History

Our Air Quality c8c7f97290 i2c: increase the default clock strech timeout to 250msec. This also redefines the timeout in FreeRTOS clock ticks, and implements a two stage wait: firstly spinning sampling frequently, and then falling back to a longer wait while sampling less frequently and yielding.		2018-06-15 08:28:47 +10:00
..
component.mk	Rework component makefiles to have a default <component>_ROOT	2015-09-08 09:59:59 +10:00
i2c.c	i2c: increase the default clock strech timeout to 250msec.	2018-06-15 08:28:47 +10:00
i2c.h	i2c: increase the default clock strech timeout to 250msec.	2018-06-15 08:28:47 +10:00
LICENSE	Added BMP180 and I2C driver and example	2015-08-31 13:39:27 +02:00
README.md	I2C code formatting, README fix (#462 )	2017-10-12 17:42:34 +05:00

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].

Basic usage

#include <i2c.h>

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

uint8_t slave_addr = 0x20;
uint8_t reg_addr = 0x1f;
uint8_t reg_data;

i2c_init(BUS, SCL_PIN, SDA_PIN, I2C_FREQ_400K);

// Write 1 byte to slave register
int err = i2c_slave_write(BUS, slave_addr, &reg_addr, &data, 1);
if (err != 0)
{
	// do something with error
}

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

For details please see extras/i2c/i2c.h.

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