.za/products/non-contact-liquid-level-sensor-5-12v-npn?currency=ZAR&utm_medium=cpc&utm_source=google&utm_campaign=Google%...
0 votes
1 answer
60 views

Making library for arduino

I'm learning library making on arduino , I want to make a library that works with arrays a user sets, e.g: User sets array of int, when a certain function is been called the library will check if ...
-1 votes
0 answers
91 views

How to plot the data through serial plotter for the attached code?~Why it is coming like attached clips?

WHY RAW VALUE & SCALE VALUE DIFFERENT FOR Things Speak & Serial monitor at a time? For UNO: int analogPin = A3; int Rawval ; // variable to store the value read int Scaleval ; int RELAY_pin ...
0 votes
0 answers
28 views

How to use arduino sensor shield v 5.0 and 2 L298N drivers at the same time for wall following car with 4 mecanum wheels?

I'm still a newbie in arduino but I'd like to try to make wall following car by using: Arduino Uno 4 DC motors 3 HC-SR04 ultrasonic sensors Sensor shield V5.0 2 Li-ion batteries in series Should I ...
-2 votes
1 answer
80 views

Arduino code giving error while compiling [closed]

I am a beginner, and I'm trying to make code to control a servo using two ultrasonic sensors. I've tried to make the code, but when I tried to compile it using my simulation app, it gives this error: ...
2 votes
0 answers
42 views

Curious Collision between OneWire and RadioHead

The code below runs on an Arduino Pro Mini (8MHz 328p) sending temperature readings using an inexpensive ASK transmitter. I use OneWire to read the DS18B20s, and RadioHead to manage the radio. The ...
0 votes
0 answers
27 views

SPI - CS Intermittently Goes High on Arduino UNO

This question is similar to SPI - Apparently Random pulses on CS/SS line in that I have a single SPI peripheral (a Microchip 23LC512 Serial SRAM) that an Arduino UNO is communicating to. Everything is ...
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0 votes
0 answers
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I need help with serial communication between Arduino Uno and NodeMCU

I want to transfer analog readings i.e. variable values from a NodeMCU to an Arduino Uno so that on the Arduino side I can check those values using an if condition and make a buzzer sound. Please help ...
-1 votes
1 answer
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How to read analog sensor data with different timers in arduino

I have three analog sensors like voltage, temperature and pressure. I need to measure the voltage and temperature every 10 ms and I need to measure the pressure alone every 30 ms by using the timers ...
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0 votes
0 answers
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Heating a coil with Arduino and Relay

I was making a circuit to heat up a coil for 3 sec, the circuit I have tried is attached here within. The relay used is activated with Arduino using the pin A5. The power to Arduino and the coil is ...
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3 votes
1 answer
89 views

Detecting an approximate angle/location of a light source using phototransistors

Note: [I am approximately two weeks into learning Arduino and hence have little experience with utilizing Phototransistors.] My plan revolves around placing four identical Phototransisors which are ...
-1 votes
1 answer
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Arduino Facial Recognition Locking System

I'm an extreme beginner in Arduino, so please forgive me if I'm asking basic questions. Essentially what I'm trying to create is a facial recognition locking system. I have experience with Python and ...
1 vote
1 answer
46 views

DHT11 temperature and humidity sensor Code

I’ve got a question about this code I’ve attached please- would it be correct to read it like this: After defining the variable temperature and humidity and assigning measurement_timestamp to millis(),...
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-1 votes
1 answer
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no matching function for call 'HttpClient::HttpClient()'

Board Arduino Uno (include "HX711.h" ,include "HttpClient.h> in void loop(){ HttpClient http; } compile error same header please help for fix problem thank you My code #include &...
0 votes
2 answers
68 views

How to tri-state output circuit

I need a circuit where an Arduino MCU can set an output to 3 different states. HIGH (12V) LOW (GND) N/A (completely disconnected) Using transistors seems to be the correct way but I am too much of a ...
2 votes
1 answer
41 views

Ramping servo motor taking longer than calculated

I'm learning how to code a "BOE Shield bot" with a partner at my university (first year). To clarify for those that do not know: a BOE Shield bot is a small robot equipped with 2 servo ...
0 votes
0 answers
35 views

Telnet connects to the Arduino (with Ethernet Shield) only once. But not the second time

I use Arduino Uno + Ethernet Shield, to wake up PC in local network. The Sketch I have got from here https://github.com/teravice/Arduino-WOL/blob/master/arduino_wol.ino github.com/teravice/Arduino-WOL/...
0 votes
0 answers
28 views

Arduino-CLI not creating sketches in the correct directory despite correct environment variables

Stuff you need to know to answer accordingly: I am using an old Raspberry Pi 3 Model B v1.2 as a Linux machine to learn Linux and experiment with apps. I have used a full command line interface of ...
-1 votes
1 answer
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4x3 keypad not providing any output and the output it does provide is incorrect

I am trying to figure out how to use a 4x3 keypad and just want to receive the key numbers I select on the serial monitor. The problem I am getting is that some of the keys I type don't give me any ...
2 votes
2 answers
25 views

Can a three wire Electrical conductivity sensor (Sensorex CS 150) be used directly with arduino?

I am having an electrical conductivity sensor (Sensorex CS150 with three tinned wires Red, Black and white https://sensorex.com/product/sensorex-cs150-12-mm-graphite-contacting-conductivity-sensor/ ). ...
-1 votes
1 answer
43 views

How do I stop my servo from repeating the loop and perform the rest of the functions?

The project has a makeshift meter (via a half circle cutout and a servo motor operated lever). On program start (button 2), the lever will move to the left hand side at the 9 o'clock position. Once in ...
1 vote
1 answer
89 views

i need help on how to use busy pin in df player to arduino

i need help on how to use busy pin in df player to arduino.... while playing one sound or df player is busy, i don't want to trigger df player by ultrasound sensors to play another song. here is my ...
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1 vote
0 answers
38 views

READ 433mhz DEVICES

I have an issue with 433mhz reading. I have two cheap transmitter and receiver boards, the most known ones : I followed several tutorials, and I'm using the rc switch library. I'm trying to read the ...
1 vote
1 answer
160 views

Run encoder code simultaneously with other code in Arduino

volatile unsigned int temp, counter = 0; int county=0; void setup() { Serial.begin(9600); pinMode(2, INPUT_PULLUP); pinMode(3, INPUT_PULLUP); attachInterrupt(0, ai0, RISING); ...
1 vote
1 answer
88 views

Issue communicating with ESP32 (WT32-S1) with my USB FTDI (hw-417-v1.2)

Basically im trying to communicate bewtween my ESP32 (WT32-S1) and my USB FTDI (hw-417-v1.2) when I run it in the Arduino IDE I get the error "Failed to connect to ESP32: Serial data stream ...

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