X-Git-Url: http://git.droids-corp.org/?a=blobdiff_plain;f=main.c;h=c89b6373065d32ce23503e9ae27fab192238ca96;hb=5cf087f7d27e0c7e565a1a7591020cedb6a9bcbf;hp=657e54d35fe67c4279924b24e83a2f8564d61f3e;hpb=face7352ff4e497c17590266455bda126f35d842;p=protos%2Frc_servos.git

diff --git a/main.c b/main.c
index 657e54d..c89b637 100644
--- a/main.c
+++ b/main.c
@@ -21,10 +21,13 @@ static struct servo servo_table[] = {
 };
 #define NB_SERVO (sizeof(servo_table)/sizeof(*servo_table))
 
-register uint8_t bypass asm("r2");
-register uint8_t done asm("r3");
-register uint8_t portval asm("r4");
-register uint8_t rxidx asm("r5");
+static volatile uint8_t bypass;
+static volatile uint8_t done;
+static volatile uint8_t portval;
+static volatile uint8_t rxidx;
+
+#define BYPASS_ENABLE 14
+#define BYPASS_DISABLE 15
 
 /*
  * SPI protocol:
@@ -37,22 +40,24 @@ register uint8_t rxidx asm("r5");
  * Command 14 is to enable bypass mode.
  * Command 15 is to disable bypass mode.
  */
-register union {
+static volatile union {
 	uint8_t u8;
 	struct {
-		uint16_t zero:1;
-		uint16_t cmd_num:4;
-		uint16_t val_msb:3;
+		/* inverted: little endian */
+		uint8_t val_msb:3;
+		uint8_t cmd_num:4;
+		uint8_t zero:1;
 	};
-} byte0 asm("r6");
+} byte0;
 
-register union {
+static volatile union {
 	uint8_t u8;
 	struct {
-		uint8_t one:1;
+		/* inverted: little endian */
 		uint8_t val_lsb:7;
+		uint8_t one:1;
 	};
-} byte1 asm("r7");
+} byte1;
 
 SIGNAL(TIMER1_COMPA_vect)
 {
@@ -94,10 +99,10 @@ static void poll_spi(void)
 			val += byte1.val_lsb;
 			servo_table[byte0.cmd_num].command = val;
 		}
-		else if (byte0.cmd_num == 14) {
+		else if (byte0.cmd_num == BYPASS_ENABLE) {
 			bypass = 1;
 		}
-		else if (byte0.cmd_num == 15) {
+		else if (byte0.cmd_num == BYPASS_DISABLE) {
 			bypass = 0;
 		}
 	}
@@ -157,6 +162,7 @@ int main(void)
 
 	sei();
 
+	bypass = 1;
 	while (1) {
 		t = TCNT0;
 		for (i = 0; i < NB_SERVO; i++) {