diff options
Diffstat (limited to 'protocol')
| -rw-r--r-- | protocol/serial.h | 1 | ||||
| -rw-r--r-- | protocol/serial_soft.c | 57 |
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; |