File syn_shiftreg.h¶

FileList > drivers > syn_shiftreg.h

Generic Shift Register Driver (74HC595 Output Expander & 74HC165 Input Expander).

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

Classes¶

Type	Name
struct	SYN_ShiftRegIn Input Shift Register Context.
struct	SYN_ShiftRegOut Output Shift Register Context.

Public Functions¶

Type	Name
bool	syn_shiftreg_in_get_bit (const SYN_ShiftRegIn * sr, uint16_t bit_index) Get logical state of a specific sampled input pin.
uint8_t	syn_shiftreg_in_get_byte (const SYN_ShiftRegIn * sr, uint8_t chip_index) Get sampled byte for a specific chip in the chain.
SYN_Status	syn_shiftreg_in_init (SYN_ShiftRegIn * sr, SYN_GPIO_Pin data_pin, SYN_GPIO_Pin clock_pin, SYN_GPIO_Pin load_pin, uint8_t num_chips) Initialize an Input Shift Register (74HC165).
void	syn_shiftreg_in_read (SYN_ShiftRegIn * sr) Pulse Parallel Load pin and clock in all input bits from hardware.
void	syn_shiftreg_in_set_bit_order (SYN_ShiftRegIn * sr, bool msb_first) Set bit order mode for input sampling.
void	syn_shiftreg_out_flush (SYN_ShiftRegOut * sr) Atomically flush buffer contents to physical hardware output pins.
SYN_Status	syn_shiftreg_out_init (SYN_ShiftRegOut * sr, SYN_GPIO_Pin data_pin, SYN_GPIO_Pin clock_pin, SYN_GPIO_Pin latch_pin, uint8_t num_chips) Initialize an Output Shift Register (74HC595).
void	syn_shiftreg_out_set_bit (SYN_ShiftRegOut * sr, uint16_t bit_index, bool state) Set logical state of a single pin in the shift register chain.
void	syn_shiftreg_out_set_bit_order (SYN_ShiftRegOut * sr, bool msb_first) Set bit order mode.
void	syn_shiftreg_out_set_enable (SYN_ShiftRegOut * sr, bool enable) Enable or disable outputs via Output Enable (OE) pin.
void	syn_shiftreg_out_set_oe_pin (SYN_ShiftRegOut * sr, SYN_GPIO_Pin oe_pin) Configure optional Output Enable (OE) pin.
void	syn_shiftreg_out_write_byte (SYN_ShiftRegOut * sr, uint8_t chip_index, uint8_t val) Set raw byte for a specific chip in the chain.

Macros¶

Type	Name
define	SYN_SHIFTREG_MAX_CHIPS `8`

Public Functions Documentation¶

function syn_shiftreg_in_get_bit¶

Get logical state of a specific sampled input pin.

bool syn_shiftreg_in_get_bit (
    const SYN_ShiftRegIn * sr,
    uint16_t bit_index
)

Parameters:

sr Shift register context.
bit_index Pin index (0 to num_chips*8 - 1).

Returns:

Logical state (true/false).

function syn_shiftreg_in_get_byte¶

Get sampled byte for a specific chip in the chain.

uint8_t syn_shiftreg_in_get_byte (
    const SYN_ShiftRegIn * sr,
    uint8_t chip_index
)

Parameters:

sr Shift register context.
chip_index Chip index (0 to num_chips-1).

Returns:

8-bit byte value.

function syn_shiftreg_in_init¶

Initialize an Input Shift Register (74HC165).

SYN_Status syn_shiftreg_in_init (
    SYN_ShiftRegIn * sr,
    SYN_GPIO_Pin data_pin,
    SYN_GPIO_Pin clock_pin,
    SYN_GPIO_Pin load_pin,
    uint8_t num_chips
)

Parameters:

sr Shift register context.
data_pin Serial Data In GPIO pin.
clock_pin Shift Clock GPIO pin.
load_pin Parallel Load GPIO pin.
num_chips Number of cascaded 8-bit chips (1 to 8).

Returns:

SYN_OK on success.

function syn_shiftreg_in_read¶

Pulse Parallel Load pin and clock in all input bits from hardware.

void syn_shiftreg_in_read (
    SYN_ShiftRegIn * sr
)

Parameters:

sr Shift register context.

function syn_shiftreg_in_set_bit_order¶

Set bit order mode for input sampling.

void syn_shiftreg_in_set_bit_order (
    SYN_ShiftRegIn * sr,
    bool msb_first
)

Parameters:

sr Shift register context.
msb_first True for MSB-first, false for LSB-first.

function syn_shiftreg_out_flush¶

Atomically flush buffer contents to physical hardware output pins.

void syn_shiftreg_out_flush (
    SYN_ShiftRegOut * sr
)

Parameters:

sr Shift register context.

function syn_shiftreg_out_init¶

Initialize an Output Shift Register (74HC595).

SYN_Status syn_shiftreg_out_init (
    SYN_ShiftRegOut * sr,
    SYN_GPIO_Pin data_pin,
    SYN_GPIO_Pin clock_pin,
    SYN_GPIO_Pin latch_pin,
    uint8_t num_chips
)

Parameters:

sr Shift register context.
data_pin Serial Data GPIO pin.
clock_pin Shift Clock GPIO pin.
latch_pin Latch / Storage Clock GPIO pin.
num_chips Number of cascaded 8-bit chips (1 to 8).

Returns:

SYN_OK on success.

function syn_shiftreg_out_set_bit¶

Set logical state of a single pin in the shift register chain.

void syn_shiftreg_out_set_bit (
    SYN_ShiftRegOut * sr,
    uint16_t bit_index,
    bool state
)

Parameters:

sr Shift register context.
bit_index Pin index (0 to num_chips*8 - 1).
state Logical state.

function syn_shiftreg_out_set_bit_order¶

Set bit order mode.

void syn_shiftreg_out_set_bit_order (
    SYN_ShiftRegOut * sr,
    bool msb_first
)

Parameters:

sr Shift register context.
msb_first True for MSB-first, false for LSB-first.

function syn_shiftreg_out_set_enable¶

Enable or disable outputs via Output Enable (OE) pin.

void syn_shiftreg_out_set_enable (
    SYN_ShiftRegOut * sr,
    bool enable
)

Parameters:

sr Shift register context.
enable True to enable outputs (OE LOW).

function syn_shiftreg_out_set_oe_pin¶

Configure optional Output Enable (OE) pin.

void syn_shiftreg_out_set_oe_pin (
    SYN_ShiftRegOut * sr,
    SYN_GPIO_Pin oe_pin
)

Parameters:

sr Shift register context.
oe_pin Output Enable GPIO pin.

function syn_shiftreg_out_write_byte¶

Set raw byte for a specific chip in the chain.

void syn_shiftreg_out_write_byte (
    SYN_ShiftRegOut * sr,
    uint8_t chip_index,
    uint8_t val
)

Parameters:

sr Shift register context.
chip_index Chip index (0 to num_chips-1).
val 8-bit byte value.

Macro Definition Documentation¶

define SYN_SHIFTREG_MAX_CHIPS¶

#define SYN_SHIFTREG_MAX_CHIPS `8`

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