Heltec AB01 uA sleep mode...how?

 The document of heltec mentioned an 3.5uA sleep mode(https://heltec-automation-docs.readthedocs.io/en/latest/cubecell/), but you won't be able to achive this using USB connected power.

Nor a lipo battery...since there are LDO on board which can't be sleeped.

here are somedata I found on web:

Power consumption:https://heltec.org/project/htcc-ab01/

  • LoRa Rx Mode: 10mA
  • LoRa 10dBm output: 70mA
  • LoRa 14dBm output: 90mA
  • LoRa 17dBm output: 100mA
  • LoRa 20dBm output: 105mA
  • Sleep Mode (USB powered): 9.6mA
  • Sleep Mode (VBAT/battery powered): 11uA
  • Sleep Mode (3.3V pin powered): 3.5uA

the measurement of 3.5uA is done with an external 3.3V power source directly. Which is not really useful in real application. If their nr is correct.

An other solution is to use a life battery(maybe coin battery will also work.) directly connect to 3.3V pin on board.

The chip can stand upto 3.6V, charged life is about 3.6V. So I did so, but I 1st tried 3.5V life(I did not full charged the battery.)

The board sent data correctly, and did not send out any smoke...

But the ADC used to read battery, can't read any more my external life bat.

according to schematic of heltec:https://resource.heltec.cn/download/CubeCell/HTCC-AB01/HTCC-AB01_SchematicDiagram.pdf



The Vbat and ADC is controlled by a mosfet, so that you don't waste current on divided resistors.

But I measure my board, try to find out where the BR01 0R resistor to attach my Life bat. It's not the same...


On my board, the ADC is on the same side of  Vbat.







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