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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ATMega I/O maximum current

According to the ATmega328P datasheet, the total current from all I/O pins must not exceed 200mA. Let's say that an Output pin sources 30mA and an Input pin sinks 10mA. The total current should be 30+10=40mA or 30-10=20mA?
user3060854
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Maximum Current?

This is an extremely noobie question, but I have a 5V at 2A power source. This power source is going to be powering 6 Sharp IR distance sensors(20-150cm) and a few other low current consumption sensors(ie Xbee). My question is if it is safe to…
Trexter
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Max current through an Arduino Mega?

How much current can I put through the pins of an Arduino Mega at the same time? The situation: I am building a 7x7x7 LED cube, and my plan was to multiplex in 7 layers of 49 pins, lighting each layer, one at a time. This would mean each pin on the…
Nabushika
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May arduino hang when current is changing over time?

As in title. I've got quadrocopter where Li-Po is parallely connected to motors as well as to arduino. May current driftage cause arduino hangs ?
Scony
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The importance of I/O pin DC current

I am thinking about buying Arduino or Raspberry Pi. I generally know Arduino advantages (fast start-up, low consumption, ADC converters) and disadvantages (low memory, low connectivity, hard programming), but I simply cannot figure out maybe the…
Pygmalion
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Measuring resistance conceptually and in code?

How would I measure resistance over a certain length? In this case the resistance is variable. What I have in my head is that you would output a certain amount of current from one pin, and measure how much comes back from the other. I'm not sure if…
evamvid
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What's wrong with the ACS712 sensor?

I have two ACS712 sensors, one rated for 5A, another—for 20A. I wanted to test how precise they are, and played with different devices (in my case, old PC fans). I copy-pasted the source code from here, and changed only the Vref value as expected,…
Arseni Mourzenko
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How does an analog input pin work?

I have a potentiometer of 10k and I connected it this way: 5v -> potentiometer -> analog input pin of Arduino When I turn the potentiometer I change the resistance of the circuit but in the Arduino documentation they say that an analog pin in INPUT…
Samul
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Measure low current with variable voltage

I want to make a system that always have the same current (about 1ma) in a water with silver electrode. At start it will be purified water so conductivity will be really low. But with time silver particle will be released in water, raising his…
eephyne
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Can I use 5V 1A Adapter to power Arduino UNO?

I have two Adapters, one is rated as Output 12V 500mA (used to power an old modem) and another one is rated as 5V 1A (old mobile phone charger). My question is can use any of these to power my Arduino UNO with a barrel connector? What does it mean…
palash
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calculating the input current

I have been a bit confused about calculating the input current, so I'd be much obliged if someone could help. Let's say that we have a potentiometer connected with an analog input as shown below. In a middle position the resistance of the…
user3060854
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Infrared led and sensor: how it work

I am having a difficult time to understand how an infrared sensor and led work. I have an infrared LED (like the ones you buy anywhere), does it mean that the infrared LED has the frequency os 38khz? I know that infrared light has a wavelegnth, but…
Samul
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