tmk
11 years ago
1 changed files with 32 additions and 7 deletions
+ 32
- 7
protocol/serial_soft.c
View File
| * is still useful for negative logic signal like Sun protocol not supported by hardware USART. | * is still useful for negative logic signal like Sun protocol not supported by hardware USART. | ||||
| */ | */ | ||||
| #define WAIT_US (1000000/SERIAL_BAUD) | |||||
| #define WAIT_US (1000000L/SERIAL_BAUD) | |||||
| /* debug for signal timing, see debug pin with oscilloscope */ | /* debug for signal timing, see debug pin with oscilloscope */ | ||||
| #ifdef SERIAL_SOFT_DEBUG | #ifdef SERIAL_SOFT_DEBUG | ||||
| void serial_send(uint8_t data) | void serial_send(uint8_t data) | ||||
| { | { | ||||
| /* signal state: IDLE: ON, START: OFF, STOP: ON, DATA0: OFF, DATA1: ON */ | /* 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_BIT_ORDER_MSB | ||||
| uint8_t mask = 0x80; | uint8_t mask = 0x80; | ||||
| #else | #else | ||||
| uint8_t mask = 0x01; | uint8_t mask = 0x01; | ||||
| #endif | #endif | ||||
| #ifdef SERIAL_PARITY_ODD | |||||
| uint8_t parity = 1; | |||||
| #elif defined(SERIAL_PARITY_EVEN) | |||||
| uint8_t parity = 0; | |||||
| #endif | |||||
| /* start bit */ | |||||
| SERIAL_TXD_OFF(); | |||||
| _delay_us(WAIT_US-2); | |||||
| while (mask) { | while (mask) { | ||||
| if (data&mask) { SERIAL_TXD_ON(); } else { SERIAL_TXD_OFF(); } | |||||
| _delay_us(WAIT_US); | |||||
| if (data&mask) { | |||||
| SERIAL_TXD_ON(); | |||||
| #if defined(SERIAL_PARITY_EVEN) || defined(SERIAL_PARITY_ODD) | |||||
| parity ^= 1; | |||||
| #endif | |||||
| } else { | |||||
| SERIAL_TXD_OFF(); | |||||
| } | |||||
| _delay_us(WAIT_US-2); | |||||
| #ifdef SERIAL_BIT_ORDER_MSB | #ifdef SERIAL_BIT_ORDER_MSB | ||||
| mask >>= 1; | mask >>= 1; | ||||
| #endif | #endif | ||||
| } | } | ||||
| #if defined(SERIAL_PARITY_EVEN) || defined(SERIAL_PARITY_ODD) | |||||
| /* to center of parity bit */ | |||||
| if (parity) { | |||||
| SERIAL_TXD_ON(); | |||||
| } else { | |||||
| SERIAL_TXD_OFF(); | |||||
| } | |||||
| _delay_us(WAIT_US-2); | |||||
| #endif | |||||
| /* stop bit */ | /* stop bit */ | ||||
| SERIAL_TXD_ON(); | SERIAL_TXD_ON(); | ||||
| _delay_us(WAIT_US); | |||||
| _delay_us(WAIT_US-2); | |||||
| } | } | ||||
| /* detect edge of start bit */ | /* detect edge of start bit */ |
Loading…