SparkFun Forums

[rryansilva]

Hi there,

I am trying to power a Rockblock-based project with a 3.7v 4400mAh lipo battery. My thought was to power the Rockblock from the battery using the provided lipo pins and use power from the 5v out to power an Arduino-compatible board. When the Rockblock is powered by the lipo pins, however, there is effectively no current from the 5v out pins. Because it's not an open source item, I can't just pull the Eagle file and see what's going on here. Have I misunderstood the function of the 5v out pins? The datasheet is a marketing document and the Developer's Guide is pretty thin. Thanks for any help.

- Rob

[rryansilva]

I think I answered my own question. Apparently if the On/Off pin is not supplied with a 5V signal, the voltage regulator will not supply power to the 5V out pin. Of course, if nothing is coming out of the 5V out pin, a microcontroller connected to it cannot supply a 5V signal to the On/Off pin. You can't even run 5V straight to the On/Off pin leaving the unit on all the time.

It seems to me that this is a pretty serious limitation on the 5V out pin. Am I missing something?

[jremington]

What are the current limitations of the regulator, or that pin? If not specified, you are taking a chance anyway.
This would be a question for the manufacturer.

Personally, I wouldn't use that pin to power other devices. I would turn on the module only when communications are necessary.