* When running, the "-" button is used for decreasing the output power,
* the "+" button is for increasing it.
* When on the lowest power state, the "-" button switches the system off.
- * TODO: Long "-" button press switches the system off, long "+" button
+ * Long "-" button press switches the system off, long "+" button
* press sets the output power to maximum.
*
* Status LED:
* When powering up by a button press, the LED goes on to provide a visual
* feedback, and is switched off after the button is released.
- * TODO: After a button press, the # of blinks of the LED reflects the
+ * After a button press, the # of blinks of the LED reflects the
* chosen output power level for some time. Afterwards, it displays
* the battery level.
- * TODO: When the battery is completely exhausted, the output power is switched
+ * When the battery is completely exhausted, the output power is switched
* off, the LED keeps blinking for some time, and then the whole system is
* switched off to avoid deep discharge of the battery.
*
#define WAKEUP_POLL 50 // msec
#define WAKEUP_LIMIT 5 // times WAKEUP_POLL
-/* output power levels */
-#define N_STEPS 5
-static unsigned char steps[] = { 60, 85, 121, 171, 242 };
-static unsigned char intensity = 0; // selected power level
-
/* which state (output on or output off) are we measuring now */
static volatile unsigned char adc_type, adc_drop;
#define ADC_RUNAVG_SHIFT 5 // running average shift on batt_on, batt_off
#define MV_TO_ADC8(mV) ((unsigned char)(((uint32_t)(1UL << ADC_RUNAVG_SHIFT) \
* (1024UL * (mV)) \
/ (6UL * ADC_1100MV_VALUE)) >> 8))
-#define BATT_N_LEVELS 3
-static unsigned char batt_levels[BATT_N_LEVELS] = {
- MV_TO_ADC8(3500),
+static unsigned char batt_levels[] = {
+ MV_TO_ADC8(3350),
MV_TO_ADC8(3700),
MV_TO_ADC8(3900),
};
+#define BATT_N_LEVELS (sizeof(batt_levels) / sizeof(batt_levels[0]))
+
+/* output power and PWM calculation */
+#define PWM_TOP 255
+#define PWM_MAX (PWM_TOP - 8) // to allow for ADC "batt_off" measurements
+
+/*
+ * The values in power_levels[] array are voltages at which the load
+ * would give the expected power (we don't have sqrt() function,
+ * so we cannot use mW values directly. They can be calculated as
+ * voltage[V] = sqrt(load_resistance[Ohm] * expected_power[W])
+ * or
+ * voltage[mV] = sqrt(load_resistance[mOhm] * expected_power[mW])
+ *
+ * I use 1.25 W as minimum power, each step is sqrt(2)*previous_step,
+ * so the 5th step is 5 W.
+ */
+static unsigned char power_levels[] = {
+ MV_TO_ADC8(1581), // 1250 mW for 2 Ohm load
+ MV_TO_ADC8(1880), // 1768 mW for 2 Ohm load
+ MV_TO_ADC8(2236), // 2500 mW for 2 Ohm load
+ MV_TO_ADC8(2659), // 3536 mW for 2 Ohm load
+ MV_TO_ADC8(3162), // 5000 mW for 2 Ohm load
+};
+#define N_POWER_LEVELS (sizeof(power_levels) / sizeof(power_levels[0]))
+
+static unsigned char power_level = 0; // selected power level
+static unsigned char power_level_changed; // for visual feedback
+
+#define LED_PWRCHANGE_COUNT 3
+#define LED_BATTEMPTY_COUNT 60
/* timing by WDT */
static volatile unsigned char jiffies, next_clock_tick;
+/* button press duration (in jiffies) */
+#define BUTTON_SHORT_MIN 1
+#define BUTTON_LONG_MIN 10
+
+
/* ========= Analog to Digital Converter (battery voltage) ========== */
static void adc_init()
{
// TCCR1 = _BV(CS10); // clk/1 = 1 MHz
TCCR1 = _BV(CS11) | _BV(CS13); // clk/512 = 2 kHz
GTCCR = _BV(COM1B1) | _BV(PWM1B);
- OCR1C = 255;
+ OCR1C = PWM_TOP;
// OCR1B = steps[0];
OCR1B = 0;
TIMSK = _BV(OCIE1B) | _BV(TOIE1);
hw_setup();
}
-/* ======== Button press detection and handling ===================== */
-static void button_one_pressed()
+/* ============ Status LED blinking =================================== */
+static unsigned char blink_on_time, blink_off_time, n_blinks;
+static unsigned char blink_counter;
+
+static unsigned char battery_level()
+{
+ unsigned char i, adc8;
+
+ // NOTE: we use 8-bit value only, so we don't need lock to protect
+ // us against concurrently running ADC IRQ handler:
+ adc8 = batt_off >> 8;
+
+ for (i = 0; i < BATT_N_LEVELS; i++)
+ if (batt_levels[i] > adc8)
+ break;
+
+ return i;
+}
+
+static void status_led_next_pattern()
{
- if (intensity > 0) {
- pwm_set(steps[--intensity]);
+ static unsigned char battery_exhausted;
+
+ if (power_level_changed) {
+ power_level_changed--;
+ n_blinks = power_level + 1;
+ } else {
+ unsigned char b_level = battery_level();
+ if (b_level) {
+ battery_exhausted = 0;
+ } else if (battery_exhausted) {
+ if (!--battery_exhausted)
+ power_down();
+ } else {
+ battery_exhausted = LED_BATTEMPTY_COUNT;
+ }
+
+ n_blinks = b_level + 1;
+ }
+
+ blink_on_time = 2;
+ blink_off_time = 1;
+ blink_counter = 10;
+}
+
+static void timer_blink()
+{
+ if (blink_counter) {
+ blink_counter--;
+ } else if (!status_led_is_on()) {
+ status_led_on();
+ blink_counter = blink_on_time;
+ } else if (n_blinks) {
+ --n_blinks;
+ status_led_off();
+ blink_counter = blink_off_time;
} else {
- power_down();
+ status_led_next_pattern();
}
}
-static void button_two_pressed()
+/* ======== Button press detection and handling ===================== */
+static void button_pressed(unsigned char button, unsigned char long_press)
{
- if (intensity < N_STEPS-1) {
- pwm_set(steps[++intensity]);
+ // ignore simlultaneous button 1 and 2 press
+ // Note: we set power_level_changed after each button press,
+ // even when the power is at maximum, to provide visual feedback
+ // with status LED.
