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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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20 views

nodeMCU - 2 loops at a time - one continuously and second every 10 seconds

i have nodeMCU v3(esp8266) so i need to make 2 checks 1 check is the pin D1 which needs to be done continuously and another check is web link check every 10 seconds, problem is coz when i put delay ...
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0answers
16 views

nodeMCU - when DC is active on pin the do this

i have a nodeMCU v3(esp8266) and what i want is: when i send DC 5v or 3v to a pin=D1 (idk if its possible to send 5v directly to pin) then to activate the D0 for 20Seconds like this: if (D1==Sends ...
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0answers
45 views

Can't POST data with Arduino and ESP8266

I'm having problems with my Arduino UNO and the ESP8266 module. I need to send values from Arduino to my PHP web page in this way: http://www.server.com/km/db.php?id=53 the ESP8266 module is working ...
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1answer
21 views

Arduino Uno - Variables randomly changing

So I have a circuit for a timer (I don't think it is the problem) Sorry for it being a little messy. And I have this code (probably the problem): // LiquidCrystal - Version: Latest #include <...
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0answers
29 views

How to send message to multiple number using arduino and SIM900A mini v3.8.2?

I am using this code to send message using Arduino Uno & SIM900A mini v3.8.2 module. But I need to send same message on multiple numbers. #include <SoftwareSerial.h> SoftwareSerial SIM900A(...
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1answer
40 views

A1-A5 pins not declared in this scope error

When I set my board to 'Generic ESP8266 module' then only A0 pin of arduino is working while all other analog pins are coming out of scope , when I set the board to 'arduino /genuino uno' , then "...
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0answers
11 views

RS256 JWT with Arduino

I am working on a project where I am implementing JSON web tokens to validate devices on a server. I have been unable to find many resources related to RS256 JWT with Arduino or similar devices. ...
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0answers
27 views

Arduino uno and Nano as master and slave [duplicate]

please help me!! I'm using two arduino (uno and Nano) as master and slave. I wants to control 3 servo which are connected on Nano (slave) by uno (master). Uno have 3 push buttons on it to control ...
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0answers
36 views

Problem interfacing both esp8266 and EM18 with Arduino Uno

I have connected esp8266 with Arduino Uno and programmed 8266 with Arduino IDE to send data to firebase over WiFi. Now I also want to interface EM18 RFID Reader with Arduino in order to read the RFID ...
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1answer
40 views

How to upload and store settings/variables from computer on the arduino? [closed]

I'm literally as green of a noob as I can be at this moment. Been watching a ton of tuts as I plan my project, but can't seem to find anything about settings being uploaded from an external source, ...
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1answer
445 views

'Var' does not name a type!

I don't have much experience in C++ programming. I'm getting this error 'z' does not name a type!!! which I have't seen in MATLAB or python... What's wrong??? It is so simple!!! float x=10; float ...
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1answer
14 views

avrdude: stk500_getsync(): not in sync: resp=0xyy … where to find the response values?

Last week I retried some of my Arduinos and one Mega was working without a problem, but two Uno's didn't work anymore. The error I got was something like: avrdude: stk500_getsync(): not in sync: resp=...
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1answer
12 views

HX711 Soft WDT Reset

I am using the following code to check if the value is 0 e.g there is no weights placed and if so, it will ignore this value and do nothing with it. The code runs correctly but keeps outputting the ...
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0answers
34 views

sending array of data using spi

am using two arduino uno to start communicating using spi by sending an array of data but actually I having a trouble because the master is only showing me the first byte of the slave's array however ...
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1answer
42 views

Class help - Same Object types seem to mix values with each other

I'm having issues with two objects of the same class type. I have a LED class, which has functions to fade in and out, a LED. In my code, I create two objects of this class, and on the board, I fade ...
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0answers
13 views

Arduino project using SIM808 and send SMS with location

#include "SIM900.h" #include <SoftwareSerial.h> #include "gps.h" //To change pins for Software Serial, use the two lines in GSM.cpp. //GSM Shield for Arduino //www.open-electronics.org //this ...
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1answer
54 views

