History

ourairquality 16157080cd i2c: use open drain outputs. Configure the pins as open-drain just in case the code forces them high although it should be configuring them as inputs to let them float high. Initialize the pins when the driver is initialized. Enable the internal pull-ups to prevent them floating too high if not connected and damaging the circuit.		2016-07-18 14:35:01 +10:00
..
component.mk	Rework component makefiles to have a default <component>_ROOT	2015-09-08 09:59:59 +10:00
i2c.c	i2c: use open drain outputs.	2016-07-18 14:35:01 +10:00
i2c.h	Added BMP180 and I2C driver and example	2015-08-31 13:39:27 +02:00
LICENSE	Added BMP180 and I2C driver and example	2015-08-31 13:39:27 +02:00
README.md	Added BMP180 and I2C driver and example	2015-08-31 13:39:27 +02:00

README.md

Yet another I2C driver for the ESP8266

This time a driver for the excellent esp-open-rtos. This is a bit banging I2C driver based on the Wikipedia pesudo C code [1].

Adding to your project

Add the driver to your project as a submodule rather than cloning it:

% git submodule add https://github.com/kanflo/esp-open-rtos-driver-i2c.git i2c

The esp-open-rtos makefile-fu will make sure the driver is built.

Usage

#include <i2c.h>

#define SCL_PIN (0)
#define SDA_PIN (2)

uint8_t slave_addr = 0x20;
uint8_t reg_addr = 0x1f;
uint8_t reg_data;
uint8_t data[] = {reg_addr, 0xc8};

i2c_init(SCL_PIN, SDA_PIN);

// Write data to slave
bool success = i2c_slave_write(slave_addr, data, sizeof(data));

// Issue write to slave, sending reg_addr, followed by reading 1 byte
success = i2c_slave_read(slave_addr, &reg_addr, reg_data, 1);

The driver is released under the MIT license.

[1] https://en.wikipedia.org/wiki/I²C#Example_of_bit-banging_the_I.C2.B2C_Master_protocol