main.cpp

00001 #include "mbed.h"
00002 
00003 // Use buttons to select alarm time. Cycle through hours in an incrementing
00004 // fashion using button1, hit select and increment through minutes. Hit
00005 // select one more time to begin the alarm timer.
00006 //
00007 // The Time LEDs will blink in time with the button inputs to show the 
00008 // currently selected alarm time. Once select is hit a second time to begin
00009 // the timer, the LEDs will blink out the configured delay in hours and
00010 // minutes before going into a low power sleep mode.
00011 //
00012 // Once the alarm fires, hitting the select button will turn the alarm off
00013 // until the next time it fires.
00014 //__________________________________________________________________________
00015 // You may also use the RTC (hardware or software through the Time API) to
00016 // set a real world time and set an alarm for a specific timestamp rather
00017 // than on a delay. This would require manually setting the time on each
00018 // reset however, or an internet connection to automatically collect the
00019 // time. See Example <TODO>[HERE] for how to do that.
00020 
00021 // Time constants in seconds
00022 #define HOUR   60 * 60
00023 #define MINUTE 60
00024 
00025 // Globals
00026 DigitalOut alarm_out(D2, 0);
00027 DigitalOut alarm_led(LED_RED, 1);
00028 DigitalOut hour_led(LED_GREEN, 1);
00029 DigitalOut min_led(LED_BLUE, 1);
00030 
00031 InterruptIn inc_time(BUTTON1);
00032 InterruptIn select(BUTTON2);
00033 
00034 LowPowerTicker alarm_event;
00035 
00036 volatile uint64_t delay        = 0;
00037 volatile uint8_t  hour_count   = 0;
00038 volatile uint8_t  min_count    = 0;
00039 volatile uint8_t  select_state = 0;
00040 
00041 // Timer Callbacks
00042 void inc_select(void) {
00043     if (select_state < 2) {
00044         select_state++;
00045     } else {
00046         // Use select button to disable alarm
00047         alarm_out = 0;
00048         alarm_led = 1;
00049     }
00050 }
00051 
00052 void set_time_leds(void) {
00053     if (select_state == 0) {
00054         hour_led = !hour_led;
00055     } else {
00056         min_led = !min_led;
00057     }    
00058 }
00059 
00060 void inc_delay(void) {
00061     if (select_state == 0) {
00062         delay += HOUR;
00063         hour_count++;
00064         hour_led = !hour_led;
00065     } else {
00066         delay += MINUTE;
00067         min_count++;
00068         min_led = !min_led;
00069     }
00070 }
00071 
00072 void trigger_alarm_out(void) {
00073     alarm_out = 1;
00074     alarm_led = 0;
00075 }
00076 
00077 // Main thread
00078 int main() {
00079     // Configure interrupt-in pins (button controls)
00080     select.rise(inc_select);
00081     inc_time.fall(set_time_leds);
00082     inc_time.rise(inc_delay);
00083     
00084     // Sleep while waiting for user input to set the desired delay
00085     while (select_state < 2) { wait_ms(10); }
00086     
00087     // Once the delay has been input, blink back the configured hours and
00088     // minutes selected
00089     for (uint8_t i = 0; i < hour_count * 2; i++) {
00090         hour_led = !hour_led;
00091         wait(0.25f);
00092     }
00093     
00094     for (uint8_t i = 0; i < min_count * 2; i++) {
00095         min_led = !min_led;
00096         wait(0.25f);
00097     }
00098 
00099     // Attach the low power ticker with the configured alarm delay
00100     alarm_event.attach(&trigger_alarm_out, delay);
00101     
00102     // Sleep in the main thread
00103     while (1) { wait(100000); }
00104 }