9 years, 11 months ago.

Undefining an Analog input pin

Is it possible to define an AnalogIn only when I need to sample an input then undefine or switch off the ADC to save power?

I'm finding the AnalogIn takes around 100uA that is too much for my use.

Many thanks

2 Answers

9 years, 11 months ago.

Hi Paul,

I don't see any API to disable ADC pin or the module.. have you tried to disable/enable module + clocks, using registers?


Accepted Answer

Hi Martin, I have not looked into this too much for the moment as I'm on site fitting the hardware, but it can wait until next visit for a software update. I will have to look into the possibility of switching embedded modules on and off without a reset. This may seem trivial but 100uA over a period of six months monitoring on battery power does add up. If you do come across a simple register setting, please post here. To be honest in view of the low power features of the KL series MCU's an API for module power control would be an advantage.

posted by Paul Staron 21 May 2014

Sorry Martin I forgot to accept this.

posted by Paul Staron 19 Feb 2019
5 years, 1 month ago.

Did you ever find something to lower that power consumption?

Well I have been sitting here in front of my PC for 4 years and 9 months waiting for an answer and all I get is a question :)

Seriously, I did reduce it to a certain degree, if I remember rightly I disabled some registers in the ADC peripheral and reduced it to around 60uA.

But that was for FRDMKL05z board, I then moved over to the STM32L496 which became available soon after that time and in most cases I could deep sleep that down to 3.5uA so I used this MCU for my low power work.

posted by Paul Staron 19 Feb 2019

Sorry for waking that up ;) I'm using STM32L082 so I guess I'll be able to sleep down to a few µA as well then... Thanks Paul for your update!

posted by Matthieu Labas 19 Feb 2019