C3V0 Rev 2, and C3V0+ with Temp/Humidity sensor now available

C3V0 revision 2 is now in stock at MakeDeck, as well as the C3V0+, which has the Silicon Labs Si7021 digital temperature and humidity sensor installed. Please check the product page for changes to the board.

What’s the basis of the 6.9/4.7 in the battery monitoring circuit – voltage divider circuit on input?

Looks like the inverse of 4.7/(4.7+2.2)

Yes, its a voltage divider to bring the LiPo voltage down to a level that the Imp can safely read. You can enable the circuit, read it, and the disable it to keep it from constantly draining power.

What would be a good voltage level to alert on that the battery is running low and should be recharged/replaced? Obviously, consumption rate is a huge factor. My consumption rate is quite low and I’d like to have the device warn me when I should start thinking about the battery.