Refactor pcf8574 code

This commit is contained in:
Sanchayan Maity 2017-04-28 11:25:01 +05:30
parent 1f76a72c2b
commit 4619d3819c
3 changed files with 175 additions and 162 deletions

104
pcf8574/main.c Normal file
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#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <unistd.h>
#include "pcf8574.h"
/* See the Pioneer 600 Schematic */
static uint8_t LED_ON = 0xEF;
static uint8_t LED_OFF = 0xFF;
static uint8_t BUZZER_ON = 0x7F;
static uint8_t BUZZER_OFF = 0xFF;
void pioneer600_led2_on(i2c *i2c)
{
pcf8574_port_write(i2c, LED_ON);
}
void pioneer600_led2_off(i2c *i2c)
{
pcf8574_port_write(i2c, LED_OFF);
}
void pioneer600_buzzer_on(i2c *i2c)
{
pcf8574_port_write(i2c, BUZZER_ON);
}
void pioneer600_buzzer_off(i2c *i2c)
{
pcf8574_port_write(i2c, BUZZER_OFF);
}
void pioneer600_read_joystick(i2c *i2c)
{
uint8_t port;
port = pcf8574_port_read(i2c);
if (!(port & 0x01))
printf("Key A pressed\n");
else if (!(port & 0x02))
printf("Key B pressed\n");
else if (!(port & 0x04))
printf("Key C pressed\n");
else if (!(port & 0x08))
printf("Key D pressed\n");
else if (port & 0x0F)
printf("No keys pressed\n");
}
int main(void)
{
i2c *i2c_pcf8574;
uint8_t led_status = LED_OFF;
uint8_t buzzer_status = BUZZER_OFF;
uint32_t input;
uint8_t ret = 0;
i2c_pcf8574 = pcf8574_init(0, PCF8574_ADDRESS);
if (i2c_pcf8574 == NULL)
return EXIT_FAILURE;
while (true) {
printf("\nEnter choice: 1. Joy stick status 2. Led On/Off 3. Buzzer On/Off 4. Exit\n");
scanf("%d", &input);
switch (input) {
case 1:
pioneer600_read_joystick(i2c_pcf8574);
break;
case 2:
if (led_status == LED_OFF) {
pioneer600_led2_on(i2c_pcf8574);
led_status = LED_ON;
} else {
pioneer600_led2_off(i2c_pcf8574);
led_status = LED_OFF;
}
break;
case 3:
if (buzzer_status == BUZZER_OFF) {
pioneer600_buzzer_on(i2c_pcf8574);
buzzer_status = BUZZER_ON;
} else {
pioneer600_buzzer_off(i2c_pcf8574);
buzzer_status = BUZZER_OFF;
}
break;
case 4:
goto exit;
break;
default:
printf("Enter valid input\n");
break;
}
}
exit:
ret = pcf8574_free(i2c_pcf8574);
if (ret == EXIT_FAILURE)
perror("Failed to close I2C port");
return 0;
}

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/*
* pcf8574.c
* PCF8574 IO expander helper functions using libsoc API.
*
* libsoc i2c API Documentation: http://jackmitch.github.io/libsoc/c/i2c/#i2c
*
* Copyright (C) 2017 - BhuvanChandra DV <bhuvanchandradv@gmail.com>
*
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <unistd.h>
#include <stdint.h>
#include <stdbool.h>
#include <libsoc_i2c.h>
/* PCF8574 I2C Address on Pioneer 600 */
#define PCF8574_ADDRESS 0x20
static uint8_t LED_ON = 0xEF;
static uint8_t LED_OFF = 0xFF;
static uint8_t BUZZER_ON = 0x7F;
static uint8_t BUZZER_OFF = 0xFF;
/*
* libsoc i2c API Documentation: http://jackmitch.github.io/libsoc/c/i2c/#i2c
*/
#include "pcf8574.h"
i2c* pcf8574_init(uint8_t i2c_bus, uint8_t i2c_address)
{
i2c *i2c;
uint8_t ret;
uint8_t buf[1] = {0};
i2c *i2c = libsoc_i2c_init(i2c_bus, i2c_address);
i2c = libsoc_i2c_init(i2c_bus, i2c_address);
if (i2c == NULL) {
perror("libsoc_i2c_init failed");
return i2c;
}
/*
* http://cache.nxp.com/documents/data_sheet/PCF8574_PCF8574A.pdf
* See Page 7 of the data sheet Quasi-bidirectional I/Os
* Default all expander pins as input
*/
buf[0] = 0xff;
ret = libsoc_i2c_write(i2c, buf, 1);
if (ret == EXIT_FAILURE) {
perror("PCF8574 initialization failed");
libsoc_i2c_free(i2c);
return NULL;
}
return i2c;
}
int pcf8574_close(i2c *i2c)
int pcf8574_free(i2c *i2c)
{
return libsoc_i2c_free(i2c);
}
int pioneer600_led2_on(i2c *i2c)
uint8_t pcf8574_port_read(i2c *i2c)
{
uint8_t ret;
uint8_t buf[1] = {0};
uint8_t res;
buf[0] = LED_ON;
ret = libsoc_i2c_write(i2c, buf, 1);
if (ret == EXIT_FAILURE)
perror("I2C write failed");
if (libsoc_i2c_read(i2c, &res, 1))
return 0;
return ret;
return res;
}
int pioneer600_led2_off(i2c *i2c)
size_t pcf8574_port_read_buf(i2c *i2c, void *buf, size_t len)
{
uint8_t ret;
uint8_t buf[1] = {0};
uint8_t *_buf = (uint8_t *)buf;
buf[0] = LED_OFF;
ret = libsoc_i2c_write(i2c, buf, 1);
if (ret == EXIT_FAILURE)
perror("I2C write failed");
if (!len || !buf)
return 0;
return ret;
if (libsoc_i2c_read(i2c, _buf, len))
return 0;
return len;
}
int pioneer600_buzzer_on(i2c *i2c)
size_t pcf8574_port_write_buf(i2c *i2c, void *buf, size_t len)
{
uint8_t ret;
uint8_t buf[1] = {0};
uint8_t *_buf = (uint8_t *)buf;
buf[0] = BUZZER_ON;
ret = libsoc_i2c_write(i2c, buf, 1);
if (ret == EXIT_FAILURE)
perror("I2C write failed");
if (!len || !buf)
return 0;
return ret;
if (libsoc_i2c_write(i2c, _buf, len))
return 0;
return len;
}
int pioneer600_buzzer_off(i2c *i2c)
void pcf8574_port_write(i2c *i2c, uint8_t value)
{
uint8_t ret;
uint8_t buf[1] = {0};
buf[0] = BUZZER_OFF;
ret = libsoc_i2c_write(i2c, buf, 1);
if (ret == EXIT_FAILURE)
perror("I2C write failed");
return ret;
libsoc_i2c_write(i2c, &value, 1);
}
void pioneer600_read_joystick(i2c *i2c)
bool pcf8574_gpio_read(i2c *i2c, uint8_t num)
{
uint8_t ret;
uint8_t buf[1] = {0};
ret = libsoc_i2c_read(i2c, buf, 1);
if (ret == EXIT_FAILURE)
perror("I2C read failed");
else {
if (buf[0] & 0x0F)
printf("No keys pressed\n");
if (!(buf[0] & 0x01))
printf("Key A pressed\n");
if (!(buf[0] & 0x02))
printf("Key B pressed\n");
if (!(buf[0] & 0x04))
printf("Key C pressed\n");
if (!(buf[0] & 0x08))
printf("Key D pressed\n");
}
return;
return (bool)((pcf8574_port_read(i2c) >> num) & 1);
}
int main(void)
void pcf8574_gpio_write(i2c *i2c, uint8_t num, bool value)
{
i2c *i2c_pcf8574;
uint8_t led_status = LED_OFF;
uint8_t buzzer_status = BUZZER_OFF;
uint32_t input;
uint8_t ret = 0;
uint8_t bit = (uint8_t)!value << num;
uint8_t mask = ~(1 << num);
i2c_pcf8574 = pcf8574_init(0, PCF8574_ADDRESS);
if (i2c_pcf8574 == NULL)
return EXIT_FAILURE;
while (true) {
printf("\nEnter choice: 1. Joy stick status 2. Led On/Off 3. Buzzer On/Off 4. Exit\n");
scanf("%d", &input);
switch (input) {
case 1:
pioneer600_read_joystick(i2c_pcf8574);
break;
case 2:
if (led_status == LED_OFF) {
ret = pioneer600_led2_on(i2c_pcf8574);
if (ret == EXIT_FAILURE)
printf("Led turn on failed\n");
else {
led_status = LED_ON;
printf("Led On\n");
}
} else {
ret = pioneer600_led2_off(i2c_pcf8574);
if (ret == EXIT_FAILURE)
printf("Led turn off failed\n");
else {
led_status = LED_OFF;
printf("Led Off\n");
}
}
break;
case 3:
if (buzzer_status == BUZZER_OFF) {
ret = pioneer600_buzzer_on(i2c_pcf8574);
if (ret == EXIT_FAILURE)
printf("Buzzer turn on failed\n");
else {
buzzer_status = BUZZER_ON;
printf("Buzzer On\n");
}
} else {
ret = pioneer600_buzzer_off(i2c_pcf8574);
if (ret == EXIT_FAILURE)
printf("Buzzer turn off failed\n");
else {
buzzer_status = BUZZER_OFF;
printf("Buzzer Off\n");
}
}
break;
case 4:
goto exit;
break;
default:
printf("Enter valid input\n");
break;
}
}
exit:
ret = pcf8574_close(i2c_pcf8574);
if (ret == EXIT_FAILURE)
perror("Failed to close I2C port");
return 0;
pcf8574_port_write (i2c, (pcf8574_port_read(i2c) & mask) | bit);
}

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pcf8574/pcf8574.h Normal file
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/*
* pcf8574.h
*
* Created on: Apr 28, 2017
* Author: sanchayan
*/
#ifndef PCF8574_H_
#define PCF8574_H_
#include <stddef.h>
#include <stdint.h>
#include <stdbool.h>
#include <libsoc_i2c.h>
/* PCF8574 I2C Address on Pioneer 600 */
#define PCF8574_ADDRESS 0x20
i2c* pcf8574_init(uint8_t i2c_bus, uint8_t i2c_address);
int pcf8574_free(i2c *i2c);
uint8_t pcf8574_port_read(i2c *i2c);
size_t pcf8574_port_read_buf(i2c *i2c, void *buf, size_t len);
void pcf8574_port_write(i2c *i2c, uint8_t value);
size_t pcf8574_port_write_buf(i2c *i2c, void *buf, size_t len);
bool pcf8574_gpio_read(i2c *i2c, uint8_t num);
void pcf8574_gpio_write(i2c *i2c, uint8_t num, bool value);
#endif /* PCF8574_H_ */