X-Git-Url: https://git.ucc.asn.au/?a=blobdiff_plain;f=ROM2%2Fkeypad.c;h=8f50c193dd0a1c239052634363810903a0373373;hb=4ce97d7a672372f9d13383e40397fa6b51d840ca;hp=4105b24fc3a040375592e5f1fc8f1a638b369535;hpb=6f17e7d0c5d83ffca7376a1cff0ea5ff355dba8f;p=uccvend-snackrom.git

diff --git a/ROM2/keypad.c b/ROM2/keypad.c
index 4105b24..8f50c19 100644
--- a/ROM2/keypad.c
+++ b/ROM2/keypad.c
@@ -10,6 +10,11 @@ bool new_key = 0;
 const u8 keymap0[8] = {KEY_8, KEY_7, KEY_6, KEY_5, KEY_4, KEY_3, KEY_2, KEY_1};
 const u8 keymap1[3] = {KEY_RESET, KEY_0, KEY_9};
 
+#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(u8 row) {
 	u8 i, num;
 	if (row)
@@ -23,7 +28,7 @@ extern inline u8 keypad_read_row(u8 row) {
 	while(!(_io_ports[M6811_SPDR]&M6811_SPIE)); /* wait for completion */
 
 	for (i = _io_ports[M6811_SPDR], num = 0;
-		(i&0x1) == 0;
+		(i&0x1 == 0) && (num < 7);
 		i=i>>1, num++);
 
 	return num;
@@ -34,9 +39,12 @@ void keypad_read() {
 	/* FIXME: need to do debouncing of some sort? */
 	u8 key;
 	key = keypad_read_row(0);
-	if (!key) {
+	if (NO_KEY == key) {
 		key = keypad_read_row(1);
-		key = keymap1[key];
+		if (key >= 0 && key <= 2)
+			key = keymap1[key];
+		else
+			key = 0;
 	} else
 		key = keymap0[key];
 
@@ -54,9 +62,3 @@ bool keypad_pressed() {
 	new_key = 0;
 	return 1;
 }
-
-u8 keypad_getkey() {
-	while (!keypad_pressed())
-		keypad_read();
-	return last_key;
-}