a6de43e665
Added a driver which uses the nRF52's ADC channel on the VDDH pin to read the battery voltage when using high voltage mode.
43 lines
No EOL
1 KiB
C
43 lines
No EOL
1 KiB
C
/*
|
|
* Copyright (c) 2021 The ZMK Contributors
|
|
*
|
|
* SPDX-License-Identifier: MIT
|
|
*/
|
|
|
|
#include <errno.h>
|
|
#include <drivers/sensor.h>
|
|
|
|
#include "battery_common.h"
|
|
|
|
int battery_channel_get(const struct battery_value *value, enum sensor_channel chan,
|
|
struct sensor_value *val_out) {
|
|
switch (chan) {
|
|
case SENSOR_CHAN_GAUGE_VOLTAGE:
|
|
val_out->val1 = value->millivolts / 1000;
|
|
val_out->val2 = (value->millivolts % 1000) * 1000U;
|
|
break;
|
|
|
|
case SENSOR_CHAN_GAUGE_STATE_OF_CHARGE:
|
|
val_out->val1 = value->state_of_charge;
|
|
val_out->val2 = 0;
|
|
break;
|
|
|
|
default:
|
|
return -ENOTSUP;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
uint8_t lithium_ion_mv_to_pct(int16_t bat_mv) {
|
|
// Simple linear approximation of a battery based off adafruit's discharge graph:
|
|
// https://learn.adafruit.com/li-ion-and-lipoly-batteries/voltages
|
|
|
|
if (bat_mv >= 4200) {
|
|
return 100;
|
|
} else if (bat_mv <= 3450) {
|
|
return 0;
|
|
}
|
|
|
|
return bat_mv * 2 / 15 - 459;
|
|
} |