amb_tsl2591.c

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#include "amb_tsl2591.h"
 
#ifdef SENSOR_AMB_TSL2591
 
#include "i2c.h"
#include "utils/mydefs.h"
#include "mymems.h"
#include <stdio.h>
 
#define AMBIENT_ADDR      (0x29 << 1) // Shifted for HAL
#define TSL2591_COMMAND   0xA0        // Must be OR'd with register address
#define REG_ENABLE        0x00
#define REG_CONFIG        0x01
#define REG_C0DATAL       0x14        // Channel 0 (Visible + IR)
#define REG_C1DATAL       0x16        // Channel 1 (IR)
 
#define THRESH_MAX 60000
#define THRESH_MIN 500
 
// First, we define the gain multipliers and the threshold for switching. The TSL2591 supports specific gain steps.
typedef enum
{
    TSL2591_GAIN_LOW = 0x00, // 1x (Bright light)
    TSL2591_GAIN_MED = 0x10, // 25x
    TSL2591_GAIN_HIGH = 0x20, // 428x
    TSL2591_GAIN_MAX = 0x30  // 9876x (Very dark)
} TSL2591_Gain_t;
 
// Global or static variable to track state
static TSL2591_Gain_t _currentGain = TSL2591_GAIN_MED;
static int8_t _isAmbientSensor = 0; // indicator whether sensor is present
amb_tsl2591_t _amb_tsl2591Data = { };
amb_tsl2591_t _bck_amb_tsl2591Data = {};    // backup
 
int8_t amb_tsl2591_Is(I2C_HandleTypeDef *hi2c, int8_t tryInit) //
{
    if (!_isAmbientSensor && tryInit)
        amb_tsl2591_Init(hi2c);
    return _isAmbientSensor;
}
 
HAL_StatusTypeDef amb_tsl2591_IsOn(I2C_HandleTypeDef *hi2c, uint8_t *onOff)
{
    uint8_t data = 0;
    HAL_StatusTypeDef status = HAL_ERROR;
 
    if (_isAmbientSensor)
    {
        status = HAL_I2C_Mem_Read(hi2c, AMBIENT_ADDR, TSL2591_COMMAND | REG_ENABLE, I2C_MEMADD_SIZE_8BIT, &data, 1, 100);
        if (status == HAL_OK)
            if (onOff != NULL)
                *onOff = data & 1; //(bit0 - powerOnOff);
    }
    return status;
}
 
HAL_StatusTypeDef amb_tsl2591_On(I2C_HandleTypeDef *hi2c)
{
    HAL_StatusTypeDef status = HAL_ERROR;
    uint8_t data;
 
    _amb_tsl2591Data.IsDataValid = 0;
    if (_isAmbientSensor)
    {
        do
        {
            // 1. Power on the sensor (Enable register)
            // AIEN (Bit 4) = 0 (Interrupts off for now)
            // AEN  (Bit 1) = 1 (ALS Enable)
            // PON  (Bit 0) = 1 (Power ON)
            data = 0x03;
            status = HAL_I2C_Mem_Write(hi2c, AMBIENT_ADDR, TSL2591_COMMAND | REG_ENABLE, I2C_MEMADD_SIZE_8BIT, &data, 1, 100);
            if (status != HAL_OK)
                break;
 
            // 2. Set Initial Gain and Timing (Config register)
            // We match our 'currentGain' variable (TSL2591_GAIN_MED = 0x10)
            // And set Integration Time to 100ms (0x01)
            // Result: 0x11
            _currentGain = TSL2591_GAIN_MED;
            data = (uint8_t) _currentGain | 0x01;
 
            status = HAL_I2C_Mem_Write(hi2c, AMBIENT_ADDR, TSL2591_COMMAND | REG_CONFIG, I2C_MEMADD_SIZE_8BIT, &data, 1, 100);
            if (status != HAL_OK)
                break;
            status = HAL_OK;
            if (_isAmbientSensor)
            {
                for (data = 0; data < 4; data++)
                    if (amb_tsl2591_Read(hi2c) == HAL_OK)
                        break;  // calibration...., if value obtained, can finish
            }
            _memsMainBlock.Sens_AmbientStart++;
            mems_WriteMainBlock();
        } while (0);
        _isAmbientSensor = (status == HAL_OK);
    }
    return status;
}
 
HAL_StatusTypeDef amb_tsl2591_Off(I2C_HandleTypeDef *hi2c)
{
    HAL_StatusTypeDef status = HAL_ERROR;
    uint8_t data;
 
    if (_isAmbientSensor)
        do
        {
            // 1. Power on the sensor (Enable register)
            // AIEN (Bit 4) = 0 (Interrupts off for now)
            // AEN  (Bit 1) = 0 (ALS Enable)
            // PON  (Bit 0) = 0 (Power ON)
            data = 0x00;
            status = HAL_I2C_Mem_Write(hi2c, AMBIENT_ADDR, TSL2591_COMMAND | REG_ENABLE, I2C_MEMADD_SIZE_8BIT, &data, 1, 100);
            if (status != HAL_OK)
                break;
        } while (0);
    return status;
}
 
