Sensor Normalizer

main.c

//
//  main.c
//  Test
//
//  Created by Fabio Madge Pimentel on 28/08/14.
//  Copyright (c) 2014 Fabio Madge Pimentel. All rights reserved.
//

#include <stdio.h>
#include <stdint.h>
#include <string.h>
#include <stdbool.h>

#define MM_AMBIENT_LIGHT_READING     (20)
#define MM_LED_DIMM_ADDR             (30)
#define MM_LED_GLOBALCONFIG_BASE_ADDR   (31)
#define MM_LED_GLOBALCONFIG_CONFIG_ADDR   (37)
#define MM_LED0_BASE_ADDR    (64)
#define MM_LED1_BASE_ADDR    (80)
#define MM_LED2_BASE_ADDR    (96)
#define MM_LED3_BASE_ADDR    (112)

#define PIC_MAIN_I2C_ADDRESS              (0x0A)
#define PIC_LEFT_I2C_ADDRESS              (0x1A)
#define PIC_RIGHT_I2C_ADDRESS             (0x2A)

#define HALT_ON_ANIMATION_MSG (0)
#define HALT_OFF_ANIMATION_MSG (1)
#define HALT_PAIR_SUCCESS_ANIMATION_MSG (2)
#define UPDATE_BAT_LEVEL_MSG (3)
#define UPDATE_DIMM_LEVEL_MSG (4)

/* Timeouts used to set up the LED flashing pattern in ms */
#define ON_ANIMATION_TIME                  (4000)
#define OFF_ANIMATION_TIME                 (4000)
#define PAIR_SUCCESS_ANIMATION_TIME        (2000)
#define UPDATE_BAT_LEVEL_TIME              (1000)
#define UPDATE_DIMM_LEVEL_TIME              (500)

//const uint8_t sensor[] = {0x33, 0x33, 0x33, 0x33, 0x33, 0x33, 0x33, 0x33, 0x33, 0x33};
const uint8_t sensor[] = {0x33, 0x77, 0x77, 0x77, 0x77, 0x77, 0x77, 0x77, 0x27, 0x77, 0x77, 0x77, 0x77, 0x77, 0x77};

void updateDimmLevel(bool initialise);

int main(int argc, const char * argv[]) {
    
    printf("0\n");
    updateDimmLevel(true);
    
    for (uint8_t i = 1; i < sizeof(sensor); i++) {
        printf("%d\n", i);
        updateDimmLevel(false);
    }
    
    return 0;
}

void updateDimmLevel(bool initialise){
    static uint8_t measurements [4] = { 0 };
    static uint8_t oldestMeasurementPointer = 0;
    static uint8_t lastSent = 0;
    uint8_t level;
    uint8_t ev = 0;
    uint16_t var = 0; /* 4 * Var */
    
    static uint8_t pointer = 0;
    level = sensor[pointer++];
    
    /* level transformations */
    
    if (initialise) for(uint8_t i = 0; i < sizeof(measurements); i++) measurements[i] = level;
    else measurements[oldestMeasurementPointer] = level;
    
    /*Calculate expected value*/
    for(uint8_t i = 0; i < sizeof(measurements); i++){
        ev += measurements[i] >> 2;
    }
    
    /*Calculate Var*/
    for(uint8_t i = 0; i < sizeof(measurements); i++){
        int16_t temp = measurements[i];
        temp -= ev;
        var += temp*temp;
    }

    /* Var small enough for a reliable reading
     delta big enough to prevent unneccessary updates*/
    printf("var: %d, delta: %d, different: %s\n", var, (lastSent < ev ? ev - lastSent : lastSent - ev), lastSent != ev ? "true" : "false");
    if ((var < 100 && (lastSent < ev ? ev - lastSent : lastSent - ev) > 6) || initialise)
    {
        lastSent = ev;
        printf("The dimm level was updated to 0x%X.\n", level);
    }
    
    oldestMeasurementPointer = ++oldestMeasurementPointer >= sizeof(measurements) ? 0 : oldestMeasurementPointer;
}