1 /* 2 * Copyright (c) 2018-2019 Peter Bigot Consulting, LLC 3 * 4 * SPDX-License-Identifier: Apache-2.0 5 */ 6 7 #ifndef APPLICATION_BATTERY_H_ 8 #define APPLICATION_BATTERY_H_ 9 10 /** Enable or disable measurement of the battery voltage. 11 * 12 * @param enable true to enable, false to disable 13 * 14 * @return zero on success, or a negative error code. 15 */ 16 int battery_measure_enable(bool enable); 17 18 /** Measure the battery voltage. 19 * 20 * @return the battery voltage in millivolts, or a negative error 21 * code. 22 */ 23 int battery_sample(void); 24 25 /** A point in a battery discharge curve sequence. 26 * 27 * A discharge curve is defined as a sequence of these points, where 28 * the first point has #lvl_pptt set to 10000 and the last point has 29 * #lvl_pptt set to zero. Both #lvl_pptt and #lvl_mV should be 30 * monotonic decreasing within the sequence. 31 */ 32 struct battery_level_point { 33 /** Remaining life at #lvl_mV. */ 34 uint16_t lvl_pptt; 35 36 /** Battery voltage at #lvl_pptt remaining life. */ 37 uint16_t lvl_mV; 38 }; 39 40 /** Calculate the estimated battery level based on a measured voltage. 41 * 42 * @param batt_mV a measured battery voltage level. 43 * 44 * @param curve the discharge curve for the type of battery installed 45 * on the system. 46 * 47 * @return the estimated remaining capacity in parts per ten 48 * thousand. 49 */ 50 unsigned int battery_level_pptt(unsigned int batt_mV, 51 const struct battery_level_point *curve); 52 53 #endif /* APPLICATION_BATTERY_H_ */ 54
