SparkFun Forums 

Where electronics enthusiasts find answers.

Questions &/or issues related to products in the Power category should be posted in this forum.
By gcl8a
I'm struggling to figure out why my Pro RF is drawing so much current. I'd like to use it in a battery-powered application, but I'd need to cut the current draw dramatically.

I put the chip on a USB power monitor (with 10 mA resolution) while connected to TTN, and it was drawing a whopping 130 mA. Not sure if the radio is truly put to sleep, I did a test with a variety of boards, blink, and LowPower:

SF SAMD21 Dev:
- blinking: <10 mA
- sleeping: presumably <<10 mA

Adafruit Feather M0 + LoRa:
- blinking: <10 mA
- sleeping: presumably <<10 mA
- running lmic (LoRa) example: < 10 mA (with the occasional spike for the radio)

SF Pro RF:
- blinking: 60 mA !!!
- sleeping: 10 mA !!!
- running lmic library: 70 mA !!!

I've looked over the schematics and other than the LEDs, which should draw a handful of mA at most**, I don't see what could be drawing the current.

Anyone have any idea why this is and what I can do about it? This is a cute, little board, but useless for any practical, battery-powered application in its current state.


**Not sure why SF puts a status LED on a battery-enabled board -- seems a tad silly -- but I can remove the physical draws, if needed.
Are you putting the radio to sleep with not in use? I think if you don't explicitly put it to sleep, it sits there and listens.

Are you taking advantage of the sleep/low-power functions of the microcontroller? In my experience, they don't sleep unless you tell them to.
By gcl8a
For the installation, I'm using the lmic library, which puts the radio to sleep.

But I get high currents when just running blink, which doesn't even touch the radio. Same with sleep. my guess is there's something with the LiPo manager chip that isn't right.