GY-63_MS5611/libraries/PCF8574/PCF8574.cpp
2024-01-08 15:12:06 +01:00

225 lines
4.0 KiB
C++

//
// FILE: PCF8574.cpp
// AUTHOR: Rob Tillaart
// DATE: 02-febr-2013
// VERSION: 0.4.1
// PURPOSE: Arduino library for PCF8574 - 8 channel I2C IO expander
// URL: https://github.com/RobTillaart/PCF8574
// http://forum.arduino.cc/index.php?topic=184800
#include "PCF8574.h"
PCF8574::PCF8574(const uint8_t deviceAddress, TwoWire *wire)
{
_address = deviceAddress;
_wire = wire;
_dataIn = 0;
_dataOut = 0xFF;
_buttonMask = 0xFF;
_error = PCF8574_OK;
}
bool PCF8574::begin(uint8_t value)
{
if (! isConnected()) return false;
PCF8574::write8(value);
return true;
}
bool PCF8574::isConnected()
{
_wire->beginTransmission(_address);
return ( _wire->endTransmission() == 0);
}
bool PCF8574::setAddress(const uint8_t deviceAddress)
{
_address = deviceAddress;
return isConnected();
}
uint8_t PCF8574::getAddress()
{
return _address;
}
// removed _wire->beginTransmission(_address);
// with @100 KHz -> 265 micros()
// without @100 KHz -> 132 micros()
// without @400 KHz -> 52 micros()
// TODO @800 KHz -> ??
uint8_t PCF8574::read8()
{
if (_wire->requestFrom(_address, (uint8_t)1) != 1)
{
_error = PCF8574_I2C_ERROR;
return _dataIn; // last value
}
_dataIn = _wire->read();
return _dataIn;
}
void PCF8574::write8(const uint8_t value)
{
_dataOut = value;
_wire->beginTransmission(_address);
_wire->write(_dataOut);
_error = _wire->endTransmission();
}
uint8_t PCF8574::read(const uint8_t pin)
{
if (pin > 7)
{
_error = PCF8574_PIN_ERROR;
return 0;
}
PCF8574::read8();
return (_dataIn & (1 << pin)) > 0;
}
void PCF8574::write(const uint8_t pin, const uint8_t value)
{
if (pin > 7)
{
_error = PCF8574_PIN_ERROR;
return;
}
if (value == LOW)
{
_dataOut &= ~(1 << pin);
}
else
{
_dataOut |= (1 << pin);
}
write8(_dataOut);
}
void PCF8574::toggle(const uint8_t pin)
{
if (pin > 7)
{
_error = PCF8574_PIN_ERROR;
return;
}
toggleMask(1 << pin);
}
void PCF8574::toggleMask(const uint8_t mask)
{
_dataOut ^= mask;
PCF8574::write8(_dataOut);
}
void PCF8574::shiftRight(const uint8_t n)
{
if ((n == 0) || (_dataOut == 0)) return;
if (n > 7) _dataOut = 0; // shift 8++ clears all, valid...
if (_dataOut != 0) _dataOut >>= n; // only shift if there are bits set
PCF8574::write8(_dataOut);
}
void PCF8574::shiftLeft(const uint8_t n)
{
if ((n == 0) || (_dataOut == 0)) return;
if (n > 7) _dataOut = 0; // shift 8++ clears all, valid...
if (_dataOut != 0) _dataOut <<= n; // only shift if there are bits set
PCF8574::write8(_dataOut);
}
int PCF8574::lastError()
{
int e = _error;
_error = PCF8574_OK; // reset error after read, is this wise?
return e;
}
void PCF8574::rotateRight(const uint8_t n)
{
uint8_t r = n & 7;
if (r == 0) return;
_dataOut = (_dataOut >> r) | (_dataOut << (8 - r));
PCF8574::write8(_dataOut);
}
void PCF8574::rotateLeft(const uint8_t n)
{
rotateRight(8 - (n & 7));
}
void PCF8574::reverse() // quite fast: 4 and, 14 shifts, 3 or, 3 assignment.
{
uint8_t x = _dataOut;
x = (((x & 0xAA) >> 1) | ((x & 0x55) << 1));
x = (((x & 0xCC) >> 2) | ((x & 0x33) << 2));
x = ((x >> 4) | (x << 4));
PCF8574::write8(x);
}
// added 0.1.07/08 Septillion
uint8_t PCF8574::readButton8(const uint8_t mask)
{
uint8_t temp = _dataOut;
PCF8574::write8(mask | _dataOut); // read only selected lines
PCF8574::read8();
PCF8574::write8(temp); // restore
return _dataIn;
}
// added 0.1.07 Septillion
uint8_t PCF8574::readButton(const uint8_t pin)
{
if (pin > 7)
{
_error = PCF8574_PIN_ERROR;
return 0;
}
uint8_t temp = _dataOut;
PCF8574::write(pin, HIGH);
uint8_t value = PCF8574::read(pin);
PCF8574::write8(temp);
return value;
}
void PCF8574::select(const uint8_t pin)
{
uint8_t n = 0x00;
if (pin < 8) n = 1 << pin;
write8(n);
};
void PCF8574::selectN(const uint8_t pin)
{
uint8_t n = 0xFF;
if (pin < 8) n = (2 << pin) - 1;
write8(n);
};
// -- END OF FILE --