+volatile u8 last_key; /* the last key registered */
+volatile bool new_key;
+
+/* first 8 from the first row, then 3 from the second row */
+/* keys are 1-9, 0, reset */
+const u8 keymap0[8] = {KEY_1, KEY_2, KEY_3, KEY_4, KEY_5, KEY_6, KEY_7, KEY_8};
+const u8 keymap1[3] = {KEY_9, KEY_0, KEY_RESET};
+
+#define NO_KEY 8
+
+/* reads the keypad and returns the bit number that was turned on in the shift
+ * register (from 0..7). If no bits were turned on, it returns 8 (aka NO_KEY)
+ */
+extern inline u8 keypad_read_row(const u8 row) {
+ u8 i, num;
+
+ if (row)
+ bset((void*)&_io_ports[M6811_PORTD], PORTD_KEYPAD_ROW);
+ else
+ bclr((void*)&_io_ports[M6811_PORTD], PORTD_KEYPAD_ROW);
+
+ spi_enable();
+
+ bset_misc_output(A3800_KEYPAD_STROBE);
+ bclr_misc_output(A3800_KEYPAD_STROBE);
+
+ bclr_misc_output(A3800_DISPLAY_WRITE); /* disable the display clock */
+
+ _io_ports[M6811_SPDR] = 0x55; /* doesn't matter what we send. */
+ while(!(_io_ports[M6811_SPSR]&M6811_SPIF)); /* wait for completion */
+
+ /* SPDR read to clear SPIF flag is performed below: */
+ i = _io_ports[M6811_SPDR];
+
+ num = 0;
+ while (((i & 0x80) == 0) && (num < 8)) {
+ i = i << 1;
+ num++;
+ }
+
+ spi_disable();
+
+ return num;
+}
+
+/* sets last_key to 1..10 or 11 for reset */
+void keypad_read() {
+ /* FIXME: need to do debouncing of some sort? */
+ u8 key;
+ key = keypad_read_row(0);
+ if (NO_KEY == key) {
+ key = keypad_read_row(1);
+ if (key <= 2)
+ key = keymap1[key];
+ else
+ key = 0;
+ } else
+ key = keymap0[key];
+
+ if (key != last_key) {
+ last_key = key;
+ if (key != 0) {
+ new_key = 1;
+ chime_start();
+ }
+ }
+}
+
+bool keypad_pressed() {
+ if (!new_key) return 0;
+ new_key = 0;
+ return 1;
+}
+
+void keypad_init() {
+ last_key = 0;
+ new_key = 0;
+}