I have a Vanessa with an attached LiPo (voltage reported at ~ 3.51 v). If I leave the Vanessa attached to the micro USB cable, it runs as expected; disconnect it (leaving only the charged battery attached) and it’s dead to the world. I’m sure there’s some obvious (and clever) power conservation involved, but I haven’t been able to puzzle it out. Does anyone have any suggestions on how to use the Vanessa off of a battery? I’m running the stock demo firmware from GitHub.
3.5v is pretty low for a LiPo cell, it may be browning out under load. Tried charging the battery? ~4.2v is fully charged, 70% ish is generally 3.7-3.8v.
That’s a good idea! The existing battery (from Sparkfun) is rated at 1000 mAh; unattached and under no load, it reads 4.14 volts. I’ll find and charge another and give it a try.
Any recommendations as to battery capacity for the Vanessa?
If you’re seeing it droop from 4.14v to 3.51v under a minimal load then I’d be suspicious about your power input circuits. Which points are you measuring 3.51v between?
We got it sorted. I typically disconnect the onboard UVLO circuitry (shorting pads W20) since most LiPos have it on board, and somehow missed it on this one. Two UVLO’s in a circuit creates some sort of condition that the charging chip doesn’t like.
And I just got to the office after the July 4 holiday, and the new Imp was waiting. Plugged the battery in, downloaded the firmware, and everything’s running fine! Voltage registering 4.20 - perfect!
Thanks again to all and sundry (especially to MakeDeck for sending the replacement).