max44009.h

#ifndef __MAX44009_H__
#define __MAX44009_H__

#include "hal_i2c_m_sync.h" // device specific IO functions
#include <stdint.h>

/**
 * 7-bit I2C slave address depends on the state of pin A0 (GND or VCC)
 * R/W bit is the LSB of the address, with these addresses shifted left one bit.
 */
typedef enum {
    LIGHT_ADD_GND            = 0x4A,
    LIGHT_ADD_VCC            = 0x4B,
} MAX44009_ADDR_t;

/** @brief initializes the data structures and hardware interfaces
 *
 * This function initializes the sensor interface with the I2C interface
 * to use and the address of the sensor. The address has only two valid inputs
 * based on MAX44009_ADDR_t enum but this is not checked in this function.
 *
 * @param WIRE_I2C device data structure to use for talking to the sensor
 * @param ADDR Address of the sensor (see MAX44009_ADDR_t enum)
 * @return Return ERR_NONE if successful, or a system error
 */
int32_t max44009_init(struct i2c_m_sync_desc* const WIRE_I2C, const uint8_t ADDR);

/** @brief Configures the max44009 light sensor
 *
 * This function sets all configuration settings at once to reduce I2C traffic.
 * the parameter should be a bitwise OR of all the settings defined in the
 * configurations enumerations.
 *
 * @param configuration bitwise OR of the configuration settings
 * @return Return ERR_NONE if successful, or a system error
 */
int32_t max44009_configure(const uint8_t configuration);

/** @brief Enables the interrupt output of the sensor
 *
 * Please note that this function only enables the interrupt on the sensor,
 * and for now does not set up the local detection of that interrupt.
 * Use enumeration values in LIGHT_ISR_ENABLED_t to set value.
 *
 * @param enable enable or disable ISR with enum or literal 0x00 and 0x01
 * @return Return ERR_NONE if successful, or a system error
 */
int32_t max44009_isr(const uint8_t enable);

/** @brief Gets the most recent reading from the sensor without decoding
 *
 * The sensor works by continuously sampling and storing the latest sample
 * into a register that can be read at any time. This function retrieves the
 * latest sample from that register. This function returns the exponent and the mantissa in one
 * 16 bit integer to reduce computational time. bits 0-7 are the mantissa and bits 8-11 are the
 * exponent. The high 4 bits will be set to 0.
 *
 * @param reading [OUT] the light value from the sensor with the LSB as the mantissa and the MSB as the exponent
 * @return ERR_NONE if successful, system error value if failure.
 */
int32_t max44009_read(uint16_t* luxVal);

/** @brief Gets the most recent reading from the sensor without decoding
 *
 * This function returns the lux value as an unsigned integer, discarding
 * the decimal portion of the value. Lux can range from 0 to 188,006.
 *
 * @return the light value from the sensor with the LSB as the mantissa and the MSB as the exponent
 */
uint32_t max44009_lux_integer(const uint16_t reading);

/** @brief Gets the most recent reading from the sensor
 *
 * This function returns the Lux value as an floating point value,
 * discarding the decimal portion of the value.
 * Lux can range from 0 to 188,006.
 *
 * @param reading [IN] a raw reading from the sensor
 * @return the light value from the sensor as a float value in lux
 */
float max44009_lux_float(const uint16_t reading);

/** @brief Sets up the interrupt detection window
 *
 * This function sets up the light change detection
 * window. This function DOES NOT enable the interrupt,
 * which needs to be enabled or disabled separately.
 *
 * @param upper The upper threshold (high byte)
 * @param lower The lower threshold (high byte)
 * @param timer The amount of time (in 100ms increments) light needs to be outside the window to trigger the interrupt
 * @return True if successful, false if not. Any error is likely due to I2C
 */
bool max44009_set_window(const uint8_t upper, const uint8_t lower, const uint8_t timer);

#endif    /* __MAX44009_H__ */