SARA SFF R410M Power switch

Hello,

Is there a clean way to attach a power switch to the SARA SFF without disconnecting the battery?

The goal is to be able to turn off the device for prolonged periods but still be able to charge the battery using the onboard USB port.
It can be a momentary switch with software power off or a latching switch, doesn’t really matter for me.

I saw that the One seems to have such a function on pins 4 and 5, but I don’t see it in the SARA SFF schematics.

Thanks,

Alexandre

Hi @Alexandre,

We indeed don’t have the power switch on the SFF board.
You can put the device in sleep while you charge the battery.
http://learn.sodaq.com/boards/Sara_SFF/examples/low_power_sketch/

Best regards,
Jan

Hi @Jan,

Yes, I can. I’ll look into that.
Is there a way to detect that the battery is charging?

Also for long time storage, that not really an option. We store the devices for weeks at a time. And on the low season some might stay unused for 3 month.
We currently resort to removing the batteries, but that’s not very convenient.

Beside adding a latching switch to the battery lead, is there any other way? Even if in involve modifying the boards.

Alexandre

Hi @Alexandre,

I had a chat with our hardware engineer.
We have a solderjumper after the regulator.
If you remove the zero-ohm resistor and replace this with a on/off switch.
Then you can have the same like what use had on the sodaq one.

Best regards,
Jan

Thanks @Jan!

The solderjumper your are talking about is J2, right?

They are not labelled on the boards, so to be sure, is it the one circled in the attached picture?

Hi @Alexandre,

J2 is indeed the one you need.

Best regards,
Jan