Switch from internal clock to crystal + button

1 files changed, 41 insertions, 0 deletions

diff --git a/src/display.c b/src/display.c
new file mode 100644
index 0000000..5f2d7f3
--- /dev/null
+++ b/src/display.c
@@ -0,0 +1,41 @@
+#include <avr/io.h>
+#include <stdint.h>
+#include <util/delay.h>
+
+#include "display.h"
+
+// "_gfedcba"
+// Reversed because a-g is mapped to pa0-6. (pa7 is decimal)
+// Complemented because display is common anode
+const uint32_t digit_masks[] = {
+    0b01000000, 0b01111001, 0b00100100, 0b00110000, 0b00011001,
+    0b00010010, 0b00000010, 0b01111000, 0b00000000, 0b00010000,
+};
+
+void write_digit(uint8_t digit) {
+  if (digit > 9 || digit < 0)
+    return;
+  PORTA = digit_masks[digit];
+}
+
+void write_time(uint16_t hour, uint16_t minute) {
+  uint8_t minute_digit1 = minute % 10;
+  uint8_t minute_digit2 = minute / 10;
+  // unsigned short hour_digit1 = hour % 10;
+  // unsigned short hour_digit2 = hour / 10;
+
+#ifdef STUBBED
+  printf("\r:: %d %d", minute_digit2, minute_digit1);
+  fflush(stdout);
+#endif
+
+  write_digit(minute_digit1);
+  PORTA |= (1 << PA7);
+  _delay_ms(10);
+  PORTA &= ~(1 << PA7);
+
+  write_digit(minute_digit2);
+  PORTB |= (1 << PB2);
+  _delay_ms(10);
+  PORTB &= ~(1 << PB2);
+}