Questions tagged [electronics]
Use this tag to ask about electronics-related issues with your Arduino. For example: driver transistors, Ohm's Law, current-limiting resistors.
243 questions
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Why connect a diode between the reset pin of Arduino and 555 timer?
I am trying to create a watchdog timer using 555 IC and I am following this.
I do not understand why a 1N4148 diode is connected between the reset pin of Arduino and the output of the 555 timer.
As ...
6
votes
4
answers
1k
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Programming standalone Atmega328p-PU with NE555N timer IC
I know I may sound a little idiotic to ask, but as I have seen in the internet that to program a standalone Atmel chip like that from of the Arduino's, you need 2 22pF ceramic capacitors and a 16mhz ...
5
votes
4
answers
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Why would the resistor be after the LED in this project?
This is project 2 of their official arduino projects book called "Spaceship interface". I understand resistors normally reduce voltage so the LEDs don't burnout but here 5v is coming from either ...
- 55
5
votes
2
answers
17k
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Voltage changes but digitalRead always HIGH
I developed a simple push button project
I used a wemos D1 mini
I connected D3 pin to a pull down 1K resistor.
I used a multimeter to measure D3 pin voltage.
When I push the button, D3 pin voltage ...
- 61
5
votes
1
answer
6k
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Why can't most servos rotate more than around 180°
I was looking how a servomotor works. I realized that a standard servo can only turn up to 180°, but I didn't understand why. Is it because of the potentiometer?
- 117
5
votes
1
answer
187
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Replacement crystal on Uno for cold temperatures
I want to run an arduino out in the cold (-40), and use the serial communication - I believe that the crystal is the weakest link (the one for the serial chip) - however I don't see any drop-in (...
- 197
4
votes
3
answers
1k
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Moving motion sensor?
Long story short, I'm trying to build some form of device that you can wear and it will detect when something moves behind you. I wanted to use PIR sensors for the motion detection, but I have no idea ...
- 41
4
votes
1
answer
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How to burn the bootloader and upload sketches on ATmega328P U (specifically this model)?
Recently I started to learn embedded electronics and C/C++ and for a couple of days I tried and I am still trying to burn a new ATMega328P U bought from Aliexpress. From what I know new ATMega328P's ...
- 61
4
votes
4
answers
343
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How exactly is voltage measured on an Arduino?
How do the analog pins on an Arduino measure voltage?
Do they either measure current and calculate the voltage with Ohm's law? (If so, why can we only read voltage and not current directly?)
Or do ...
- 45
3
votes
3
answers
9k
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7-Segment Common Anode
I accidently bought a "Common Anode" 7-segment display instead of a "Common Cathode".
I understand that the polarity of the leds within the display is 'reversed'. So instead of putting the common pin ...
- 2,715
3
votes
2
answers
403
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How to turn LEDs based on voltage readings?
I am trying to turn LEDs in an LED bridge based on the voltage reading from a power source. when the Voltage is zero nothing is ON and then the LEDs gradually turn ON as increase the voltage connected ...
3
votes
1
answer
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What is difference between analog and digital input and output, and when should i use anlog or digital (input or output)? [closed]
How should i determine whether to use input as analog or digital and same for output too?
- 143
3
votes
1
answer
1k
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Getting the DS18B20 detected and temperature read
I'm quite new with the electronics part of Arduino, but I thought that this was the basic way to get the DS18B20 temperature device hooked up. However, I can't detect it in my program using OneWire ...
- 153
3
votes
2
answers
262
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What is the use of decoupling capacitor?
I dont understand what does the word "decoupling" mean? Where and Why it is used? Can anyone give me a brief idea>?
user4236
3
votes
2
answers
2k
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Sleep mode and watchdog at the same time
Suppose we want to save battery power, and we use sleep mode and also prevent the Arduino from hanging and use the watchdog timer.
The problem is here that when the Arduino goes to sleep the watchdog ...
- 63
3
votes
3
answers
913
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Powering on the PC
I located the two pins that are responsible for powering up the PC. They are connected to the Power On button and one pin has an output of 5 V while the other is the ground.
So far so good, the ...
3
votes
2
answers
92
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AMIS30543 - Library code | Order of pinDirection and pinOut
This piece of code was taken from AMIS30543- Arduino library,
void init(uint8_t slaveSelectPin) {
ssPin = slaveSelectPin;
digitalWrite(ssPin, HIGH);
pinMode(ssPin, OUTPUT);
}
Facts I know
...
