/* AT TINY 85 +--\/--+ RESET _| 1 8 |_ +5V ~OC1B HOLD DDB3 _| 2 7 |_ SCL OC1B ONSET DDB4 _| 3 6 |_ DDB1 LED GND _| 4 5 |_ SDA +------+ * = Serial and/or programming pins on Arduino as ISP */ // This program acts as the device (slave) for the control program i2c/a2a/c_ctl #define F_CPU 8000000L #include #include #include #include #include "usiTwiSlave.h" enum { kTmr0_Prescale_idx = 0, // Timer 0 clock divider: 1=1,2=8,3=64,4=256,5=1024 kTmr0_Coarse_idx = 1, // kTmr0_Fine_idx = 2, // kPWM1_Duty_idx = 3, // kPWM1_Freq_idx = 4, // kTable_Addr_idx = 5, // Next table address to read/write kTable_Coarse_idx = 6, // Next table coarse value to read/write kTable_Fine_idx = 7, // Next table fine value to read/write kMax_idx }; volatile uint8_t ctl_regs[] = { 4, // 0 (1-5) 4=32us per tick 123, // 1 (0-255) Timer 0 Coarse Value 8, // 2 (0-255) Timer 0 Fine Value 127, // 3 (0-255) PWM1 Duty cycle 254, // 4 (0-255) PWM1 Frequency (123 hz) 0, // 5 (0-127) Next table addr to read/write 0, // 6 (0-255) Next table coarse value to write 0, // 7 (0-255) Next table fine value to write }; #define tableN 256 uint8_t table[ tableN ]; //------------------------------------------------------------------------------ //------------------------------------------------------------------------------ //------------------------------------------------------------------------------ // // EEPROM // void EEPROM_write(uint8_t ucAddress, uint8_t ucData) { // Wait for completion of previous write while(EECR & (1< 127 // r 8 kTable_Fine_idx -> 64 #define eeprom_addr( addr ) (kMax_idx + (addr)) void table_write_cur_value( void ) { uint8_t tbl_addr = ctl_regs[ kTable_Addr_idx ] * 2; table[ tbl_addr+0 ] = ctl_regs[ kTable_Coarse_idx ]; table[ tbl_addr+1 ] = ctl_regs[ kTable_Fine_idx ]; EEPROM_write( eeprom_addr( tbl_addr+0 ), ctl_regs[ kTable_Coarse_idx ] ); EEPROM_write( eeprom_addr( tbl_addr+1 ), ctl_regs[ kTable_Fine_idx ]); } void table_load( void ) { uint8_t i = 0; for(; i<128; ++i) { uint8_t tbl_addr = i*2; table[tbl_addr+0] = EEPROM_read( eeprom_addr(tbl_addr+0) ); table[tbl_addr+1] = EEPROM_read( eeprom_addr(tbl_addr+1) ); } } void restore_memory_from_eeprom( void ) { /* uint8_t i; for(i=0; i 0 ) { tmr0_state = 1; OCR0A = 0xff; } else // otherwise go into fine mode { tmr0_state = 2; OCR0A = ctl_regs[kTmr0_Fine_idx]; } tmr0_coarse_cur = 0; } ISR(TIMER0_COMPA_vect) { switch( tmr0_state ) { case 0: // disabled break; case 1: // coarse mode if( ++tmr0_coarse_cur >= ctl_regs[kTmr0_Coarse_idx] ) { tmr0_state = 2; OCR0A = ctl_regs[kTmr0_Fine_idx]; } break; case 2: // fine mode PINB = _BV(PINB4); // writes to PINB toggle the pins tmr0_reset(); // restart the timer break; } } void timer0_init() { TIMSK &= ~_BV(OCIE0A); // Disable interrupt TIMER1_OVF TCCR0A |= 0x02; // CTC mode TCCR0B |= ctl_regs[kTmr0_Prescale_idx]; // set the prescaler GTCCR |= _BV(PSR0); // Set the pre-scaler to the selected value tmr0_reset(); // set the timers starting state TIMSK |= _BV(OCIE0A); // Enable interrupt TIMER1_OVF } //------------------------------------------------------------------------------ //------------------------------------------------------------------------------ //------------------------------------------------------------------------------ // // PWM1 // // PWM is optimized to use pins OC1A ,~OC1A, OC1B, ~OC1B but this code // but since these pins are not available this code uses // ISR's to redirect the output to PIN3 void pwm1_update() { OCR1B = ctl_regs[kPWM1_Duty_idx]; // control duty cycle OCR1C = ctl_regs[kPWM1_Freq_idx]; // PWM frequency pre-scaler } ISR(TIMER1_OVF_vect) { PORTB |= _BV(PINB3); // set PWM pin } ISR(TIMER1_COMPB_vect) { PORTB &= ~(_BV(PINB3)); // clear PWM pin } void