uint8_t USI_TWI::requestFrom(uint8_t slaveAddr, uint8_t numBytes){ // setup for receiving from slave
bool xferOK = false;
uint8_t errorCode = 0;
USI_LastRead = 0;
USI_BytesAvail = numBytes; // save this off in a global
numBytes++; // add extra byte to transmit header
USI_Buf[0] = (slaveAddr<<TWI_ADR_BITS) | USI_RCVE; // setup address & Rcve bit
xferOK = USI_TWI_Start_Read_Write(USI_Buf,numBytes); // core func that does the work
// USI_Buf now holds the data read
if (xferOK) return 0;
else { // there was an error
errorCode = USI_TWI_Get_State_Info(); // this function returns the error number
return errorCode;
}
}
uint8_t USI_TWI::read(){ // returns the bytes received one at a time
USI_LastRead++; // inc first since first uint8_t read is in USI_Buf[1]
return USI_Buf[USI_LastRead];
}
uint8_t USI_TWI::available(){ // the bytes available that haven't been read yet
return USI_BytesAvail - (USI_LastRead);
}
// Preinstantiate Objects //////////////////////////////////////////////////////
USI_TWI TinyWireM = USI_TWI();
USI_Buf[0] = (slaveAddr<<TWI_ADR_BITS) | USI_RCVE; // setup address & Rcve bit
xferOK = USI_TWI_Start_Read_Write(USI_Buf,numBytes); // core func that does the work
// USI_Buf now holds the data read
if (xferOK) {
errorCode = USI_TWI_Master_Stop();
if (errorCode == 0) {
errorCode = USI_TWI_Get_State_Info();
return errorCode;
}
return 0;
}
else { // there was an error
errorCode = USI_TWI_Get_State_Info(); // this function returns the error number
return errorCode;
}
}
uint8_t USI_TWI::read(){ // returns the bytes received one at a time
USI_LastRead++; // inc first since first uint8_t read is in USI_Buf[1]
return USI_Buf[USI_LastRead];
}
int USI_TWI::available(){ // the bytes available that haven't been read yet
return USI_BytesAvail - (USI_LastRead);
}
// Preinstantiate Objects //////////////////////////////////////////////////////
USI_TWI Wire = USI_TWI();