- 183
3
votes
2
answers
356
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Weird Voltage Noise
I'm new to this forum, so hello to everyone out there.
So I have an Uno with A0 connected to the positive end of a chain of LEDs (they light up when a motion sensor goes off, clunky, but it works), ...
- 41
3
votes
1
answer
199
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Which voltage regulator should I use? [closed]
A friend and I are working on building a smartwatch on a budget, so it’s a (very) low power project, but we are currently having a problem with the power supplying.
We already chose this board, ...
- 31
3
votes
1
answer
342
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Common Ground Between Arduino and ESP32 - Can I Re-use the ESP32 GND Pin for a Potential Divider
I am trying to connect an ESP32 to an Arduino Mega via Serial Communication using the UART 2 ports on both microcontroller boards.
There needs to be a common ground between the ESP32 and Arduino. ...
- 131
3
votes
0
answers
299
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Sim800l doesn't respond to AT commands
My SIM800L doesn't respond to AT commands. The serial monitor is simply blank.
And the led blinks every 3 seconds which means it is connected to a network
I power it through an LM2596 buck down ...
2
votes
3
answers
211
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What's in an Arduino?
I've been using an Arduino Uno Rev. 3 for a few projects and would like to switch to using a bare Atmega328 chip so I can keep everything on the same board. I've seen the Arduino on breadboard ...
- 123
2
votes
1
answer
190
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Need help figuring out the pinout of a seven segmented display
A friend of mine gave me a 2in. 4 digit seven segment display. But when I sat down and looked at it, I found it has 7 pins on one side and 5 on the other and no indicators of its pinout on it. The ...
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2
votes
2
answers
2k
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Is it possible to increase the voltage on 3.3v output to 5v on an ESP board to power a DC motor? [closed]
I am trying to use an ESP32s controller connected to an RC car DC motor. I found that when using my Arduino this is easily accomplished, and I can see that my output pin produces 5v for the motor to ...
- 43
2
votes
1
answer
1k
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what is the importance of the resistors that connect to push buttons ? can i replace them by wires?
Please, iam a junior in arduino and i want to know what is the importance of the resistors that connect to push buttons? can i replace them by wires?
thanks in advance.
Muhammed R. Hafez
2
votes
2
answers
1k
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As a novice, how do I program my Atmega328p?
I bought a board which the above MCU is the atmega328p. Since I haven't used atmel MCU before, now it's a bit confusing. Are the ATMEGA and STM32 programmers not universal? What programming methods ...
- 21
2
votes
1
answer
904
views
How to calculate required amperage of multiple motors?
I a very simple question about calculating the amperage I need to run 5 stepper motors from my Arduino Uno.
If I have 5 28BYJ-48 stepper motors(which are 5V and are said to require about 240mA each) ...
- 163
2
votes
1
answer
4k
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Does AWG size affect signal from sensors?
Would using a thicker cable like 16 AWG affect the signal being received from an RFID or Ultrasonic sensor?
I understand AWG can make a significant impact on voltage when a thick cable is used over ...
- 45
2
votes
1
answer
3k
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Generating digital positive (+5 V) and negative (-5 V) signal?
Problem in getting -5 V with Arduino.
void setup() {
pinMode(13, OUTPUT);
}
void loop() {
digitalWrite(13, HIGH);
delay(20);
digitalWrite(13, LOW);
delay(20);
}
Above code is generating ...
- 195
2
votes
3
answers
5k
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Industrializing Arduino - 24V io? (Electronics)
I would like to make an arduino board that is capable of handling 24V i/o.
Powering the Arduino would be done through either a linear or switching regulator of some sort. Low amperages, so efficiency ...
- 2,715
2
votes
3
answers
2k
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433MHz transmitter and receiver pair doesnt work
I have a pair of 433 MHz transmitter and receiver:
Transmitter is connected to Arduino pro mini, receiver to Arduino Uno R3.
Output of receiver on serial looks like that (it doesn't change much):
...
- 23
2
votes
1
answer
784
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Newbie question - Biltong Box Project [closed]
I am a newbie to electronics, but I do have experience working with electrical wiring in the UK, so I am comfortable working with 240V reasonably safely. I have also built a camper including all the ...
2
votes
3
answers
436
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Unable to read data with 16 serial clock cycles
I am trying to read data from an AD7314 Temperature Sensor that is connected to an Arduino Uno and output that value onto 6 LEDs also connected to the Arduino Uno board. From the image below, the ...