pwm1_init() { TIMSK &= ~(_BV(OCIE1B) + _BV(TOIE1)); // Disable interrupts DDRB |= _BV(DDB3); // setup PB3 as output // set on TCNT1 == 0 // happens when TCNT1 matches OCR1C // clr on OCR1B == TCNT // happens when TCNT1 matches OCR1B // // COM1B1=1 COM1B0=0 (enable output on ~OC1B) TCCR1 |= 9; // 32us period (256 divider) prescaler GTCCR |= _BV(PWM1B); // Enable PWM B and disconnect output pins GTCCR |= _BV(PSR1); // Set the pre-scaler to the selected value pwm1_update(); TIMSK |= _BV(OCIE1B) + _BV(TOIE1); // Enable interrupts } //------------------------------------------------------------------------------ //------------------------------------------------------------------------------ //------------------------------------------------------------------------------ // Tracks the current register pointer position volatile uint8_t reg_position = 0; const uint8_t reg_size = sizeof(ctl_regs); // // Read Request Handler // // This is called for each read request we receive, never put more // than one byte of data (with TinyWireS.send) to the send-buffer when // using this callback // void on_request() { uint8_t val = 0; switch( reg_position ) { case kTable_Coarse_idx: val = table[ ctl_regs[kTable_Addr_idx]*2 + 0 ]; break; case kTable_Fine_idx: val = table[ ctl_regs[kTable_Addr_idx]*2 + 1 ]; break; default: // read and transmit the requestd position val = ctl_regs[reg_position]; } usiTwiTransmitByte(val); // Increment the reg position on each read, and loop back to zero reg_position++; if (reg_position >= reg_size) { reg_position = 0; } } // // The I2C data received -handler // // This needs to complete before the next incoming transaction (start, // data, restart/stop) on the bus does so be quick, set flags for long // running tasks to be called from the mainloop instead of running // them directly, // void on_receive( uint8_t byteN ) { PINB = _BV(PINB1); // writes to PINB toggle the pins if (byteN < 1) { // Sanity-check return; } if (byteN > TWI_RX_BUFFER_SIZE) { // Also insane number return; } // get the register index to read/write reg_position = usiTwiReceiveByte(); byteN--; // If only one byte was received then this was a read request // and the buffer pointer (reg_position) is now set to return the byte // at this location on the subsequent call to on_request() ... if (!byteN) { return; } // ... otherwise this was a write request and the buffer // pointer is now pointing to the first byte to write to while(byteN--) { // write the value ctl_regs[reg_position] = usiTwiReceiveByte(); // Set timer 1 if( kTmr0_Prescale_idx <= reg_position && reg_position <= kTmr0_Fine_idx ) { timer0_init(); } else // Set PWM 1 if( kPWM1_Duty_idx <= reg_position && reg_position <= kPWM1_Freq_idx ) { pwm1_update(); } else // Write table if( reg_position == kTable_Fine_idx ) { table_write_cur_value(); } reg_position++; if (reg_position >= reg_size) { reg_position = 0; } } } int main(void) { cli(); // mask all interupts restore_memory_from_eeprom(); DDRB |= _BV(DDB4) + _BV(DDB3) + _BV(DDB1); // setup PB4,PB3,PB1 as output PORTB &= ~(_BV(PINB4) + _BV(PINB3) + _BV(PINB1)); // clear output pins timer0_init(); pwm1_init(); // setup i2c library usi_onReceiverPtr = on_receive; usi_onRequestPtr = on_request; usiTwiSlaveInit(I2C_SLAVE_ADDRESS); sei(); PINB = _BV(PINB1); // writes to PINB toggle the pins _delay_ms(1000); PINB = _BV(PINB1); // writes to PINB toggle the pins while(1) { //_delay_ms(1000); if (!usi_onReceiverPtr) { // no onReceive callback, nothing to do... continue; } if (!(USISR & ( 1 << USIPF ))) { // Stop not detected continue; } uint8_t amount = usiTwiAmountDataInReceiveBuffer(); if (amount == 0) { // no data in buffer continue; } usi_onReceiverPtr(amount); } return 0; }