Olimex's ESP32-DevKit-LiPo Gets Battery Monitoring, Ultra-Low-Power Sleep in New Board Revisions
Revision B to bring new battery-monitoring capabilities, while Revision C drops the deep-sleep power draw to just 0.065mA.
Bulgarian open hardware specialist Olimex is working on a pair of revisions to its ESP32-DevKit-LiPo development board, which adds lithium polymer charging to its earlier ESP32-DevKit design, and has measured an impressive 0.065mA draw in "deep sleep" mode.
Designed to be pin-compatible with the earlier ESP32-DevKit, the ESP32-DevKit-LiPo has proven popular for projects which require integrated battery charging. In the upcoming Revision B variant, currently being prototyped by Olimex, its battery-monitoring capabilities are extended: "If PWR_SENS_E1 jumper is shorted your software can monitor if external power supply is attached or you work on battery," Olimex notes. "If BAT_SEND_E1 jumper is shorted your software can read battery voltage."
The improvements don't stop there: Olimex is also working on a Revision C of the board, which has been designed to drop power consumption as low as possible in order to extend the runtime available from a given battery. The results are impressive: Measured with a +/- 10% accuracy, the ESP32-DevKit-LiPo Revision C is said to draw just 35mA in active mode and 0.065mA in interruptible "deep sleep" with its on-board LED disabled and power coming from a lithium-polymer battery; switching to 5V USB and bringing up the LED raises this to 2mA in deep sleep.
More information on the ESP32-DevKit-LiPo is available from the Olimex store, where it is sold for €9.95 per unit (around $11); the design files for the original Revision A1, meanwhile, can be found on the Olimex GitHub repository under an Apache 2.0 hardware and GPL3 software license.