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Diffstat (limited to 'protocol')
-rw-r--r--protocol/serial.h1
-rw-r--r--protocol/serial_soft.c57
2 files changed, 42 insertions, 16 deletions
diff --git a/protocol/serial.h b/protocol/serial.h
index 93b9ee9225..bd071bec92 100644
--- a/protocol/serial.h
+++ b/protocol/serial.h
@@ -41,5 +41,6 @@ POSSIBILITY OF SUCH DAMAGE.
/* host role */
void serial_init(void);
uint8_t serial_recv(void);
+void serial_send(uint8_t data);
#endif
diff --git a/protocol/serial_soft.c b/protocol/serial_soft.c
index b7d06b644e..beddc353c0 100644
--- a/protocol/serial_soft.c
+++ b/protocol/serial_soft.c
@@ -51,9 +51,10 @@ POSSIBILITY OF SUCH DAMAGE.
void serial_init(void)
{
SERIAL_RXD_INIT();
+ SERIAL_TXD_INIT();
}
-// RX ring buffer
+/* RX ring buffer */
#define RBUF_SIZE 8
static uint8_t rbuf[RBUF_SIZE];
static uint8_t rbuf_head = 0;
@@ -71,39 +72,63 @@ uint8_t serial_recv(void)
return data;
}
-//ISR(INT2_vect)
+void serial_send(uint8_t data)
+{
+ /* signal state: IDLE: ON, START: OFF, STOP: ON, DATA0: OFF, DATA1: ON */
+ /* start bit */
+ SERIAL_TXD_OFF();
+ _delay_us(WAIT_US);
+
+#ifdef SERIAL_BIT_ORDER_MSB
+ uint8_t mask = 0x80;
+#else
+ uint8_t mask = 0x01;
+#endif
+ while (mask) {
+ if (data&mask) { SERIAL_TXD_ON(); } else { SERIAL_TXD_OFF(); }
+ _delay_us(WAIT_US);
+
+#ifdef SERIAL_BIT_ORDER_MSB
+ mask >>= 1;
+#else
+ mask <<= 1;
+#endif
+ }
+
+ /* stop bit */
+ SERIAL_TXD_ON();
+ _delay_us(WAIT_US);
+}
+
+/* detect edge of start bit */
ISR(SERIAL_RXD_VECT)
{
SERIAL_RXD_INT_ENTER()
uint8_t data = 0;
#ifdef SERIAL_BIT_ORDER_MSB
- uint8_t pos = 0x80;
+ uint8_t mask = 0x80;
#else
- uint8_t pos = 0x01;
+ uint8_t mask = 0x01;
#endif
- // to center of start bit
+ /* to center of start bit */
_delay_us(WAIT_US/2);
do {
- // to center of next bit
+ /* to center of next bit */
_delay_us(WAIT_US);
- if (SERIAL_RXD_PIN&(1<<SERIAL_RXD_BIT)) {
- data |= pos;
+ if (SERIAL_RXD_READ()) {
+ data |= mask;
}
#ifdef SERIAL_BIT_ORDER_MSB
- pos >>= 1;
+ mask >>= 1;
#else
- pos <<= 1;
+ mask <<= 1;
#endif
- } while (pos);
- // to center of stop bit
+ } while (mask);
+ /* to center of stop bit */
_delay_us(WAIT_US);
-#ifdef SERIAL_NEGATIVE_LOGIC
- data = ~data;
-#endif
-
uint8_t next = (rbuf_head + 1) % RBUF_SIZE;
if (next != rbuf_tail) {
rbuf[rbuf_head] = data;