Diff: main.cpp

Revision:

0:d31de7b879e3

Child:

1:aa3c38eaaeff

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp	Wed Oct 03 21:25:47 2018 +0000
@@ -0,0 +1,104 @@
+#include "mbed.h"
+
+// Use buttons to select alarm time. Cycle through hours in an incrementing
+// fashion using button1, hit select and increment through minutes. Hit
+// select one more time to begin the alarm timer.
+//
+// The Time LEDs will blink in time with the button inputs to show the 
+// currently selected alarm time. Once select is hit a second time to begin
+// the timer, the LEDs will blink out the configured delay in hours and
+// minutes before going into a low power sleep mode.
+//
+// Once the alarm fires, hitting the select button will turn the alarm off
+// until the next time it fires.
+//__________________________________________________________________________
+// You may also use the RTC (hardware or software through the Time API) to
+// set a real world time and set an alarm for a specific timestamp rather
+// than on a delay. This would require manually setting the time on each
+// reset however, or an internet connection to automatically collect the
+// time. See Example <TODO>[HERE] for how to do that.
+
+// Time constants in seconds
+#define HOUR   60 * 60
+#define MINUTE 60
+
+// Globals
+DigitalOut alarm_out(D0);
+DigitalOut alarm_led(LED_RED, 1);
+DigitalOut hour_led(LED_GREEN, 1);
+DigitalOut min_led(LED_BLUE, 1);
+
+InterruptIn inc_time(BUTTON1);
+InterruptIn select(BUTTON2);
+
+LowPowerTicker alarm_event;
+
+volatile uint64_t delay        = 0;
+volatile uint8_t  hour_count   = 0;
+volatile uint8_t  min_count    = 0;
+volatile uint8_t  select_state = 0;
+
+// Timer Callbacks
+void inc_select(void) {
+    if (select_state < 2) {
+        select_state++;
+    } else {
+        // Use select button to disable alarm
+        alarm_out = !alarm_out;
+        alarm_led = !alarm_led;
+    }
+}
+
+void set_time_leds(void) {
+    if (select_state == 0) {
+        hour_led = !hour_led;
+    } else {
+        min_led = !min_led;
+    }    
+}
+
+void inc_delay(void) {
+    if (select_state == 0) {
+        delay += HOUR;
+        hour_count++;
+        hour_led = !hour_led;
+    } else {
+        delay += MINUTE;
+        min_count++;
+        min_led = !min_led;
+    }
+}
+
+void trigger_alarm_out(void) {
+    alarm_out = 0;
+    alarm_led = 0;
+}
+
+// Main thread
+int main() {
+    // Configure interrupt-in pins (button controls)
+    select.rise(inc_select);
+    inc_time.fall(set_time_leds);
+    inc_time.rise(inc_delay);
+    
+    // Sleep while waiting for user input to set the desired delay
+    while (select_state < 2) { __WFI(); }
+    
+    // Once the delay has been input, blink back the configured hours and
+    // minutes selected
+    for (uint8_t i = 0; i < hour_count * 2; i++) {
+        hour_led = !hour_led;
+        wait(0.25f);
+    }
+    
+    for (uint8_t i = 0; i < min_count * 2; i++) {
+        min_led = !min_led;
+        wait(0.25f);
+    }
+
+    // Attach the low power ticker with the configured alarm delay
+    alarm_event.attach(&trigger_alarm_out, delay);
+    
+    // Sleep while waiting for the lowpower ticker interrupt to fire the alarm
+    while (true) { __WFI(); }
+}
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