/*
* 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)
-#if 1
-#define WAIT_TICK (1000000/SERIAL_BAUD)
-#define WAIT4(tick) _delay_us(tick)
+#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 WAIT_TICK ((16000000/SERIAL_BAUD)/4 - 5)
-static inline void WAIT4(uint8_t tick)
-{
- __asm__ __volatile__ (
- "1: dec %0" "\n\t"
- "nop" "\n\t"
- "brne 1b"
- :
- : "r" (tick)
- );
-}
+ #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 */
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)
{
-PORTD ^= 1<<7;
- 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
-#ifdef SERIAL_PARITY_ODD
uint8_t parity = 0;
-#else
- uint8_t parity = 1;
-#endif
/* to center of start bit */
- //_delay_us(WAIT_US/2);
- WAIT4(WAIT_TICK/2);
-PORTD ^= 1<<7;
+ _delay_us(WAIT_US/2);
+ SERIAL_SOFT_DEBUG_TGL();
do {
/* to center of next bit */
- //_delay_us(WAIT_US);
- WAIT4(WAIT_TICK);
+ _delay_us(WAIT_US);
-PORTD ^= 1<<7;
- 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);
- WAIT4(WAIT_TICK);
- if (SERIAL_RXD_READ()) { parity ^= 1; }
-PORTD ^= 1<<7;
+ _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);
- WAIT4(WAIT_TICK);
+ _delay_us(WAIT_US);
uint8_t next = (rbuf_head + 1) % RBUF_SIZE;
- //if (parity && next != rbuf_tail) {
+#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();
-PORTD ^= 1<<7;
+ SERIAL_SOFT_RXD_INT_EXIT();
+ SERIAL_SOFT_DEBUG_TGL();
}