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This tag is for questions regarding powering and/or power consumption of Arduino systems.

This tag is for questions regarding powering and/or power consumption of Arduino systems.

The most common ways to power an Arduino:

  • Wall-wart
  • Battery (with some sort of external circuitry for making sure the voltage is correct.) This is also used sometimes in conjunction with solar panels to act as a "buffer."
  • USB is often used for small projects that are on the breadboard and don't require much power (no motors, etc.).

Power consumption

The Atmega processors in particular are designed to have low power consumption for battery-driven applications. Under the right circumstances you can get power consumption down to 100 nA (0.1 µA). See this chart:

Power consumption chart

The circled area shows 100 nA consumption when running from 3 volts at 25 °C with the watchdog timer (and various other things) disabled.

General techniques you can use to save power are:

  • Run the processor at a lower frequency
  • Run the processor at a lower voltage
  • Turn off unneeded internal modules in software (eg. SPI, I2C, Serial, ADC)
  • Turn off brownout detection
  • Turn off the Analog-to-Digital converter (ADC)
  • Turn off the watchdog timer
  • Put the processor to sleep
  • Don't use inefficient voltage regulators - if possible run directly from batteries
  • Don't use power-hungry displays (eg. indicator LEDs, backlit LCDs)
  • Arrange to wake the processor from sleep only when needed
  • Turn off (with a MOSFET) external devices (eg. SD cards, temperature sensors) until needed

References

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