/* * WARNING: be careful changing this code, it is very timing dependent * * 2018-10-28 checked * avr-gcc 4.9.2 * avr-gcc 5.4.0 * avr-gcc 7.3.0 */ #ifndef F_CPU #define F_CPU 16000000 #endif #include <avr/io.h> #include <avr/interrupt.h> #include <util/delay.h> #include <stddef.h> #include <stdbool.h> #include "serial.h" #ifdef SOFT_SERIAL_PIN #ifdef __AVR_ATmega32U4__ // if using ATmega32U4 I2C, can not use PD0 and PD1 in soft serial. #ifdef USE_I2C #if SOFT_SERIAL_PIN == D0 || SOFT_SERIAL_PIN == D1 #error Using ATmega32U4 I2C, so can not use PD0, PD1 #endif #endif #if SOFT_SERIAL_PIN >= D0 && SOFT_SERIAL_PIN <= D3 #define SERIAL_PIN_DDR DDRD #define SERIAL_PIN_PORT PORTD #define SERIAL_PIN_INPUT PIND #if SOFT_SERIAL_PIN == D0 #define SERIAL_PIN_MASK _BV(PD0) #define EIMSK_BIT _BV(INT0) #define EICRx_BIT (~(_BV(ISC00) | _BV(ISC01))) #define SERIAL_PIN_INTERRUPT INT0_vect #elif SOFT_SERIAL_PIN == D1 #define SERIAL_PIN_MASK _BV(PD1) #define EIMSK_BIT _BV(INT1) #define EICRx_BIT (~(_BV(ISC10) | _BV(ISC11))) #define SERIAL_PIN_INTERRUPT INT1_vect #elif SOFT_SERIAL_PIN == D2 #define SERIAL_PIN_MASK _BV(PD2) #define EIMSK_BIT _BV(INT2) #define EICRx_BIT (~(_BV(ISC20) | _BV(ISC21))) #define SERIAL_PIN_INTERRUPT INT2_vect #elif SOFT_SERIAL_PIN == D3 #define SERIAL_PIN_MASK _BV(PD3) #define EIMSK_BIT _BV(INT3) #define EICRx_BIT (~(_BV(ISC30) | _BV(ISC31))) #define SERIAL_PIN_INTERRUPT INT3_vect #endif #elif SOFT_SERIAL_PIN == E6 #define SERIAL_PIN_DDR DDRE #define SERIAL_PIN_PORT PORTE #define SERIAL_PIN_INPUT PINE #define SERIAL_PIN_MASK _BV(PE6) #define EIMSK_BIT _BV(INT6) #define EICRx_BIT (~(_BV(ISC60) | _BV(ISC61))) #define SERIAL_PIN_INTERRUPT INT6_vect #else #error invalid SOFT_SERIAL_PIN value #endif #else #error serial.c now support ATmega32U4 only #endif //////////////// for backward compatibility //////////////////////////////// #ifndef SERIAL_USE_MULTI_TRANSACTION /* --- USE Simple API (OLD API, compatible with let's split serial.c) */ #if SERIAL_SLAVE_BUFFER_LENGTH > 0 uint8_t volatile serial_slave_buffer[SERIAL_SLAVE_BUFFER_LENGTH] = {0}; #endif #if SERIAL_MASTER_BUFFER_LENGTH > 0 uint8_t volatile serial_master_buffer[SERIAL_MASTER_BUFFER_LENGTH] = {0}; #endif uint8_t volatile status0 = 0; SSTD_t transactions[] = { { (uint8_t *)&status0, #if SERIAL_MASTER_BUFFER_LENGTH > 0 sizeof(serial_master_buffer), (uint8_t *)serial_master_buffer, #else 0, (uint8_t *)NULL, #endif #if SERIAL_SLAVE_BUFFER_LENGTH > 0 sizeof(serial_slave_buffer), (uint8_t *)serial_slave_buffer #else 0, (uint8_t *)NULL, #endif } }; void serial_master_init(void) { soft_serial_initiator_init(transactions, TID_LIMIT(transactions)); } void serial_slave_init(void) { soft_serial_target_init(transactions, TID_LIMIT(transactions)); } // 0 => no error // 1 => slave did not respond // 2 => checksum error int serial_update_buffers() { int result; result = soft_serial_transaction(); return result; } #endif // end of Simple API (OLD API, compatible with let's split