Serial power consumption


#1

Hello!
I am developing a product based on an Electron and I need to reduce as much as possible the power consumption.
During development there are a lot of communication with the Serial over USB to debug the firmware.
What it the power consumption of the Serial? How much energy does a ‘Serial.write()’ use?
In production is it better to switch off the Serial to save some energy or it doesn’t impact on power consumption?

Thanks,
Luca


#2

It depends, and I don’t think Serial would be taking up too much power. Would you be able to use something like deep sleep to reduce power consumption?


#3

@LucaMora, the Serial peripheral is enabled in the system firmware by default. However, there are no metrics that I have seen to gauge the power usage of a Serial.write() command. I agree with @nrobinson2000 that disabling the Serial port will not significantly reduce the amount of power used by the Electron. Have you considered different sleep modes?


#4

Thanks a lot @nrobinson2000 and @peekay123 for your answers!
Yes, I am currently using both sleep and deep sleep to reduce power consumption and I’ve also disabled the on-board LED to save energy.
Of course disabling Serial was not the only strategy that I’ve planned to use to save energy (I’m not so crazy! :laughing:)
Thanks :raised_hands:


#5

My understanding is that keeping the USB Serial connection alive does prevent some parts of the MCU from sleeping when they could be powered down. This is something we’ll probably expose more clearly when we focus on additional support for lower power modes down the road.

Thanks!
David


#6

So in your opinion it is still better to disable Serial connection or it doesn’t have a significant impact on energy consumption?
Moreover, in deep sleep the USB Serial connection isn’t killed and re-opened on startup?
Thanks!


#7

Hi @LucaMora,

So I think right now it doesn’t make a huge difference if it’s on or off, down the road it might save you some power however. Yes in deep sleep basically everything is turned off except the real time clock, so it shouldn’t impact that.

Thanks!
David


#8

Perfect!
You couldn’t be clearer!
Thanks a lot :+1: