Added missing source files battery.c and buttons.c

projects/step-up/battery.c

+#include <avr/io.h>
+
+#include "lights.h"
+
+#define BATTERY_ADC_SHIFT	2
+#define RESISTOR_HI	1500	// kOhm
+#define RESISTOR_LO	 100	// kOhm
+/*
+ * The internal 1.1V reference has tolerance from 1.0 to 1.2V
+ * (datasheet, section 19.6). We have to measure the actual value
+ * of our part.
+ */
+#define AREF_1100MV	1060	// mV
+
+static volatile uint16_t battery_adcval;
+static unsigned char initial_readings = 0;
+
+void init_battery()
+{
+	battery_adcval = 0;
+	initial_readings = 5;
+}
+
+unsigned char battery_100mv()
+{
+	/*
+	 * This is tricky: we need to maintain precision, so we first
+	 * multiply adcval by as big number as possible to fit uint16_t,
+	 * then divide to get the final value,
+	 * and finally type-cast it to unsigned char.
+	 * We don't do running average, as the required precision
+	 * is coarse (0.1 V).
+	 */
+	return (unsigned char)
+		((uint16_t)(
+		(battery_adcval >> BATTERY_ADC_SHIFT)
+		* (11                                      // 1.1V
+		* (RESISTOR_HI+RESISTOR_LO)/RESISTOR_LO    // resistor ratio
+		/ 4)) >> 8);                               // divide by 1024
+}
+
+void battery_adc(uint16_t adcval)
+{
+	if (initial_readings) {
+		initial_readings--;
+		battery_adcval = adcval << BATTERY_ADC_SHIFT;
+	} else if (battery_adcval == 0) {
+		battery_adcval = adcval << BATTERY_ADC_SHIFT;
+	} else { // running average
+		battery_adcval += (adcval
+			- (battery_adcval >> BATTERY_ADC_SHIFT));
+	}
+#if 0
+	log_byte(battery_100mv());
+	log_flush();
+#endif
+}
+
+unsigned char battery_gauge()
+{
+	unsigned char b8 = battery_100mv();
+	unsigned char rv;
+
+	if        (b8 < 70) {
+		rv = 1;
+	} else if (b8 < 75) {
+		rv = 2;
+	} else if (b8 < 80) {
+		rv = 3;
+	} else if (b8 < 85) {
+		rv = 4;
+	} else if (b8 < 90) {
+		rv = 5;
+	} else if (b8 < 95) {
+		rv = 6;
+	} else {
+		rv = 7;
+	}
+
+	if (rv == 1 && !initial_readings)
+		set_error(ERR_BATTERY);
+
+#if 0
+	log_byte(0xbb);
+	log_byte(rv);
+	log_flush();
+#endif
+	return rv;
+}

projects/step-up/buttons.c

+#include <avr/io.h>
+#include <avr/interrupt.h>
+#include <avr/sleep.h>
+#include <util/delay.h>
+#include <stdlib.h> // for NULL
+
+#include "lights.h"
+
+#define WAKEUP_LIMIT	5	// times 100 ms
+#define SHORT_PRESS_MIN	10	// in jiffies (100 Hz ticks)
+#define SHORT_PRESS_MAX 50
+#define LONG_PRESS_MIN	100
+static uint16_t button_start;
+static unsigned char prev_state;
+
+void status_led_on_off(unsigned char mode)
+{
+	if (mode)
+		PORTB |= _BV(PORTB0);
+	else
+		PORTB &= ~_BV(PORTB0);
+}
+
+void init_buttons()
+{
+	DDRB &= ~_BV(DDB1);
+	DDRB |= _BV(DDB0);
+	PORTB |= _BV(PORTB1); // enable internal pull-up
+	PORTB &= ~_BV(PORTB0); // status led off
+	GIMSK &= ~_BV(PCIE); // disable pin-change IRQs
+	PCMSK = 0; // disable pin-change IRQs on all pins of port B
+
+	button_start = 0;
+	prev_state   = 0;
+}
+
+void susp_buttons()
+{
+	DDRB &= ~(_BV(DDB1)); // set as input
+	PORTB |= _BV(PORTB1);  // enable internal pull-up
+	PORTB &= ~_BV(PORTB0); // set to zero
+
+	GIMSK |= _BV(PCIE);
+
+	PCMSK = _BV(PCINT1);
+		// disable pin-change IRQs on all pins except PB1
+}
+
+void timer_check_buttons()
+{
+	unsigned char cur = !(PINB & _BV(PINB1));
+	unsigned char prev = prev_state;
+
+	prev_state = cur;
+
+	if (cur && !prev) {                   // --- just pressed ---
+		button_start = jiffies;
+		// set_status_led(button, NULL);
+
+	} else if (cur && prev) {           // --- is still pressed ---
+		uint16_t duration = jiffies - button_start;
+
+		if (duration > LONG_PRESS_MIN) {
+			long_press_start();
+				// acknowledge long press
+		}
+	} else if (!cur && prev) {            // --- just released ---
+		uint16_t duration = jiffies - button_start;
+
+		if (duration > SHORT_PRESS_MIN && duration < SHORT_PRESS_MAX) {
+			short_press();
+		} else if (duration > LONG_PRESS_MIN) {
+			// set_status_led(button, NULL);
+			long_press();
+		}
+		// ignore other button-press durations
+	}
+}
+
+#if 0
+static void handle_brake(unsigned char cur, unsigned char prev)
+{
+	if (cur && !prev) {                   // --- just pressed ---
+		button_start[2] = jiffies;
+	} else if (!cur && prev) {            // --- just released ---
+		button_start[2] = jiffies;
+	} else {                              // --- no change ---
+		uint16_t duration = jiffies - button_start[2];
+
+		if (duration > 6) {
+			if (cur) {
+				if (button_state.brake_working
+					&& !button_state.brake_reported) {
+					button_state.brake_reported = 1;
+					brake_on();
+				}
+			} else {
+				button_state.brake_working = 1;
+				if (button_state.brake_reported) {
+					button_state.brake_reported = 0;
+					brake_off();
+				}
+			}
+			button_start[2] = jiffies - 7; // avoid overflow
+		}
+	}
+}
+#endif
+
+unsigned char buttons_wait_for_release()
+{
+	uint16_t wake_count = 0;
+	unsigned char pin;
+
+	do {
+		if (wake_count++ > WAKEUP_LIMIT)
+			status_led_on_off(1); // inform the user
+
+		_delay_ms(100);
+
+		pin = PINB & _BV(PINB1);
+	} while (!(pin & _BV(PINB1)));
+
+	status_led_on_off(0);
+
+	return wake_count > WAKEUP_LIMIT;
+}
+
+ISR(PCINT0_vect)
+{
+	// empty - let it wake us from sleep, but do nothing else
+}
+