2 #include <util/delay.h>
9 void battery_init(void)
12 battery_led(LED_ON); _delay_ms(500);
13 battery_led(LED_OFF); _delay_ms(500);
14 battery_led(LED_ON); _delay_ms(500);
15 battery_led(LED_OFF); _delay_ms(500);
16 // LED indicates charger status
17 battery_led(LED_CHARGER);
19 // ADC setting for voltage monitor
20 // Ref:2.56V band-gap, Input:ADC0(PF0), Prescale:128(16MHz/128=125KHz)
21 ADMUX = (1<<REFS1) | (1<<REFS0);
22 ADCSRA = (1<<ADPS2) | (1<<ADPS1) | (1<<ADPS0);
26 // Indicator for battery
27 void battery_led(battery_led_t val)
29 if (val == LED_TOGGLE) {
33 } else if (val == LED_ON) {
34 // On overriding charger status
37 } else if (val == LED_OFF) {
38 // Off overriding charger status
42 // Display charger status
48 bool battery_charging(void)
50 if (!(USBSTA&(1<<VBUS))) return false;
53 // HiZ: Shutdown/No Battery
57 // preserve last register status
58 uint8_t ddrf_prev = DDRF;
59 uint8_t portf_prev = PORTF;
65 bool charging = PINF&(1<<5) ? false : true;
67 // restore last register status
68 DDRF = (DDRF&~(1<<5)) | (ddrf_prev&(1<<5));
69 PORTF = (PORTF&~(1<<5)) | (portf_prev&(1<<5));
74 // Returns voltage in mV
75 uint16_t battery_voltage(void)
77 volatile uint16_t bat;
78 //ADCSRA |= (1<<ADEN);
80 // discard first result
82 while (ADCSRA & (1<<ADSC)) ;
85 // discard second result
87 while (ADCSRA & (1<<ADSC)) ;
91 while (ADCSRA & (1<<ADSC)) ;
94 //ADCSRA &= ~(1<<ADEN);
96 return (bat - BATTERY_ADC_OFFSET) * BATTERY_ADC_RESOLUTION;
99 static bool low_voltage(void) {
100 static bool low = false;
101 uint16_t v = battery_voltage();
102 if (v < BATTERY_VOLTAGE_LOW_LIMIT) {
104 } else if (v > BATTERY_VOLTAGE_LOW_RECOVERY) {
110 battery_status_t battery_status(void)
112 if (USBSTA&(1<<VBUS)) {
114 return battery_charging() ? CHARGING : FULL_CHARGED;
117 return low_voltage() ? LOW_VOLTAGE : DISCHARGING;