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1500 questions
4
votes
2 answers
Photoresistor is not working, is there something wrong in the code?
I am trying to make the photoresistor work in a simple project.
The project is as follows:
The LED light should light up brighter and brighter as the photoresistor reads less light in the room.
The problem:
The reading is fixed on 1023. Therefore…
mickkk
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4
votes
2 answers
Which kind of diodes I should use in buttons/keys matrix input? (Making gaming keyboard)
When making matrix input of NxM columns/rows with push buttons, there should be a diode next to each button to prevent "ghosting" and able read many keys pressed together correctly. There is a lot of pictures everywhere.
My problem is, which diodes…
gilhad
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4
votes
2 answers
Multiple libraries were found for "WiFiClient.h" using nodemcu
I am trying to send HTTP requests from nodemcu so I started by uploading the esp8266 library but when I run the following code
#include
#include
void setup() {
Serial.begin(115200); …
Ela Hidri
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4
votes
4 answers
class enum was not declared in this scope
I am programming an Arduino. In the same .ino file as setup() and loop() I have defined the following:
void setup()
{
// setup code
}
enum class CYCLE { TypeA, TypeB };
String cycleToString (CYCLE cycle) {
if (cycle == CYCLE::TypeA) {
…
AJP
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4
votes
1 answer
Can I use an AC signal to make an LED light up with arduino?
I want to use a 220VAC load as a signal and act as a switch to my arduino so Labview could interpret it as an LED ON state. I used a 4n33 octocoupler but it seems that the LED Simulation on labview keeps fluctuating. I think it's because of the…
James Nunieza
- 49
- 1
4
votes
1 answer
Can I program a factory fresh Atmega328P through UART pins without burning a bootloader?
Can I program a factory fresh ATMega328P using the UART pins without burning a bootloader? These pins are TX, RX, VCC, GND, and DTR pins in the schematic below. They are not the ISP/SPI pins 10-13.
Arduino Pro Mini schematic
For example, if you…
Bort
- 151
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4
votes
1 answer
Have I fried my A2 port?
I'm playing around with a SparkFun Redboard (essentially, an Arduino UNO).
I have a simple 5V sensor that I'd been trying to get to work with A2 and analogRead(). Nothing seemed to work. It's supposed to be cycling from 0 to 5V, which should give me…
Jeff Dege
- 161
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4
votes
3 answers
Is there any limitation with Arduino Nano serial communication distance?
I am trying to build Project which communicate multiple Arduino Nanos. I wanted to understand if Arudino Nano is capable of doing that, while doing research I came across post where it says communication with nano can be done up to 2-3 meter, where…
Akshay
- 193
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4
votes
2 answers
What sensor do I use to measure the intensity of direct sunlight?
I'm trying to measure how bright the day is on a particular day to see how it affects plant growth. The brightest sun can be 120,000 lux. It possible to measure such a large brightness? What sensor do I use?
The best options I've found is the…
Amin Shah Gilani
- 151
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4
votes
3 answers
Using an external header file
I have a project that is part of a larger repository, and shares header files with non-Arduino C programs.
I know that it's possible to use these headers by copying them to the libraries folder, or the sketch folder, but I would rather use them with…
Photon
- 163
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4
votes
3 answers
Esp8266 Vin pin
I've read that Vin pin is directly connected to usb cable in esp8266 (which is 5V). I wonder if I can power a relay 5V and a servo motor Sg90 with this pin? And is there any danger of doing that ?
Radja
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4
votes
1 answer
What does "Update of OCR1x at" mean in the WGM table of ATMEGA328?
I just finished a reading a couple of online guides on how to use timer registers with pulse width modulation, so I'm still new to its concept. When I looked in the ATMEGA328 specification sheet, I see this table:
The column that I'm not…
learningtech
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4
votes
2 answers
Why is AREF connected to a capacitor in the Arduino Pro Mini Schematic?
I'm currently looking at the Arduino Pro Mini schematic and have noticed that the pin AREF (analogue reference) is connected to a 0.1uF capacitor as shown below:
I have done some research and read this great explanation into AREF and now understand…
Lachlan Etherton
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4
votes
2 answers
Need little bit of help on testing I2C sketch
I have this code I got from YouTube for communicating between two Arduinos. By typing 'R' manually into the serial monitor of the 'master' Arduino, the 'slave' will print "Success". I'm trying all this for the basis of a project I'm starting.
After…
Josh
- 51
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4
votes
2 answers
Good quality sound using a microcontroller
I am a hobbyist. Doing some experiments with sound quality. I'll pin point my problem and requirements.
Problem statement :I want to play audio files ( recorded in human voice, not music files, just some plain human speech files)
I have tried : a…
muphy
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