Arduino Stack Exchange
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Questions tagged [current]

Use this tag to refer to the volume of electricity traveling through any given wire at any given time. It is measured in amps.

194 questions
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Is there a limit on how much current a pin can sink?

I've been experimenting with an 8x8 LED matrix controlled by an Arduino Uno. As I think is typical, the matrix uses a common anode for each row, and a common cathode for each column. At the moment, I've got all the matrix pins connected directly to…
Peter Bloomfield
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1 answer

A digital I/O pin as ground

I want an I/O pin to return current in a circuit, similarly to the function of ground. Which of these will achieve what I require? pinMode(pinnumber, OUTPUT) digitalWrite(pinnumber, LOW) or pinMode(pinnumber, input)
rajat
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2 answers

Max current of Vin and 5V pin on Arduino Nano

What is the max current of the Arduino Nano's Vin (30) and 5V (27) pins?
Morgoth
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6
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1 answer

PWM signaling with Arduinos: What is the reason for the ground connection?

This may sound like a very dumb question and I apologise in advance. I've gone through reading about PWM and working on some example sketches to control PC fan speeds using PWM and Arduino. In all documents I read, it is mentioned that "PWM is a…
Phil
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5
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1 answer

Will 5V 2A current input to the power port kill my Arduino?

I want to power my Arduino with a mobile charger, the out put is 5V 2A, will it kill my Arduino? And what's the max input current as power source?
Yusuf Been Hashem
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5
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2 answers

Arduino potentiometer example: what limits the current?

I have a question regarding potentiometer example: https://www.arduino.cc/en/Tutorial/AnalogReadSerial If I turn the potentiometer to the marginal position and have 5V at A0 (and almost zero resistance at the pot), what limits the current flowing…
Denis Kulagin
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5
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1 answer

ArduinoMEGA: 64 digital inputs cause random digitalRead values

I have 64 hall effect sensors (magnetic field sensors) (DRV5023AJQLPG) connected to an Arduino MEGA 2560. For that, I use 48 digital pins and 16 analog pins as digital input pins. The program in the Arduino continuously reads out those 64 digital…
Edo Paulus
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4
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3 answers

Powering up LED strip - How many amps?

I want my Arduino to drive a LED strip. The LED strip in particular is the 3528 non-waterproof type. To power this up, I need a 12V power supply. My LED strip is going to be 5 meters. Now my questions are: Is it important on how many amps, my…
user1584421
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4
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1 answer

Methods to prevent Accelerometer values changing from current spikes

I've connected an Arduino Uno to a MAX7219 IC, which is connected to only one standard 8x8 LED matrix, and an ADXL355 3-axis accelerometer. I use the matrix initially, and turn on all LEDs, while taking the "rest" values for the accelerometer to…
naiveai
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4
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2 answers

Arduino Power - DC adapter

I have a 12V 2.5 ampere Dc adapter.Can i use it to power arduino uno board? It says on the arduino website that i can use 9-12V and upto 1 ampere. I am concerned with current limit here..
Awais Saifi
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4
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2 answers

Does the square-wave nature of PWM dictate how much resistance you need?

I think the answer is yes, but I wanted to ask the question anyway for future common reference. And to check my understanding. Say I want to power 10 LEDs with PWM with my Mega 2560. I have a bunch of 200 ohm resistors. I know the Mega and most…
Aurast
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4
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1 answer

Which device to use to measure AC current using Arduino?

I'm building a home automation product and want to measure AC current using Arduino (as of now). I've used ACS712 5A Hall Effect Current module but there's a lot of electrical noise and also the accuracy is not good. There's a lot of deflection in…
Sshankar7
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3
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1 answer

What is the maximum "wattage" can be pushed into an ATMega328 ADC pins?

I was doing some Ohm's Law calculations to calculate the voltage output from a 2-resistor voltage divider, the input will be with a maximum of 12 volts, I want the ATMega328 to measure that voltage, so I simply thought of putting two resistors in…
Shams M.Monem
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3
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3 answers

Arduino Pro Mini maximal and recommended current per pin

In Arduino Pro Mini (3.3V) specs indicated the maximal and recommended current per pin, 40mA and 20mA respectively. Does these values means input current (i.e. safe input current Arduino can handle) or output current?
minto
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3
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Measuring voltage from -12 to +12 VDC

I'm making a -12 to +12V DC regulated power supply, on which I want to measure voltage and current with Arduino (through a voltage divider, of course). I'm not sure, how to either detect nor measure negative voltage. I could "detect" it via a…
Jakey
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