void processTWI( void )
{
uint8_t b,p1,p2;
b = usiTwiReceiveByte();
switch (b) {
case 0x81: // set slave address
p1 = usiTwiReceiveByte();
if(p1 < 128) // Address is 7 bit
{
eeprom_update_byte(&b_slave_address, p1);
usiTwiSlaveInit(eeprom_read_byte(&b_slave_address));
}
break;
case 0x82: // clear led
led_clear();
break;
case 0x83: // set led brightness, p1=led, p2=brightness
p1 = usiTwiReceiveByte();
p2 = usiTwiReceiveByte();
set_led_pulse(p1,0); // Turn off pulsing
set_brightness(p1,p2);
break;
case 0x84: // Set to pulse led, p1=led, p2 = (0 = OFF, 1 = ON)
set_led_pulse(usiTwiReceiveByte(),usiTwiReceiveByte());
break;
case 0x85: // Dim up/down led to specific value, p1=led, p2=value to dim to
dim_led(usiTwiReceiveByte(),usiTwiReceiveByte());
break;
case 0x86: // get firmware revision
usiTwiTransmitByte(FIRMWARE_REVISION);
break;
case 0x90: // get keyUp Event
usiTwiTransmitByte(getKeyUp());
break;
case 0x91: // get KeyDown Event
usiTwiTransmitByte(getKeyDown());
break;
case 0x92: // set keyrepeat
set_keyrepeat(usiTwiReceiveByte(),usiTwiReceiveByte());
break;
case 0xFE: // reset to known state
led_clear();
button_init();
flushTwiBuffers();
break;
case 0xFF: // flush the bus
break;
default:
break;
}
}
void
usiTwiSlaveInit(
uint8_t ownAddress
)
{
flushTwiBuffers( );
slaveAddress = ownAddress;
// In Two Wire mode (USIWM1, USIWM0 = 1X), the slave USI will pull SCL
// low when a start condition is detected or a counter overflow (only
// for USIWM1, USIWM0 = 11). This inserts a wait state. SCL is released
// by the ISRs (USI_START_vect and USI_OVERFLOW_vect).
// Set SCL and SDA as output
// DDR_USI |= ( 1 << PORT_USI_SCL ) | ( 1 << PORT_USI_SDA );
// set SCL high
PORT_USI |= ( 1 << PORT_USI_SCL );
// set SDA high
PORT_USI |= ( 1 << PORT_USI_SDA );
// set SCL as output
DDR_USI |= ( 1 << PORT_USI_SCL );
// Set SDA as input
DDR_USI &= ~( 1 << PORT_USI_SDA );
USICR =
// enable Start Condition Interrupt
( 1 << USISIE ) |
// disable Overflow Interrupt
( 0 << USIOIE ) |
// set USI in Two-wire mode, no USI Counter overflow hold
( 1 << USIWM1 ) | ( 0 << USIWM0 ) |
// Shift Register Clock Source = external, positive edge
// 4-Bit Counter Source = external, both edges
( 1 << USICS1 ) | ( 0 << USICS0 ) | ( 0 << USICLK ) |
// no toggle clock-port pin
( 0 << USITC );
// clear all interrupt flags and reset overflow counter
USISR = ( 1 << USI_START_COND_INT ) | ( 1 << USIOIF ) | ( 1 << USIPF ) | ( 1 << USIDC );
} // end usiTwiSlaveInit