HAL_StatusTypeDef amb_tsl2591_Init(I2C_HandleTypeDef *hi2c)
{
    HAL_StatusTypeDef status = I2C_IsDeviceReadyMT(hi2c, AMBIENT_ADDR, 2, 2);   // first check
    if (status == HAL_OK)
        do
        {
            _isAmbientSensor = 1;
            // 1. turn on sensor and calibrate
            if ((status = amb_tsl2591_On(hi2c)) != HAL_OK)
                break;
            // 2. turn off sensor
            if ((status = amb_tsl2591_Off(hi2c)) != HAL_OK)
                break;
        } while (0);
    _isAmbientSensor = (status == HAL_OK);
    return status;
}
 
/**
 * @brief This function checks the raw channel 0 value. If it is near the 16-bit limit (65535), it drops the gain. If it is too low, it boosts it.
 */
static HAL_StatusTypeDef ambient_AdjustGain(I2C_HandleTypeDef *hi2c, uint16_t rawCH0)
{
    TSL2591_Gain_t newGain = _currentGain;
    HAL_StatusTypeDef status = HAL_OK;
 
    // Thresholds: ~90% of max for "too bright", ~1% for "too dark"
    if (rawCH0 > THRESH_MAX) // 60000) //
    {
        if (_currentGain == TSL2591_GAIN_MAX)
            newGain = TSL2591_GAIN_HIGH;
        else if (_currentGain == TSL2591_GAIN_HIGH)
            newGain = TSL2591_GAIN_MED;
        else if (_currentGain == TSL2591_GAIN_MED)
            newGain = TSL2591_GAIN_LOW;
    }
    else if (rawCH0 < THRESH_MIN) ///500)
    {
        if (_currentGain == TSL2591_GAIN_LOW)
            newGain = TSL2591_GAIN_MED;
        else if (_currentGain == TSL2591_GAIN_MED)
            newGain = TSL2591_GAIN_HIGH;
        else if (_currentGain == TSL2591_GAIN_HIGH)
            newGain = TSL2591_GAIN_MAX;
    }
 
    if (newGain != _currentGain) //
    {
        _currentGain = newGain;
        uint8_t regVal = _currentGain | 0x01; // 0x01 is 100ms integration time
        status = HAL_I2C_Mem_Write(hi2c, AMBIENT_ADDR, TSL2591_COMMAND | REG_CONFIG, I2C_MEMADD_SIZE_8BIT, &regVal, 1, 100);
    }
    return status;
}
 
/**
 * @brief When calculating Lux, you must use the actual multiplier corresponding to the currentGain
 */
HAL_StatusTypeDef amb_tsl2591_Read(I2C_HandleTypeDef *hi2c) //
{
    uint8_t buffer[4];
    HAL_StatusTypeDef status = HAL_ERROR;
 
    if (_isAmbientSensor) //
    {
        do
        {
            uint8_t onOff = 0;
            // 1.check, sensor is on
            if ((status = amb_tsl2591_IsOn(hi2c, &onOff)) != HAL_OK)
                break;
 
            if (!onOff)
            {
                status = HAL_TIMEOUT;
                break;
            }
 
            // Read raw values
            if ((status = HAL_I2C_Mem_Read(hi2c, AMBIENT_ADDR, TSL2591_COMMAND | REG_C0DATAL, I2C_MEMADD_SIZE_8BIT, buffer, 4, 100)) != HAL_OK)
                break;
 
            uint16_t ch0 = (buffer[1] << 8) | buffer[0];
            uint16_t ch1 = (buffer[3] << 8) | buffer[2];
 
            // 1. Update gain for the NEXT reading
            ambient_AdjustGain(hi2c, ch0);
 
            // 2. Map current gain enum to actual multiplier for math
            float multiplier;
            switch (_currentGain)
            //
            {
                case TSL2591_GAIN_LOW:
                    multiplier = 1.0f;
                break;
                case TSL2591_GAIN_MED:
                    multiplier = 25.0f;
                break;
                case TSL2591_GAIN_HIGH:
                    multiplier = 428.0f;
                break;
                case TSL2591_GAIN_MAX:
                    multiplier = 9876.0f;
                break;
                default:
                    multiplier = 1.0f;
            }
 
            // 3. Calculate Lux
            float atime = 100.0f;
            float cpl = (atime * multiplier) / 408.0f;
            if (ch0 < THRESH_MIN || ch0 > THRESH_MAX)
            {
                status = HAL_BUSY;
                break;
            }
            status = HAL_OK;
            _amb_tsl2591Data.IsDataValid = 1;
            _amb_tsl2591Data.Lux = ((float) ch0 - (2.0f * (float) ch1)) / cpl;
            if (_amb_tsl2591Data.Lux < 0)
                _amb_tsl2591Data.Lux = 0.0f;
        } while (0);
    }
    return status;
}
 
void amb_tsl2591_LogData(char* buf)
{
    if (buf != NULL)
        sprintf(buf, "|ambient lux:" PRIf_02 " ", PRIf_02D(_amb_tsl2591Data.Lux));
}
 
#endif