File syn_soft_i2c.h¶

FileList > drivers > syn_soft_i2c.h

Software I2C (bit-banging) driver. More...

#include "../common/syn_defs.h"
#include <stdbool.h>
#include <stdint.h>

Classes¶

Type	Name
struct	SYN_SoftI2C Software I2C instance.

Public Functions¶

Type	Name
void	syn_soft_i2c_init (SYN_SoftI2C * i2c, SYN_GPIO_Pin scl, SYN_GPIO_Pin sda, uint32_t delay_loops) Initialize the soft I2C pins.
uint8_t	syn_soft_i2c_read (const SYN_SoftI2C * i2c, bool ack) Read a byte from the I2C bus.
void	syn_soft_i2c_start (const SYN_SoftI2C * i2c) Generate an I2C START condition.
void	syn_soft_i2c_stop (const SYN_SoftI2C * i2c) Generate an I2C STOP condition.
bool	syn_soft_i2c_write (const SYN_SoftI2C * i2c, uint8_t data) Write a byte to the I2C bus.
bool	syn_soft_i2c_write_read (SYN_SoftI2C * i2c, uint8_t dev_addr, const uint8_t * tx_data, size_t tx_len, uint8_t * rx_data, size_t rx_len) Perform a write-then-read I2C transaction.

Detailed Description¶

Implements I2C master functionality using any two GPIO pins. Relies on syn_port_gpio.h for pin manipulation. Uses a simple NOP loop for clock stretching/delays.

Public Functions Documentation¶

function syn_soft_i2c_init¶

Initialize the soft I2C pins.

void syn_soft_i2c_init (
    SYN_SoftI2C * i2c,
    SYN_GPIO_Pin scl,
    SYN_GPIO_Pin sda,
    uint32_t delay_loops
)

Parameters:

i2c Pointer to I2C instance.
scl SCL pin.
sda SDA pin.
delay_loops Number of iterations for a half-clock delay.

function syn_soft_i2c_read¶

Read a byte from the I2C bus.

uint8_t syn_soft_i2c_read (
    const SYN_SoftI2C * i2c,
    bool ack
)

Parameters:

i2c Pointer to I2C instance.
ack true to ACK the byte, false to NACK (end of read).

Returns:

The byte read.

function syn_soft_i2c_start¶

Generate an I2C START condition.

void syn_soft_i2c_start (
    const SYN_SoftI2C * i2c
)

Parameters:

i2c Pointer to I2C instance.

function syn_soft_i2c_stop¶

Generate an I2C STOP condition.

void syn_soft_i2c_stop (
    const SYN_SoftI2C * i2c
)

Parameters:

i2c Pointer to I2C instance.

function syn_soft_i2c_write¶

Write a byte to the I2C bus.

bool syn_soft_i2c_write (
    const SYN_SoftI2C * i2c,
    uint8_t data
)

Parameters:

i2c Pointer to I2C instance.
data Byte to write.

Returns:

true if the slave ACKed, false if NACKed.

function syn_soft_i2c_write_read¶

Perform a write-then-read I2C transaction.

bool syn_soft_i2c_write_read (
    SYN_SoftI2C * i2c,
    uint8_t dev_addr,
    const uint8_t * tx_data,
    size_t tx_len,
    uint8_t * rx_data,
    size_t rx_len
)

Sends a START, writes the device address + tx_data, then issues a repeated START, reads rx_len bytes into rx_data, and sends a STOP. This covers the common "write register address, read data" pattern.

Parameters:

i2c I2C instance.
dev_addr 7-bit device address (will be left-shifted internally).
tx_data Data to write (e.g., register address). Can be NULL if tx_len is 0.
tx_len Number of bytes to write.
rx_data Buffer to read into. Can be NULL if rx_len is 0.
rx_len Number of bytes to read.

Returns:

true if all bytes were ACKed, false on NACK.

The documentation for this class was generated from the following file src/syntropic/drivers/syn_soft_i2c.h