serial.c) //////////////////////////////////////////////////////////////////////////// #define ALWAYS_INLINE __attribute__((always_inline)) #define NO_INLINE __attribute__((noinline)) #define _delay_sub_us(x) __builtin_avr_delay_cycles(x) // parity check #define ODD_PARITY 1 #define EVEN_PARITY 0 #define PARITY EVEN_PARITY #ifdef SERIAL_DELAY // custom setup in config.h // #define TID_SEND_ADJUST 2 // #define SERIAL_DELAY 6 // micro sec // #define READ_WRITE_START_ADJUST 30 // cycles // #define READ_WRITE_WIDTH_ADJUST 8 // cycles #else // ============ Standard setups ============ #ifndef SELECT_SOFT_SERIAL_SPEED #define SELECT_SOFT_SERIAL_SPEED 1 // 0: about 189kbps // 1: about 137kbps (default) // 2: about 75kbps // 3: about 39kbps // 4: about 26kbps // 5: about 20kbps #endif #if __GNUC__ < 6 #define TID_SEND_ADJUST 14 #else #define TID_SEND_ADJUST 2 #endif #if SELECT_SOFT_SERIAL_SPEED == 0 // Very High speed #define SERIAL_DELAY 4 // micro sec #if __GNUC__ < 6 #define READ_WRITE_START_ADJUST 33 // cycles #define READ_WRITE_WIDTH_ADJUST 3 // cycles #else #define READ_WRITE_START_ADJUST 34 // cycles #define READ_WRITE_WIDTH_ADJUST 7 // cycles #endif #elif SELECT_SOFT_SERIAL_SPEED == 1 // High speed #define SERIAL_DELAY 6 // micro sec #if __GNUC__ < 6 #define READ_WRITE_START_ADJUST 30 // cycles #define READ_WRITE_WIDTH_ADJUST 3 // cycles #else #define READ_WRITE_START_ADJUST 33 // cycles #define READ_WRITE_WIDTH_ADJUST 7 // cycles #endif #elif SELECT_SOFT_SERIAL_SPEED == 2 // Middle speed #define SERIAL_DELAY 12 // micro sec #define READ_WRITE_START_ADJUST 30 // cycles #if __GNUC__ < 6 #define READ_WRITE_WIDTH_ADJUST 3 // cycles #else #define READ_WRITE_WIDTH_ADJUST 7 // cycles #endif #elif SELECT_SOFT_SERIAL_SPEED == 3 // Low speed #define SERIAL_DELAY 24 // micro sec #define READ_WRITE_START_ADJUST 30 // cycles #if __GNUC__ < 6 #define READ_WRITE_WIDTH_ADJUST 3 // cycles #else #define READ_WRITE_WIDTH_ADJUST 7 // cycles #endif #elif SELECT_SOFT_SERIAL_SPEED == 4 // Very Low speed #define SERIAL_DELAY 36 // micro sec #define READ_WRITE_START_ADJUST 30 // cycles #if __GNUC__ < 6 #define READ_WRITE_WIDTH_ADJUST 3 // cycles #else #define READ_WRITE_WIDTH_ADJUST 7 // cycles #endif #elif SELECT_SOFT_SERIAL_SPEED == 5 // Ultra Low speed #define SERIAL_DELAY 48 // micro sec #define READ_WRITE_START_ADJUST 30 // cycles #if __GNUC__ < 6 #define READ_WRITE_WIDTH_ADJUST 3 // cycles #else #define READ_WRITE_WIDTH_ADJUST 7 // cycles #endif #else #error invalid SELECT_SOFT_SERIAL_SPEED value #endif /* SELECT_SOFT_SERIAL_SPEED */ #endif /* SERIAL_DELAY */ #define SERIAL_DELAY_HALF1 (SERIAL_DELAY/2) #define SERIAL_DELAY_HALF2 (SERIAL_DELAY - SERIAL_DELAY/2) #define SLAVE_INT_WIDTH_US 1 #ifndef SERIAL_USE_MULTI_TRANSACTION #define SLAVE_INT_RESPONSE_TIME SERIAL_DELAY #else #define SLAVE_INT_ACK_WIDTH_UNIT 2 #define SLAVE_INT_ACK_WIDTH 4 #endif static SSTD_t *Transaction_table = NULL; static uint8_t Transaction_table_size = 0; inline static void serial_delay(void) ALWAYS_INLINE; inline