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29 * Copyright 2007 Develer S.r.l. (http://www.develer.com/)
33 * \brief PCF8574 i2c port expander driver.
35 * This driver controls the PCF8574.
36 * The PCF8574 is an 8bit i2c port expander.
37 * You can read/write 8 pins through an i2c bus.
38 * The pins are quasi-bidirectionals, this mean that
39 * without the need of a direction register you can use
40 * each pin as input or output, see datasheet on how this
43 * \author Francesco Sacchi <batt@develer.com>
48 #include <cfg/module.h>
53 * Read PCF8574 \a pcf bit status.
54 * \return the pins status or EOF on errors.
56 int pcf8574_get_1(Pcf8574 *pcf)
58 if (!i2c_start_r(PCF8574ID | ((pcf->addr << 1) & 0xF7)))
63 if (!i2c_recv(&data, 1))
72 * Write to PCF8574 \a pcf port \a data.
73 * \return true if ok, false on errors.
75 bool pcf8574_put_2(Pcf8574 *pcf, uint8_t data)
77 bool res = i2c_start_w(PCF8574ID | ((pcf->addr << 1) & 0xF7)) && i2c_put(data);
83 * Init a PCF8574 on the bus with addr \a addr.
84 * \return true if device is found, false otherwise.
86 bool pcf8574_init_2(Pcf8574 *pcf, pcf8574_addr addr)
90 return pcf8574_get(pcf) != EOF;
100 * Read PCF8574 \a pcf bit status.
101 * \return the pins status or EOF on errors.
103 int pcf8574_get_2(I2c *i2c, Pcf8574 *pcf)
105 i2c_start_r(i2c, PCF8574ID | ((pcf->addr << 1) & 0xF7), 1, I2C_STOP);
107 int data = i2c_getc(i2c);
116 * Write to PCF8574 \a pcf port \a data.
117 * \return true if ok, false on errors.
119 bool pcf8574_put_3(I2c *i2c, Pcf8574 *pcf, uint8_t data)
121 i2c_start_w(i2c, PCF8574ID | ((pcf->addr << 1) & 0xF7), 1, I2C_STOP);
131 * Init a PCF8574 on the bus with addr \a addr.
132 * \return true if device is found, false otherwise.
134 bool pcf8574_init_3(I2c *i2c, Pcf8574 *pcf, pcf8574_addr addr)
139 return (pcf8574_get(i2c, pcf) != EOF);