main.c

/*
 * Copyright (c) 2018 Tavish Naruka <tavishnaruka@gmail.com>
 *
 * SPDX-License-Identifier: Apache-2.0
 */

#include <logging/log_ctrl.h>

#include <errno.h>
#include <zephyr.h>
#include <sys/printk.h>
#include <device.h>
#include <drivers/i2c.h>

#include <logging/log.h>

#ifdef ARDUINO_I2C_LABEL
#define I2C_DEV ARDUINO_I2C_LABEL
#else
#define I2C_DEV "I2C_0"
#endif

LOG_MODULE_REGISTER(main);

/**
 * @file This app scans I2C bus for any devices present
 */

#define PFC8574_MAX_ADDR 0x38
#define PCF8574_MAX_PIN 8
#define PFC8574_STATUS_PIN_ON 1
#define PFC8574_STATUS_PIN_OFF 0

#define COUNT(X) (sizeof((X)) / sizeof((X)[0]))

bool pfc8574_is_valid_pin(struct device *dev, int pin)
{
	if ((pin > PCF8574_MAX_PIN) || (pin < 0))
	{
		LOG_ERR("Pin %d is invalid", pin);
		return false;
	}

	return true;
}

int pfc8674_write(struct device *dev, uint16_t *data)
{
	struct i2c_msg wrt[] = {
			{.buf = data,
			 .len = sizeof(*data),
			 .flags = I2C_MSG_WRITE | I2C_MSG_STOP}};

	int result = i2c_transfer(dev, wrt, COUNT(wrt), PFC8574_MAX_ADDR);
	LOG_DBG("Write result (%d)", result);
	return result;
}

// int pfc8574_pinmode(struct device *dev, int pin, int mode)
// {
// 	if (!pfc8574_is_valid_pin(dev, pin))
// 	{
// 		return -1;
// 	}

// 	LOG_DBG("%d is valid pin.", pin);
// 	if (pin == 0)
// 	{
// 		LOG_DBG("Applying for all pins since pin is 0.");
// 		for (int i = 1; i <= PCF8574_MAX_PIN; i++)
// 		{
// 			pfc8574_pinmode(dev, i, mode);
// 		}
// 	}
// 	else
// 	{
// 		LOG_DBG("Toggling pin %d/%d", pin, mode);
// 		// i2c_transfer(dev, )

// 		union {
// 			uint8_t bytes[2];
// 			uint16_t word;
// 		} tbw = {
// 				.bytes = {(1 << pin), (1 << pin)}};

// 		// i2c_transfer(dev, msgs[0])
// 		return pfc8674_write(dev, &tbw.word);
// 	}

// 	return 0;
// }

int pfc8574_pinmode(struct device *dev, int pin, int mode)
{
	LOG_DBG("Toggling pin %d -> %d", pin, mode);
	// i2c_transfer(dev, )

	union {
		uint8_t bytes[2];
		uint16_t word;
	} tbw = {
			.bytes = {(mode << pin), (mode << pin)}};

	// i2c_transfer(dev, msgs[0])
	return pfc8674_write(dev, &tbw.word);

	return 0;
}

int pfc8574_disable_all(struct device *dev)
{
	LOG_DBG("Disable all pins");
	// i2c_transfer(dev, )

	union {
		uint8_t bytes[2];
		uint16_t word;
	} tbw = {
			.bytes = {0, 0}};

	// i2c_transfer(dev, msgs[0])
	return pfc8674_write(dev, &tbw.word);

	return 0;
}

int pfc8574_read(struct device *dev, int pin, bool *dst)
{
	uint8_t rd;
	int result = i2c_read(dev, &rd, sizeof(rd), PFC8574_MAX_ADDR);

	LOG_DBG("Read result is (%d)", result);

	if (result != 0)
	{
		return result;
	}

	if (dst)
	{
		*dst = (rd & (1 << pin)) > 0;
	}

	// LOG_DBG("%x", buf[0]);

	return 0;
}

void main(void)
{
	struct device *pfc8574_dev;

	LOG_INF("Starting i2c scanner...\n");

	pfc8574_dev = device_get_binding(I2C_DEV);
	if (!pfc8574_dev)
	{
		LOG_ERR("I2C: Device driver not found.\n");
		return;
	}

	LOG_INF("Now running");

	for (u8_t i = 4; i <= 0x77; i++)
	{
		struct i2c_msg msgs[1];
		u8_t dst;

		/* Send the address to read from */
		msgs[0].buf = &dst;
		msgs[0].len = 0U;
		msgs[0].flags = I2C_MSG_WRITE | I2C_MSG_STOP;

		if (i2c_transfer(pfc8574_dev, &msgs[0], 1, i) == 0)
		{
			printk("0x%2x FOUND\n", i);
		}
	}

	pfc8574_pinmode(pfc8574_dev, 1, 1);

	bool state = 0;
	int pin_state;

	// while (true)
	// {
	// 	pfc8574_pinmode(pfc8574_dev, 0, (int)state);
	// 	state = !state;
	// 	LOG_INF("State %d", state);

	// 	pfc8574_read(pfc8574_dev, 1, &pin_state);

	// 	printk("%i\n", pin_state);
	// 	LOG_INF("Sleepin 1 sec");

	// 	k_sleep(4 * 1000);
	// }
	pfc8574_disable_all(pfc8574_dev);

	while (true)
	{
		for (int i = 0; i < 8; i++)
		{
			pfc8574_pinmode(pfc8574_dev, i, 1);
		}

		state = !state;
		k_sleep(2 * 1000);
	}
}