blob: 9d8a369e27a0dba6dd76704091326bbcd438c116 [file] [log] [blame]
/*
* Copyright (c) 2018-2019 Peter Bigot Consulting, LLC
* Copyright (c) 2019 Nordic Semiconductor ASA
*
* SPDX-License-Identifier: Apache-2.0
*/
#include <math.h>
#include <stdio.h>
#include <stdlib.h>
#include <zephyr/kernel.h>
#include "battery.h"
/** A discharge curve specific to the power source. */
static const struct battery_level_point levels[] = {
/* "Curve" here eyeballed from captured data for the [Adafruit
* 3.7v 2000 mAh](https://www.adafruit.com/product/2011) LIPO
* under full load that started with a charge of 3.96 V and
* dropped about linearly to 3.58 V over 15 hours. It then
* dropped rapidly to 3.10 V over one hour, at which point it
* stopped transmitting.
*
* Based on eyeball comparisons we'll say that 15/16 of life
* goes between 3.95 and 3.55 V, and 1/16 goes between 3.55 V
* and 3.1 V.
*/
{ 10000, 3950 },
{ 625, 3550 },
{ 0, 3100 },
};
static const char *now_str(void)
{
static char buf[16]; /* ...HH:MM:SS.MMM */
uint32_t now = k_uptime_get_32();
unsigned int ms = now % MSEC_PER_SEC;
unsigned int s;
unsigned int min;
unsigned int h;
now /= MSEC_PER_SEC;
s = now % 60U;
now /= 60U;
min = now % 60U;
now /= 60U;
h = now;
snprintf(buf, sizeof(buf), "%u:%02u:%02u.%03u",
h, min, s, ms);
return buf;
}
int main(void)
{
int rc = battery_measure_enable(true);
if (rc != 0) {
printk("Failed initialize battery measurement: %d\n", rc);
return 0;
}
while (true) {
int batt_mV = battery_sample();
if (batt_mV < 0) {
printk("Failed to read battery voltage: %d\n",
batt_mV);
break;
}
unsigned int batt_pptt = battery_level_pptt(batt_mV, levels);
printk("[%s]: %d mV; %u pptt\n", now_str(),
batt_mV, batt_pptt);
/* Burn battery so you can see that this works over time */
k_busy_wait(5 * USEC_PER_SEC);
}
printk("Disable: %d\n", battery_measure_enable(false));
return 0;
}