1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
|
#include "components/battery/BatteryController.h"
#include "components/utility/LinearApproximation.h"
#include "drivers/PinMap.h"
#include <hal/nrf_gpio.h>
#include <nrfx_saadc.h>
#include <algorithm>
#include <cmath>
using namespace Pinetime::Controllers;
Battery* Battery::instance = nullptr;
Battery::Battery() {
instance = this;
nrf_gpio_cfg_input(PinMap::Charging, static_cast<nrf_gpio_pin_pull_t> GPIO_PIN_CNF_PULL_Disabled);
}
void Battery::ReadPowerState() {
isCharging = (nrf_gpio_pin_read(PinMap::Charging) == 0);
isPowerPresent = (nrf_gpio_pin_read(PinMap::PowerPresent) == 0);
if (isPowerPresent && !isCharging) {
isFull = true;
} else if (!isPowerPresent) {
isFull = false;
}
}
void Battery::MeasureVoltage() {
ReadPowerState();
if (isReading) {
return;
}
// Non blocking read
isReading = true;
SaadcInit();
nrfx_saadc_sample();
}
void Battery::AdcCallbackStatic(nrfx_saadc_evt_t const* event) {
instance->SaadcEventHandler(event);
}
void Battery::SaadcInit() {
nrfx_saadc_config_t adcConfig = NRFX_SAADC_DEFAULT_CONFIG;
APP_ERROR_CHECK(nrfx_saadc_init(&adcConfig, AdcCallbackStatic));
nrf_saadc_channel_config_t adcChannelConfig = {.resistor_p = NRF_SAADC_RESISTOR_DISABLED,
.resistor_n = NRF_SAADC_RESISTOR_DISABLED,
.gain = NRF_SAADC_GAIN1_4,
.reference = NRF_SAADC_REFERENCE_INTERNAL,
.acq_time = NRF_SAADC_ACQTIME_40US,
.mode = NRF_SAADC_MODE_SINGLE_ENDED,
.burst = NRF_SAADC_BURST_ENABLED,
.pin_p = batteryVoltageAdcInput,
.pin_n = NRF_SAADC_INPUT_DISABLED};
APP_ERROR_CHECK(nrfx_saadc_channel_init(0, &adcChannelConfig));
APP_ERROR_CHECK(nrfx_saadc_buffer_convert(&saadc_value, 1));
}
void Battery::SaadcEventHandler(nrfx_saadc_evt_t const* p_event) {
static const Utility::LinearApproximation<uint16_t, uint8_t, 6> aprox {{{
{3500, 0}, // Minimum voltage before shutdown (depends on the battery)
{3600, 10}, // Keen point that corresponds to 10%
{3700, 25},
{3750, 50},
{3900, 75},
{4180, 100} // Maximum voltage during charging is 4.21V
}}};
if (p_event->type == NRFX_SAADC_EVT_DONE) {
APP_ERROR_CHECK(nrfx_saadc_buffer_convert(&saadc_value, 1));
// A hardware voltage divider divides the battery voltage by 2
// ADC gain is 1/4
// thus adc_voltage = battery_voltage / 2 * gain = battery_voltage / 8
// reference_voltage is 600mV
// p_event->data.done.p_buffer[0] = (adc_voltage / reference_voltage) * 1024
voltage = p_event->data.done.p_buffer[0] * (8 * 600) / 1024;
uint8_t newPercent = 100;
if (!isFull) {
newPercent = std::min(aprox.GetValue(voltage), isCharging ? uint8_t {99} : uint8_t {100});
}
if (isPowerPresent) {
batteryLowNotified = false;
}
if ((isPowerPresent && newPercent > percentRemaining) || (!isPowerPresent && newPercent < percentRemaining) || firstMeasurement) {
firstMeasurement = false;
percentRemaining = newPercent;
systemTask->PushMessage(System::Messages::BatteryPercentageUpdated);
// warn about low battery when not charging and below threshold
if (BatteryIsLow() && !isPowerPresent && !batteryLowNotified) {
systemTask->PushMessage(System::Messages::LowBattery);
batteryLowNotified = true;
}
}
nrfx_saadc_uninit();
isReading = false;
}
}
void Battery::Register(Pinetime::System::SystemTask* systemTask) {
this->systemTask = systemTask;
}
|
