Integrate STM32 battery monitoring into AnalogBatteryLevel, supporting
external GPIO ADC pins as well as internal VBAT channel.
Features:
- ADC reading using STM32 LL (Lower Layer) macros supporting external
ADC channels and internal VBAT channel (AVBAT)
- ADC compensation using STM32 LL macros with factory-calibrated VREFINT
(AVREF) for accurate voltage measurement
- LFP battery OCV curve for STM32WL using AVBAT (STM32 VDD absolute
maximum supply voltage 3.9V, direct connection of Li-Po batteries is
not supported)
Internal VBAT channel implemented in:
- Russell
- RAK3172
In these variants, ADC_MULTIPLIER = (1.01f * 3) = 3.30 as there is a
3:1 internal divider (DS13105 Rev 12 §5.3.21), and a bit of tolerance
as the actual 10% spec leads to readings much too high.
Assisted-by: Claude:sonnet-4-5
Signed-off-by: Andrew Yong <me@ndoo.sg>
Andrew YongandGitHub
026213aab7