diff options
Diffstat (limited to 'protocol/serial_soft.c')
| -rw-r--r-- | protocol/serial_soft.c | 119 |
1 files changed, 102 insertions, 17 deletions
diff --git a/protocol/serial_soft.c b/protocol/serial_soft.c index beddc353c0..e8870bcd79 100644 --- a/protocol/serial_soft.c +++ b/protocol/serial_soft.c @@ -43,15 +43,47 @@ POSSIBILITY OF SUCH DAMAGE. /* * Stupid Inefficient Busy-wait Software Serial - * is still useful for negative logic signal like Sun protocol not supported by hardware USART. + * which is still useful for negative logic signal like Sun protocol + * if it is not supported by hardware UART. + * + * TODO: delay is not accurate enough. Instruction cycle should be counted and inline assemby is needed. */ -#define WAIT_US (1000000/SERIAL_BAUD) +#define WAIT_US (1000000L/SERIAL_SOFT_BAUD) + +#ifdef SERIAL_SOFT_LOGIC_NEGATIVE + #define SERIAL_SOFT_RXD_IN() !(SERIAL_SOFT_RXD_READ()) + #define SERIAL_SOFT_TXD_ON() SERIAL_SOFT_TXD_LO() + #define SERIAL_SOFT_TXD_OFF() SERIAL_SOFT_TXD_HI() +#else + #define SERIAL_SOFT_RXD_IN() !!(SERIAL_SOFT_RXD_READ()) + #define SERIAL_SOFT_TXD_ON() SERIAL_SOFT_TXD_HI() + #define SERIAL_SOFT_TXD_OFF() SERIAL_SOFT_TXD_LO() +#endif + +#ifdef SERIAL_SOFT_PARITY_EVEN + #define SERIAL_SOFT_PARITY_VAL 0 +#elif defined(SERIAL_SOFT_PARITY_ODD) + #define SERIAL_SOFT_PARITY_VAL 1 +#endif + +/* debug for signal timing, see debug pin with oscilloscope */ +#define SERIAL_SOFT_DEBUG +#ifdef SERIAL_SOFT_DEBUG + #define SERIAL_SOFT_DEBUG_INIT() (DDRD |= 1<<7) + #define SERIAL_SOFT_DEBUG_TGL() (PORTD ^= 1<<7) +#else + #define SERIAL_SOFT_DEBUG_INIT() + #define SERIAL_SOFT_DEBUG_TGL() +#endif + void serial_init(void) { - SERIAL_RXD_INIT(); - SERIAL_TXD_INIT(); + SERIAL_SOFT_DEBUG_INIT(); + + SERIAL_SOFT_RXD_INIT(); + SERIAL_SOFT_TXD_INIT(); } /* RX ring buffer */ @@ -60,6 +92,7 @@ static uint8_t rbuf[RBUF_SIZE]; static uint8_t rbuf_head = 0; static uint8_t rbuf_tail = 0; + uint8_t serial_recv(void) { uint8_t data = 0; @@ -72,68 +105,120 @@ uint8_t serial_recv(void) return data; } +int16_t serial_recv2(void) +{ + uint8_t data = 0; + if (rbuf_head == rbuf_tail) { + return -1; + } + + data = rbuf[rbuf_tail]; + rbuf_tail = (rbuf_tail + 1) % RBUF_SIZE; + return data; +} + 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 +#ifdef SERIAL_SOFT_BIT_ORDER_MSB uint8_t mask = 0x80; #else uint8_t mask = 0x01; #endif + + uint8_t parity = 0; + + /* start bit */ + SERIAL_SOFT_TXD_OFF(); + _delay_us(WAIT_US); + while (mask) { - if (data&mask) { SERIAL_TXD_ON(); } else { SERIAL_TXD_OFF(); } + if (data&mask) { + SERIAL_SOFT_TXD_ON(); + parity ^= 1; + } else { + SERIAL_SOFT_TXD_OFF(); + } _delay_us(WAIT_US); -#ifdef SERIAL_BIT_ORDER_MSB +#ifdef SERIAL_SOFT_BIT_ORDER_MSB mask >>= 1; #else mask <<= 1; #endif } +#if defined(SERIAL_SOFT_PARITY_EVEN) || defined(SERIAL_SOFT_PARITY_ODD) + /* to center of parity bit */ + if (parity != SERIAL_SOFT_PARITY_VAL) { + SERIAL_SOFT_TXD_ON(); + } else { + SERIAL_SOFT_TXD_OFF(); + } + _delay_us(WAIT_US); +#endif + /* stop bit */ - SERIAL_TXD_ON(); + SERIAL_SOFT_TXD_ON(); _delay_us(WAIT_US); } /* detect edge of start bit */ -ISR(SERIAL_RXD_VECT) +ISR(SERIAL_SOFT_RXD_VECT) { - SERIAL_RXD_INT_ENTER() + SERIAL_SOFT_DEBUG_TGL(); + SERIAL_SOFT_RXD_INT_ENTER() uint8_t data = 0; -#ifdef SERIAL_BIT_ORDER_MSB + +#ifdef SERIAL_SOFT_BIT_ORDER_MSB uint8_t mask = 0x80; #else uint8_t mask = 0x01; #endif + + uint8_t parity = 0; + /* to center of start bit */ _delay_us(WAIT_US/2); + SERIAL_SOFT_DEBUG_TGL(); do { /* to center of next bit */ _delay_us(WAIT_US); - if (SERIAL_RXD_READ()) { + SERIAL_SOFT_DEBUG_TGL(); + if (SERIAL_SOFT_RXD_IN()) { data |= mask; + parity ^= 1; } -#ifdef SERIAL_BIT_ORDER_MSB +#ifdef SERIAL_SOFT_BIT_ORDER_MSB mask >>= 1; #else mask <<= 1; #endif } while (mask); + +#if defined(SERIAL_SOFT_PARITY_EVEN) || defined(SERIAL_SOFT_PARITY_ODD) + /* to center of parity bit */ + _delay_us(WAIT_US); + if (SERIAL_SOFT_RXD_IN()) { parity ^= 1; } + SERIAL_SOFT_DEBUG_TGL(); +#endif + /* to center of stop bit */ _delay_us(WAIT_US); uint8_t next = (rbuf_head + 1) % RBUF_SIZE; +#if defined(SERIAL_SOFT_PARITY_EVEN) || defined(SERIAL_SOFT_PARITY_ODD) + if ((parity == SERIAL_SOFT_PARITY_VAL) && next != rbuf_tail) { +#else if (next != rbuf_tail) { +#endif rbuf[rbuf_head] = data; rbuf_head = next; } - SERIAL_RXD_INT_EXIT(); + SERIAL_SOFT_RXD_INT_EXIT(); + SERIAL_SOFT_DEBUG_TGL(); } |