UNO and MEGA low power

Hello,

I am trying to operate the UNO and MEGA at low power (less than 1 uA at sleep) unsuccessfully.

I managed to operate the ATMEGA382P without peripherals at less than 1uA. I am aware that the mini PRO can be operated at sub uA as well (by not using the USB converter).

Is it possible to program the UNO and MEGA interface USB chip and other peripherals in a way that after the program is downloaded these peripherals are disabled during the run and very low can be achieved?

Thanks,

You will not succeed. You cannot make an Uno or Mega run at low currents since the support IC’s are always powered.

In order to make a pro mini function at low currents, you must remove the LEDs and power directly through the Vin pin.

WattsThat:
In order to make a pro mini function at low currents, you must remove the LEDs and power directly through the Vin pin.

Oops! :astonished:

Power through the "VCC" pin, not the "RAW" ("Vin") pin. If you really want to minimise current draw you also generally need to remove the regulator itself.

You only need to remove the pilot LED's resistor (not the LED as it is easier to put back a resistor than a LED should you need to). Mind you, in a final design you never really need a pilot LED anyway. The "L" LED will only draw current - and light up - if pin 13 is HIGH or INPUT_PULLUP.

Hello,

What parts on Uno and Mega should be removed in order to get low power at sleep (less than few uA)

Radomsky:
Hello,

What parts on Uno and Mega should be removed in order to get low power at sleep (less than few uA)

Just leave the processor, crystal\resonator circuit and decoupling capacitors.

Check the circuit diagram for your particular UNO or Mega to be sure. The actual circuits can vary a bit, especially if you have a 'clone' board, so you do need to be sure your looking at the correct schematic.

Rather than destroy your boards - why not build a minimal circuit with just the processor, crystal and capacitors ( google minimal uno)?

It might be useful to say what your project is aiming to do

hammy:
Rather than destroy your boards - why not build a minimal circuit with just the processor, crystal and capacitors ( google minimal uno)?

Or even simpler/ cheaper/ easier/ quicker/ more durable, get a Pro Mini, remove the resistor for the pilot LED and the regulator. :grinning:

Hello,

Thank you for the advice.

I am trying to build portable wireless (RFM69) data collector.

How can I program a bare uno? Is it possible to run the Arduino IDE on the bare uno and how to do that?
Thanks,

A UNO is an Arduino board with a pile of additional components, the processor is an Atmel ATmega328P.

Lots of info to be found via Google, perhaps search on;

‘Programming a bare ATmega328P’

I am currently working on a low power device. It is not hard to lower the power consumption.
Here are a few things to consider.

  1. Ditch the manifactured device, they can be modified but will still consume memory.
  2. Use a ATMEGA328.
  3. Look a the different boot loader options you have. You can turn off the external crystal and use the internal one.
  4. Read Nick Gammons artical on low power options.
  5. IF your project can go into sleep mode and needs to get sensor readings, power the sensor of a pin.

IF at all worst fails, reach out to me and I will share some code.