I2C BB

I2C bitbang gpio driver using gpio_sys gpio driver

Installation

make install

Installs libi2c_bb.a and libi2c_bb.so in the directory $(PREFIX)/lib/. It also installs the include header file i2c.h in the directory $(PREFIX)/include/i2c_bb/. The default value for PREFIX is: PREFIX=usr. To use another location for installation changing the value of the PREFIX variable is needed. E.g.:

PREFIX=/usr/local/ make install

Uninstallation

make install

Removes the files installed with the install make target.

NOTE: If PREFIX variable was changed during installation process the same value needs to be set for uninstallation. E.g.:

PREFIX=/usr/local/ make install

Example

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <syslog.h>
#include <stdbool.h>

#include <i2c_bb/i2c.h>

#define I2C_SLAVE_ADDR  0x48
#define BUFFER_SIZE     3

static const struct gpio_sys gpio_sda = {
    .pin = 4,
    .direction = 0, // out
};

static const struct gpio_sys gpio_scl = {
    .pin = 24,
    .direction = 0, // out
};

const static struct i2c_bb i2c_dev = {
    .sda = &gpio_sda,
    .scl = &gpio_scl,
};

int main(void)
{
    int res;
    char buffer[BUFFER_SIZE]

    openlog("i2c_bb", LOG_CONS | LOG_PID | LOG_NDELAY, LOG_LOCAL1);

    res = i2c_open(&i2c_dev);
    if(res != EXIT_SUCCESS) {
        syslog(LOG_ERR, "Unable to open i2c device.\n");
        return res;
    }

    buffer[0] = 0x01;
    buffer[1] = 0xc1;
    buffer[2] = 0x87;

    // Write to register address 0x01 value 0xc187:
    i2c_write(&i2c_dev, I2C_SLAVE_ADDR, buffer, BUFFER_SIZE);

    buffer[0] = 0x00;

    // Set register address 0x00:
    i2c_write(&i2c_dev, addr, buffer, 1);

    // Read from register 0x00 two bytes:
    i2c_read(&i2c_dev, I2C_SLAVE_ADDR, buffer, 2);

    i2c_close(&i2c_dev);

    return EXIT_SUCCESS;
}

Additional make targets

Target	Meaning
all	Build the code, assemble the static and shared library.
install	Install the libraries and necessary include header files.
uninstall	Uninstall the libraries and necessary include header files.
clean	Clean up build artifacts.
distclean	Remove all folders created during any build step.
build_unit_test	Build the unit tests.
exec_unit_test	Execute the unit tests.
coverage	Determine code coverage of the unit tests.
check	Static code analysis (cppcheck).