124 lines
3.4 KiB
C++
124 lines
3.4 KiB
C++
/*!
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* @file Adafruit_PCF8575.cpp
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*
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* @mainpage Adafruit PCF8575 I2C Potentiometer
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*
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* @section intro_sec Introduction
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*
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* I2C Driver for the NXP PCF8575 I2C GPIO expander
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*
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* This is a library for the Adafruit PCF8575 breakout:
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* http://www.adafruit.com/products
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*
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* Adafruit invests time and resources providing this open source code,
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* please support Adafruit and open-source hardware by purchasing products from
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* Adafruit!
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*
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* @section dependencies Dependencies
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*
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* This library depends on the Adafruit BusIO library
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*
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* @section author Author
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*
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* ladyada for Adafruit Industries
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*
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* @section license License
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*
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* BSD (see license.txt)
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*
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* @section HISTORY
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*
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* v1.0 - First release
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*/
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#include "Adafruit_PCF8575.h"
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/*!
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* @brief Instantiates a new PCF8575 class
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*/
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Adafruit_PCF8575::Adafruit_PCF8575(void) {}
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/*!
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* @brief Sets up the hardware and initializes I2C
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* @param i2c_address
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* The I2C address to be used.
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* @param wire
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* The Wire object to be used for I2C connections.
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* @return True if initialization was successful, otherwise false.
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*/
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bool Adafruit_PCF8575::begin(uint8_t i2c_address, TwoWire *wire) {
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delete (i2c_dev);
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i2c_dev = new Adafruit_I2CDevice(i2c_address, wire);
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if (!i2c_dev->begin()) {
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return false;
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}
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return true;
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}
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/*!
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* @brief Write one 'word' of data directly to the GPIO control register
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* @param d The data to write
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* @return True if we were able to write the data successfully over I2C
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*/
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bool Adafruit_PCF8575::digitalWriteWord(uint16_t d) {
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_writebuf = d;
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return i2c_dev->write((uint8_t *)&_writebuf, 2);
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}
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/*!
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* @brief Read one 'word' of data directly from the GPIO control register
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* @return The byte of data read from the device
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*/
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uint16_t Adafruit_PCF8575::digitalReadWord(void) {
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i2c_dev->read((uint8_t *)&_readbuf, 2);
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return _readbuf;
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}
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/*!
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* @brief Set one GPIO expander pin to 'high' (weak pullup) or 'low'
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* (grounded)
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* @param pinnum The GPIO pin number, from 0 to 7 inclusive
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* @param val The boolean value to write: true means activate the pullup
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* and false means turn on the sinking transistor.
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* @return True if we were able to write the data successfully over I2C
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*/
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bool Adafruit_PCF8575::digitalWrite(uint8_t pinnum, bool val) {
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if (val) {
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_writebuf |= 1UL << pinnum;
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} else {
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_writebuf &= ~(1UL << pinnum);
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}
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return i2c_dev->write((uint8_t *)&_writebuf, 2);
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}
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/*!
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* @brief Set one GPIO expander pin to 'output' (grounded) or 'input' (weak
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* pullup)
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* @param pinnum The GPIO pin number, from 0 to 15 inclusive
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* @param val The value to write: INPUT or INPUT_PULLUP means activate the
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* pullup and OUTPUT means turn on the sinking transistor, as this is an open
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* drain device
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* @return True if we were able to write the data successfully over I2C
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*/
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bool Adafruit_PCF8575::pinMode(uint8_t pinnum, uint8_t val) {
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if ((val == INPUT) || (val == INPUT_PULLUP)) {
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_writebuf |= 1UL << pinnum;
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} else {
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_writebuf &= ~(1UL << pinnum);
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}
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return i2c_dev->write((uint8_t *)&_writebuf, 2);
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}
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/*!
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* @brief Get a GPIO expander pin value
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* @param pinnum The GPIO pin number, from 0 to 7 inclusive
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* @return True if the pin logic is NOT ground, false if the pin logic is
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* ground
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*/
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bool Adafruit_PCF8575::digitalRead(uint8_t pinnum) {
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i2c_dev->read((uint8_t *)&_readbuf, 2);
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return (_readbuf >> pinnum) & 0x1;
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}
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