static void serial_delay(void) { _delay_us(SERIAL_DELAY); } inline static void serial_delay_half1(void) ALWAYS_INLINE; inline static void serial_delay_half1(void) { _delay_us(SERIAL_DELAY_HALF1); } inline static void serial_delay_half2(void) ALWAYS_INLINE; inline static void serial_delay_half2(void) { _delay_us(SERIAL_DELAY_HALF2); } inline static void serial_output(void) ALWAYS_INLINE; inline static void serial_output(void) { SERIAL_PIN_DDR |= SERIAL_PIN_MASK; } // make the serial pin an input with pull-up resistor inline static void serial_input_with_pullup(void) ALWAYS_INLINE; inline static void serial_input_with_pullup(void) { SERIAL_PIN_DDR &= ~SERIAL_PIN_MASK; SERIAL_PIN_PORT |= SERIAL_PIN_MASK; } inline static uint8_t serial_read_pin(void) ALWAYS_INLINE; inline static uint8_t serial_read_pin(void) { return !!(SERIAL_PIN_INPUT & SERIAL_PIN_MASK); } inline static void serial_low(void) ALWAYS_INLINE; inline static void serial_low(void) { SERIAL_PIN_PORT &= ~SERIAL_PIN_MASK; } inline static void serial_high(void) ALWAYS_INLINE; inline static void serial_high(void) { SERIAL_PIN_PORT |= SERIAL_PIN_MASK; } void soft_serial_initiator_init(SSTD_t *sstd_table, int sstd_table_size) { Transaction_table = sstd_table; Transaction_table_size = (uint8_t)sstd_table_size; serial_output(); serial_high(); } void soft_serial_target_init(SSTD_t *sstd_table, int sstd_table_size) { Transaction_table = sstd_table; Transaction_table_size = (uint8_t)sstd_table_size; serial_input_with_pullup(); // Enable INT0-INT3,INT6 EIMSK |= EIMSK_BIT; #if SERIAL_PIN_MASK == _BV(PE6) // Trigger on falling edge of INT6 EICRB &= EICRx_BIT; #else // Trigger on falling edge of INT0-INT3 EICRA &= EICRx_BIT; #endif } // Used by the sender to synchronize timing with the reciver. static void sync_recv(void) NO_INLINE; static void sync_recv(void) { for (uint8_t i = 0; i < SERIAL_DELAY*5 && serial_read_pin(); i++ ) { } // This shouldn't hang if the target disconnects because the // serial line will float to high if the target does disconnect. while (!serial_read_pin()); } // Used by the reciver to send a synchronization signal to the sender. static void sync_send(void) NO_INLINE; static void sync_send(void) { serial_low(); serial_delay(); serial_high(); } // Reads a byte from the serial line static uint8_t serial_read_chunk(uint8_t *pterrcount, uint8_t bit) NO_INLINE; static uint8_t serial_read_chunk(uint8_t *pterrcount, uint8_t bit) { uint8_t byte, i, p, pb; _delay_sub_us(READ_WRITE_START_ADJUST); for( i = 0, byte = 0, p = PARITY; i < bit; i++ ) { serial_delay_half1(); // read the middle of pulses if( serial_read_pin() ) { byte = (byte << 1) | 1; p ^= 1; } else { byte = (byte << 1) | 0; p ^= 0; } _delay_sub_us(READ_WRITE_WIDTH_ADJUST); serial_delay_half2(); } /* recive parity bit */ serial_delay_half1(); // read the middle of pulses pb = serial_read_pin(); _delay_sub_us(READ_WRITE_WIDTH_ADJUST); serial_delay_half2(); *pterrcount += (p != pb)? 