From eb8094f2fb39dc8ad7b6cd4e79544cb268cb9e16 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?King=20K=C3=A9vin?= <kingkevin@cuvoodoo.info>
Date: Fri, 25 Mar 2016 20:24:46 +0100
Subject: [PATCH] use 4096 Hz square wave

---
 main.c | 41 +++++++++++++++++++++++++++++------------
 1 file changed, 29 insertions(+), 12 deletions(-)

diff --git a/main.c b/main.c
index 83be351..e8deff7 100644
--- a/main.c
+++ b/main.c
@@ -50,7 +50,7 @@ volatile bool button_flag = false; /**< flag set if board user button has been p
 /** @} */
 
 #define TICKS_PER_SECOND 256 /**< the number of ticks in one second */
-#define SQUARE_WAVE_FREQUENCY 1 /**< square wave output frequency from the RTC IC */
+#define SQUARE_WAVE_FREQUENCY 4096 /**< square wave output frequency from the RTC IC */
 /** @defgroup main_ticks ticks per time units
  *  @note these are derived from TICKS_PER_SECOND
  *  @note I have to use type variables because defines would be stored in signed integers, leading to an overflow it later calculations
@@ -223,10 +223,22 @@ static void leds_set(void)
 }
 
 /** @brief set the time on the LEDs
- *  @details this will have an animation where time is incremented until it reaches the provided time
  *  @param[in] time time to set
  */
 static void clock_set_time(uint32_t time)
+{
+	led_off();
+	clock_show_time(time); // set time
+	leds_set(); // set the colors of all LEDs
+	ws2812b_transmit(); // transmit set color
+	led_on();
+}
+
+/** @brief incrementally set the time on the LEDs
+ *  @details this will have an animation where time is incremented until it reaches the provided time
+ *  @param[in] time time to set
+ */
+static void clock_animate_time(uint32_t time)
 {
 	static uint32_t display_time = 0; // the time to display
 	while (display_time<time) {
@@ -239,9 +251,7 @@ static void clock_set_time(uint32_t time)
 		} else { // finally set time
 			display_time = time;
 		}
-		clock_show_time(display_time); // set time (progress)
-		leds_set(); // set the colors of all LEDs
-		ws2812b_transmit(); // transmit set color
+		clock_set_time(display_time); // set time (progress)
 		// delay some time for the animation
 		for (uint32_t i=0; i<400000; i++) {
 			__asm__("nop");
@@ -297,10 +307,11 @@ int main(void)
 		printf("/!\\ RTC oscillator is disabled\n");
 	}
 
-	// get date
+	// get date and time
 	uint16_t* rtc_time = rtc_read_time(); // get RTC time/date
-	uint32_t current_time = rtc_time[2]*ticks_hour+rtc_time[1]*ticks_minute+rtc_time[0]*ticks_second; // the current time
 	printf("current date: %04d-%02d-%02d %02d:%02d:%02d\n", rtc_time[6], rtc_time[5], rtc_time[4], rtc_time[2], rtc_time[1], rtc_time[0]);
+	uint32_t current_time = rtc_time[2]*ticks_hour+rtc_time[1]*ticks_minute+rtc_time[0]*ticks_second; // the current time
+	clock_animate_time(current_time); // set time with animation
 
 	//rtc_write_time(0,52,9,4,23,3,2016);
 	//rtc_oscillator_enable();
@@ -310,6 +321,7 @@ int main(void)
 	button_flag = false; // reset button flag
 	char c = ' '; // to store received character
 	bool char_flag = false; // a new character has been received
+	uint16_t square_wave_prescale = 0; // prescale the square wave output to generate a tick
 	while (true) { // infinite loop
 		while (usart_received) { // data received over UART
 			action = true; // action has been performed
@@ -336,11 +348,16 @@ int main(void)
 		while (square_wave_flag) { // time passed
 			square_wave_flag = false; // reset flag
 			action = true; // action has been performed
-			led_toggle();
-			rtc_time = rtc_read_time(); // get RTC time/date
-			current_time = rtc_time[2]*ticks_hour+rtc_time[1]*ticks_minute+rtc_time[0]*ticks_second; // calculate current time
-			clock_set_time(current_time); // set time
-			printf("it is now %02lu:%02lu:%02lu\n", current_time/ticks_hour, (current_time%ticks_hour)/ticks_minute, (current_time%ticks_minute)/ticks_second); // display time
+			square_wave_prescale = (square_wave_prescale+1)%(SQUARE_WAVE_FREQUENCY/TICKS_PER_SECOND); // increment pre-scale counter
+			if (square_wave_prescale==0) { // pre-scale completed
+				current_time++; // increment time
+				if ((current_time%ticks_second)==0) { // sync on seconds
+					//rtc_time = rtc_read_time(); // get RTC time/date
+					//current_time = rtc_time[2]*ticks_hour+rtc_time[1]*ticks_minute+rtc_time[0]*ticks_second; // calculate current time
+					 printf("it is now %02lu:%02lu:%02lu\n", current_time/ticks_hour, (current_time%ticks_hour)/ticks_minute, (current_time%ticks_minute)/ticks_second); // display time
+				}
+				clock_set_time(current_time); // set time
+			}
 		}
 		if (action) { // go to sleep if nothing had to be done, else recheck for activity
 			action = false;