- 25
2
votes
2
answers
14k
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10k ohm Potentiometer vs 10k ohm Resistor on LCD Display
I'm trying to use a LCD Display with my Arduino, but I don't have a potentiometer and all of the guides I find always require one, usually a 10k ohm potentiometer.
The point is that I'm not very good ...
- 125
2
votes
1
answer
881
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Why does arduino work on usb power?
The arduino website states that the operating voltage of an arduino is 7-12V.
Why does the arduino work powered on just usb then? As usb only outputs 5V and 500ma.
Is it preferable to say run the ...
- 349
2
votes
2
answers
122
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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/ ). ...
2
votes
1
answer
168
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Arduino "Maximum Power point tracker" (MPPT) Problem
I need an IV curve for a solar panel. As far I know, solar-panel and Diode IV curve pretty much the same. Here, I am using diodes(6A10-1) as a solar-panel. Where each Diode voltage drops 0.6volt. I ...
2
votes
2
answers
139
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Arduino UNO socket
As I learnt so far is that Arduino UNO board has a socket for power input. The available power input range is between 7V - 20V, but the optimal usage range is 7V-12V.
Here I am wondering:
---> if ...
2
votes
2
answers
1k
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Powering Atmega328P-Pu externally [closed]
Please I'm new to Arduino and I need assistance. I'm working on a project which makes use of the ultrasonic sensor to make a certain pin high if a certain distance is attained. When I used the USB ...
- 21
2
votes
3
answers
57k
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DHT.h Library not being imported
I am trying to read the humidity and temperature using a DHT11 temperature sensor for an Arduino UNO using the DHT.h library. I have my code below:
#include <DHT.h>
#define dataPin 4
dht DHT;
...
- 121
2
votes
1
answer
534
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Arduino connection to brainwave analyzing module
I want to connect a TGAM module (detecting brainwaves) to an Arduino Uno. I know little of electronics, can someone advise me? To which pin of the Arduino should I connect the TGAM? How to get the ...
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2
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2
answers
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How to calculate the needed voltage and current to supply for Arduino
I have Arduino MEGA and I'm connecting to it 5 servomotors.
{ 3 TowerPro M995
Basic Information
Modulation: Digital
Torque: 4.8V: 130.5 oz-in (9.40 kg-cm)
6.0V: 152.8 oz-in (11.00 kg-cm)
Speed:...
- 37
2
votes
2
answers
504
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How to power on Arduino a few seconds later after GSM module initialization?
I've connected a SIM900A GSM module to Arduino and the circuit works standalone on a 12V power supply. The problem is when I provide the 12V power supply, both GSM module and Arduino starts but the ...
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2
votes
1
answer
168
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How to tell what components are compatible with Arduino Due?
I am interested in using the Arduino Due in an upcoming project, however I am worried that the other shields/components that I need will not be compatible with it, because, according to that link:
...
- 509
2
votes
1
answer
376
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Multiple Arduinos connected to one display
I have one display screen, and 5 Arduino Nanos. They are checking to see if passwords in a text file hash to a specific hash, then display it on the screen when found.
Since they aren't all sending ...
- 19
2
votes
1
answer
4k
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Which relay module to buy and what is the difference between 1 channel and 2 channel relay boards
I wanted to d a simple circuit using Arduino to control the lights in my house. But i do not know which relay module to use my house runs on standard 220v ac.
Can anyone tell me weather this relay ...
2
votes
1
answer
93
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AMIS30543 | DataSheet Understanding CIRCULAR TRANSLATOR TABLE
I was reading the data sheet of AMIS-30543 stepper motor and I didn't understand fully what does this Circular Translator Table means, I have a couple of doubts
What does Circular Translator table ...
- 183
2
votes
1
answer
144
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status whether the switch is connected to arduino or not?
I made a small circuit in which a push-button is connected to Arduino via a pulldown resistor. So, whenever it is pressed it connects to 5V otherwise pulled down to the ground. this is working fine ...
- 21
2
votes
2
answers
2k
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Antenna for ESP32-pico-d4
I am currently playing a bit around with the esp32-pico-4d, it does not have an onboard antenna, so an external antenna is needed, tho I don't know a lot about it so a little help would be appreciated....
- 115
2
votes
1
answer
1k
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NodeMCU Power supply
I got a question about externally powering my NodeMCU V3. It has an onboard voltage regulator (3v3) which breaks out to 3 header pins. Now I want to power 3v3 from an external board. Can I supply 3v3 ...
- 49