1 : 0; return byte; } // Sends a byte with MSB ordering void serial_write_chunk(uint8_t data, uint8_t bit) NO_INLINE; void serial_write_chunk(uint8_t data, uint8_t bit) { uint8_t b, p; for( p = PARITY, b = 1<<(bit-1); b ; b >>= 1) { if(data & b) { serial_high(); p ^= 1; } else { serial_low(); p ^= 0; } serial_delay(); } /* send parity bit */ if(p & 1) { serial_high(); } else { serial_low(); } serial_delay(); serial_low(); // sync_send() / senc_recv() need raise edge } static void serial_send_packet(uint8_t *buffer, uint8_t size) NO_INLINE; static void serial_send_packet(uint8_t *buffer, uint8_t size) { for (uint8_t i = 0; i < size; ++i) { uint8_t data; data = buffer[i]; sync_send(); serial_write_chunk(data,8); } } static uint8_t serial_recive_packet(uint8_t *buffer, uint8_t size) NO_INLINE; static uint8_t serial_recive_packet(uint8_t *buffer, uint8_t size) { uint8_t pecount = 0; for (uint8_t i = 0; i < size; ++i) { uint8_t data; sync_recv(); data = serial_read_chunk(&pecount, 8); buffer[i] = data; } return pecount == 0; } inline static void change_sender2reciver(void) { sync_send(); //0 serial_delay_half1(); //1 serial_low(); //2 serial_input_with_pullup(); //2 serial_delay_half1(); //3 } inline static void change_reciver2sender(void) { sync_recv(); //0 serial_delay(); //1 serial_low(); //3 serial_output(); //3 serial_delay_half1(); //4 } static inline uint8_t nibble_bits_count(uint8_t bits) { bits = (bits & 0x5) + (bits >> 1 & 0x5); bits = (bits & 0x3) + (bits >> 2 & 0x3); return bits; } // interrupt handle to be used by the target device ISR(SERIAL_PIN_INTERRUPT) { #ifndef SERIAL_USE_MULTI_TRANSACTION serial_low(); serial_output(); SSTD_t *trans = Transaction_table; #else // recive transaction table index uint8_t tid, bits; uint8_t pecount = 0; sync_recv(); bits = serial_read_chunk(&pecount,7); tid = bits>>3; bits = (bits&7) != nibble_bits_count(tid); if( bits || pecount> 0 || tid > Transaction_table_size ) { return; } serial_delay_half1(); serial_high(); // response step1 low->high serial_output(); _delay_sub_us(SLAVE_INT_ACK_WIDTH_UNIT*SLAVE_INT_ACK_WIDTH); SSTD_t *trans = &Transaction_table[tid]; serial_low(); // response step2 ack high->low #endif // target send phase if( trans->target2initiator_buffer_size > 0 ) serial_send_packet((uint8_t *)trans->target2initiator_buffer, trans->target2initiator_buffer_size); // target switch to input change_sender2reciver(); // target recive phase if( trans->initiator2target_buffer_size > 0 ) { if (serial_recive_packet((uint8_t *)trans->initiator2target_buffer, trans->initiator2target_buffer_size) ) { *trans->status = TRANSACTION_ACCEPTED; } else { *trans->status = TRANSACTION_DATA_ERROR; } } else { *trans->status = TRANSACTION_ACCEPTED; } sync_recv(); //weit initiator output to high } ///////// // start transaction by initiator // // int soft_serial_transaction(int sstd_index) // // Returns: // TRANSACTION_END // TRANSACTION_NO_RESPONSE // TRANSACTION_DATA_ERROR // this code is very time dependent, so we need to disable interrupts #ifndef SERIAL_USE_MULTI_TRANSACTION int soft_serial_transaction(void) { SSTD_t *trans = Transaction_table; #else int soft_serial_transaction(int sstd_index) { if( sstd_index > Transaction_table_size ) return TRANSACTION_TYPE_ERROR; SSTD_t *trans = &Transaction_table[sstd_index]; #endif cli(); // signal to the target that we want to start a transaction serial_output(); serial_low(); _delay_us(SLAVE_INT_WIDTH_US); #ifndef SERIAL_USE_MULTI_TRANSACTION // wait for the target response serial_input_with_pullup(); _delay_us(SLAVE_INT_RESPONSE_TIME); // check if the target is present if (serial_read_pin()) { // target failed to pull the line low, assume not present serial_output(); serial_high(); *trans->status = TRANSACTION_NO_RESPONSE; sei(); return TRANSACTION_NO_RESPONSE; } #else // send transaction table index int tid = (sstd_index<<3) | (7 & nibble_bits_count(sstd_index)); sync_send(); _delay_sub_us(TID_SEND_ADJUST); serial_write_chunk(tid, 7); serial_delay_half1(); // wait for the target response (step1 low->high) serial_input_with_pullup(); while( !serial_read_pin() ) { _delay_sub_us(2); } // check if the target is present (step2 high->low) for( int i = 0; serial_read_pin(); i++ ) { if (i > SLAVE_INT_ACK_WIDTH + 1) { // slave failed to pull the line low, assume not present serial_output(); serial_high(); *trans->status = TRANSACTION_NO_RESPONSE; sei(); return TRANSACTION_NO_RESPONSE; } _delay_sub_us(SLAVE_INT_ACK_WIDTH_UNIT); } #endif // initiator recive phase // if the target is present syncronize with it if( trans->target2initiator_buffer_size > 0 ) { if (!serial_recive_packet((uint8_t *)trans->target2initiator_buffer, trans->target2initiator_buffer_size) ) { serial_output(); serial_high(); *trans->status = TRANSACTION_DATA_ERROR; sei(); return TRANSACTION_DATA_ERROR; } } // initiator switch to output change_reciver2sender(); // initiator send phase if( trans->initiator2target_buffer_size > 0 ) { serial_send_packet((uint8_t *)trans->initiator2target_buffer, trans->initiator2target_buffer_size); } // always, release the line when not in use sync_send(); *trans->status = TRANSACTION_END; sei(); return TRANSACTION_END; } #ifdef SERIAL_USE_MULTI_TRANSACTION int soft_serial_get_and_clean_status(int sstd_index) { SSTD_t *trans = &Transaction_table[sstd_index]; cli(); int retval = *trans->status; *trans->status = 0;; sei(); return retval; } #endif #endif // Helix serial.c history // 2018-1-29 fork from let's split and add PD2, modify sync_recv() (#2308, bceffdefc) // 2018-6-28 bug fix master to slave comm and speed up (#3255, 1038bbef4) // (adjusted with avr-gcc 4.9.2) // 2018-7-13 remove USE_SERIAL_PD2 macro (#3374, f30d6dd78) // (adjusted with avr-gcc 4.9.2) // 2018-8-11 add support multi-type transaction (#3608, feb5e4aae) // (adjusted with avr-gcc 4.9.2) // 2018-10-21 fix serial and RGB animation conflict (#4191, 4665e4fff) // (adjusted with avr-gcc 7.3.0) // 2018-10-28 re-adjust compiler depend value of delay (#4269, 8517f8a66) // (adjusted with avr-gcc 5.4.0, 7.3.0)