Esp8266 not responding to GET request from Android app created using MIT App Inventor

I hope I am posting this question in the right section. I am making a Smart Home Project for my college semester finals. I am using an Atmega328p microcontroller along with an ESP8266 (Esp 01). The ...
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0answers
25 views

HX711 Wemos D1 Weird Characters In Serial Monitor

I am using the HX711 with a load cell attached on my Wemos D1. I have the connections correctly as if I use the same setup on my Arduino Uno board and the same code it runs fine and prints to the ...
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1answer
25 views

Byte text file to array [closed]

I'm trying to display a bitmap on gLCD 128x64, I stored the bitmap into txt file 1.txt in a SD card this is a part of bit map as following: 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,...
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1answer
47 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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1answer
17 views

ArduinoJson v.6 equivalent of invalid() [closed]

What is the ArduinoJson 6 equivalent of this statement? root == JsonObject::invalid() I'm using as a condition of if parameters.
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0answers
24 views

Sending to Arduino UNO multiple values from Python code

I'm starting to learn how to work with Arduino, particularly communication between a Python code running on a PC and an Arduino Uno. So I decided to start with what I thought to be a easy task. ...
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1answer
43 views

Is SPI a good way to connect two rfid modules on separate arduino boards?

RFID access control I have two separate rfid projects on separate arduino, the first project requires 2 minutes of contact between the tag and the reader after which it turns the LED on. the second ...
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1answer
46 views

Sending mouseX and mouseY from Processing to Arduino

I'm new to serial communication and trying to send mouseX and mouseY from Processing to Arduino. Serial monitor doesn't show anything. Processing code: import processing.serial.*; Serial port; void ...
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2answers
55 views

How to get average of 16bit ADC readings?

I have an Adafruit ADS1115 analog-to-digital converter, configured in single ended mode. I want to average over 3 sensor readings to increase the reading stability. //initialize variables int16_t ...
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1answer
37 views

Why can't I switch off the LED immediately using this sketch?

I hope the LED can fade out a period of time. Also, I hope I can switch off the LED immediately when it is fading, but I only can fade out. const int buttonPin = 2; const int ledPin = 9; const int ...
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1answer
63 views

Is there a way to have the LED switch on after 10 readings or say a minute?

I am using Arduino for a RFID project where the LED must switch on after either 12 readings of the tag or 2 minute, the tag reading happen every 10 seconds. I can't seem to figure out a way to have ...
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0answers
23 views

Voice Recognition and then read CSV

BLUF: Is it possible to use a shield to recognize a voice command like a name, then look for that name and info in a CSV file and then store certain info as variables to then actuate something? ...
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5answers
84 views

Fan regulator control from Arduino

I'm trying to control my ~230 V fan from the Arduino. Can anyone say the best possible ways to design a fan regulator that can be controlled by the Arduino using a low cost design.
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0answers
72 views

Trying to use an Arduino Uno together with an ISM330DLC communicating through SPI

I am trying to get a MEMS-module (ISM330DLC) to work together with an Arduino Uno but I can't get it to work. I am using the ism330dlc drivers. ISM330dlc Drivers: https://github.com/...
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1answer
197 views

Triggering an ultrasonic sensor

I made a smart blind stick for my class project. It uses an ultrasonic sensor to detect obstacles and I was asked this question in VIVA... Why is it necessary for giving a digital high for 10 &...
3
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1answer
54 views

cannot convert 'bool' to 'PinStatus' for argument '2' to 'void digitalWrite(pin_size_t, PinStatus) on Arduino Uno Rev 2 Wifi not working

I am a newbie to micro controllers and struggling to figure out how to fix this issue. When using an older Arduino micro controller it works fine, but when I use a new board (Arduino Uno Rev 2 Wifi) ...
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0answers
26 views

Arduino Light Puzzle Help [duplicate]

This is my first time doing this type of thing and I have no background in coding. It will compile however the code won't upload and I've been working on this for days. Any help you can provide ...
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0answers
24 views

Control motor DC with buttons

i'm new user with Arduino, i want to know if there is a tutorial to control the rotation of a motor like : with 4 buttons, the first to rotate +pi/2 the second to rotate -pi/2 the third to rotate +-pi ...
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1answer
40 views