+ if (long_press) {
+ if (button == 1) {
+ power_down();
+ return;
+ } else if (button == 2) {
+ power_level = N_POWER_LEVELS-1;
+ }
+ } else { // short press
+ if (button == 1) {
+ if (power_level > 0) {
+ --power_level;
+ } else {
+ power_down();
+ return;
+ }
+ } else if (button == 2) {
+ if (power_level < N_POWER_LEVELS-1) {
+ ++power_level;
+ }
+ }
}
+ power_level_changed = LED_PWRCHANGE_COUNT;
+ status_led_next_pattern();
}
static unsigned char button_state, button_state_time;
unsigned char newstate = buttons_pressed();
if (newstate == button_state) {
- if (newstate && button_state_time < 4)
+ if (newstate && button_state_time < BUTTON_LONG_MIN)
++button_state_time;
+
+ if (newstate && button_state_time >= BUTTON_LONG_MIN) {
+ status_led_on();
+ }
return;
}
}
// just released
- switch (button_state) {
- case 1: button_one_pressed();
- break;
- case 2: button_two_pressed();
- break;
- default: // ignore when both are preseed
- break;
- }
+ if (button_state_time >= BUTTON_SHORT_MIN)
+ button_pressed(button_state,
+ button_state_time >= BUTTON_LONG_MIN ? 1 : 0);
button_state = newstate;
+ button_state_time = 0;
}
-/* ============ Status LED blinking =================================== */
-static unsigned char blink_on_time, blink_off_time, n_blinks;
-static unsigned char blink_counter;
-
-static unsigned char battery_level()
+/* ===================== Output power control ======================== */
+static void calculate_power_level()
{
- unsigned char i, adc8;
+ uint32_t pwm;
+ unsigned char batt_on8;
- // NOTE: we use 8-bit value only, so we don't need lock to protect
- // us against concurrently running ADC IRQ handler:
- adc8 = batt_off >> 8;
+ if (battery_level() == 0 || batt_on == 0) {
+ pwm_set(0);
+ // TODO power_down() after some time
+ return;
+ }
- for (i = 0; i < BATT_N_LEVELS; i++)
- if (batt_levels[i] > adc8)
- break;
+ batt_on8 = batt_on >> 8;
- return i;
-}
+ pwm = (uint32_t)PWM_TOP * power_levels[power_level]
+ * power_levels[power_level];
+ pwm /= (uint32_t)batt_on8 * batt_on8;
-static void status_led_next_pattern()
-{
+ if (pwm > PWM_MAX)
+ pwm = PWM_MAX;
- // for now, display the selected intensity
- // n_blinks = intensity + 1;
- n_blinks = battery_level() + 1;
- blink_on_time = 0;
- blink_off_time = 2;
- blink_counter = 10;
-}
+ log_byte(0x10 + power_level);
+ log_byte(batt_on8);
+ log_byte(pwm & 0xFF);
-static void timer_blink()
-{
- if (blink_counter) {
- blink_counter--;
- } else if (status_led_is_on()) {
- status_led_off();
- blink_counter = blink_off_time;
- } else if (n_blinks) {
- --n_blinks;
- status_led_on();
- blink_counter = blink_on_time;
- } else {
- status_led_next_pattern();
- }
+ pwm_set(pwm);
}
int main()
log_word(batt_levels[2]);
log_flush();
#endif
+ log_byte(power_levels[0]);
+ log_byte(power_levels[4]);
+ log_flush();
power_down();
// FIXME: Maybe handle new ADC readings as well?
if (next_clock_tick) {
next_clock_tick = 0;
- timer_check_buttons();
timer_blink();
- if ((jiffies & 0x0F) == 0) {
- unsigned char i;
-
- for (i = 0; i < BATT_N_LEVELS; i++)
- if (batt_levels[i] > batt_off)
- break;
+ // this has to be after the timer_blink() call
+ // to override the status LED during long button press
+ timer_check_buttons();
+ if ((jiffies & 0x0F) == 0) {
+ calculate_power_level();
#if 0
log_byte(0xcc);
log_byte(i);
https://www.fi.muni.cz/~kas/git / heater.git / blobdiff