1 /* (CC-BY-NC-SA) ROBIN KRENS - ROBIN @ ROBINKRENS.NL
4 * 2019/8/14 - ROBIN KRENS
8 * Real Time Clock configuration. A Real Time Clock is configured to use
9 * the more accurate external chrystal (LSE) and ticks at exactly
10 * one second. (Can be further calibrated using a tamper pin)
11 * Each clock tick triggers an interrupt and invokes the real time clock
14 * Note: this is not the Cortex M3/M4 SysTick!
22 #include <sys/robsys.h>
25 #include <lib/regfunc.h>
26 #include <lib/tinyprintf.h>
28 #include <drivers/led.h>
29 #include <drivers/tm1637.h>
30 #include <drivers/mk450_joystick.h>
33 /* This handler is invoked each clock tick. I've included two examples
34 * one is writing the clock count to a 4 grid led display. Another is a simple LED blink */
35 void * rtc_handler() {
37 // Real time clock output on a LED display
38 /* int cntvalue = *RTC_CNTL;
39 if (cntvalue < 9999) {
41 unsigned char dn[10] = {0xFC, 0x60, 0xDA, 0xF2, 0x66, 0xB6, 0xBE, 0xE0, 0xFE, 0xF6};
43 int grid0, grid1, grid2, grid3;
45 grid0 = cntvalue % 10;
46 grid1 = ((cntvalue % 100) - grid0) / 10;
47 grid2 = ((cntvalue % 1000) - grid0 - grid1) / 100;
48 grid3 = ((cntvalue % 10000) - grid0 - grid1 - grid2) / 1000;
50 //printf("%d, %d, %d, %d\n", grid0, grid1, grid2, grid3);
52 char current[4] = { dn[grid3], dn[grid2], dn[grid1], dn[grid0] };
54 for (int i = 0; i < 4; i++) {
55 set_grid(i, current[i], false);
62 //uint32_t curr = *RTC_CNTL;
63 //int even = *RTC_CNTL % 2;
64 //(!even) ? led_off() : led_on();
66 printf("X: %x\n", mk450_getx());
67 printf("Y: %x\n", mk450_gety());
69 rclrbit(RTC_CRL, 0); /* clear interrupt flag */
72 /* Enable a periodic interrupt. At each clock count a interrupt is triggered
73 * and consequently the handler is invoked. */
74 static void periodic_intr() {
76 while(!rchkbit(RTC_CRL, 5)); // Check last write is terminated
77 rsetbit(RTC_CRL, 4); // start configure
78 rsetbit(RTC_CRH, 0); // enable periodic (second) interrupt
80 while(!rchkbit(RTC_CRL, 5));
81 rwrite(RTC_PRLL, 0x7FFF); // 0x7FFF equals 1 second clock configuration
82 rclrbit(RTC_CRL, 4); // stop configure
83 while(!rchkbit(RTC_CRL, 5)); // Check last write is terminated
84 rsetbit(NVIC_ISER0, 3); // enable in register vector
87 /* Setup the Real time clock to work with the Low speed external
88 * chrystal (32.768 kHz) */
89 static void setup_rtc() {
91 /* Enable PWREN and BKPEN */
92 rsetbit(RCC_APB1ENR, 28);
93 rsetbit(RCC_APB1ENR, 27);
95 /* Enable access to backup registers and RTC */
98 rsetbit(RCC_BDCR, 0); /* LSE enable */
99 while(!rchkbit(RCC_BDCR, 1)); /* wait for LSE to come up */
101 rsetbitsfrom(RCC_BDCR, 8, 0x1); /* use LSE as RTC source */
102 rsetbit(RCC_BDCR, 15); /* enable RTC */
104 ivt_set_gate(19, rtc_handler, 0); /* setup interrupt handler */
106 //calibrate_rtc(); // uncomment if need, needs TAMPER PIN
108 periodic_intr();// setup periodic interrupt
112 /* Function to calibrate the RTC even more accurate.
113 * Output to a so-called tamper pin. Uncomment if needed */
114 static void calibrate_rtc() {
115 /* rsetbit(BKP_RTCCR, 7); // enable CC0,
116 while(!rchkbit(RTC_CRL, 5)); // Check last write is terminated
118 // Set up and check tamper pin
120 while(!rchkbit(RTC_CRL, 5)); // Check last write is terminated */