Modifying a code

I use this code to turn on/off a small 5v dc motor. How can I modify it so that the arduino writes the potentiometer value to the motor when it is in ON state ? int speed = analogRead(pot) / 4; ...
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0answers
25 views

BLUETOOTH MODULES Arduino

I am new to the world of electronics so please forgive me if I ask stupid questions. I would like to ask if there is a difference between Bluetooth Modules that state: "for Arduino" as well as those ...
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2answers
55 views

Problem of repetition

I have encountered a problem concerning the repetition of the program that means it executes once (since the sensor passes to 1 it calculates 5 seconds (the sensor is still at 1) after the lamp is lit)...
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1answer
34 views

Conditions with GSM module SIM900 doesn't execute

I'm executing this code to control a LED with GSM SIM900 message but there are two problems. First, it receives messages sometimes and some times doesn't. The second is that it doesn't execute the if ...
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1answer
39 views

Is it possible to send a float Array over I2c

I have tried it several times myself but i never could send or receive it properly. I am asking myself if it is possible and if so could someone explain how? Cheers.
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0answers
55 views

Send data string from Arduino UNO to ESP8266-01

Is there anyway to send a string from an Arduino UNO to a ESP8266-01 (one with only 8 pins RX, TX, CH-PD, vcc, ground, reset, GPIO0, GPIO2) without using without using AT commands. I've looked ...
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2answers
47 views

Problem with LCD

I'm working on this piano project. When I push a button one of the led light is suppose to turn on and a tone comes out of the piezo. The LCD screen is suppose to print out a sentence but I can't get ...
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1answer
20 views

WiFi Connection With a Enterprise WLAN

I have an ESP32 and want to connect it to the WLAN at my office. Based on my current knowledge of the Arduino, we use the WiFiClass to connect to a WLAN and then use a WiFiClient to use the WiFi for ...
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1answer
23 views

Analog reading with noise - Arduino Uno VS ESP12e

I was testing analog output from a microphone (Max9814) with an Arduino Uno, which came with nice results. The output provided by the microphone is converted into sound and is loud and clear. Setup: (...
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1answer
75 views

Send Multiple Value from Arduino uno to nodeMCU using serial [closed]

I want to send 7 sensor data from Arduino uno to nodeMCU. But using serial I can send only one. How to send all 7 at the same time with time sync between the both devices.
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0answers
34 views

Arduino Uno Controlled Heater

I am a novice in Arduino. I am working on a temperature controller for a hot plate. I have a PT100 as sensor which is being driven by a 1mA constant current source. As the resulting output voltage is ...
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1answer
48 views

My Code turns on my LED even when my switch is not pressed

I am trying to create a circuit that will turn my motor when I clap. When the first limit switch is low, and there is only one clap, a solenoid pin is supposed to be engaged (currently an LED), but ...
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0answers
16 views

SoftwareSerial HC-05, ASCII “T” to turn on LED, doesn't work [duplicate]

Arduino Uno / HC-05 / ArduinoIDE App on my phone: "Bluetooth Terminal HC-05" I want the program to turn on the native 13th pin LED ON, if incoming text is "T" and turn it OFF if incoming text is "F". ...
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0answers
57 views

MQ7 Flying Fish output format

I am new to Arduino project. I used MQ7 flying fish sensor to sense the CO. Ok now I connected everything as mentioned in various tutorials, such as Arduino CO Monitor Using MQ-7 Sensor. Also wrote ...
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2answers
87 views

Why does current flow along a wire instead of a resistor right next to it? [closed]

I am having trouble understanding exactly what is going on in a circuit where when a button is pressed an LED goes on. Also, I have the Arduino UNO. The schematic can be seen at: 2:36 of this video: ...
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0answers
28 views

Reading incoming/outgoing bytes from SIM card / ATR

I am trying to read data from a two-way I/O uart pin of a sim card on Arduino. It is attached to the GPRS Arduino shield (with SIM900 modem). I believe I have a baud rate issue. I am supposed to ...