gmaFootWeightLimit/gmaFootWeightLimit.ino

// gmaFootWeightLimit
// (c) 2013 by Gottfried Mayer, www.gma.name
// measures weight on foot and displays it as immediate value and 5 second average

// configuration area
float weightLimit = 60;  // weight in kg

uint16_t eightyWeight = 522;  // analog Value at 80kg   //History: 477
// 10 kg = 65 --- 80 kg = 530

uint8_t limit1Start = 60; // 80% - must be below 100%
uint8_t limit2Start = 80; // 90% - must be below 100%
#define MAXBRIGHT 20     // maximum brightness of LED
#define MAXWARNBRIGHT 60 // maximum warning brightness of LED
#define maxWeightHoldTime 2500 // hold time for peak values


//uncomment this for debug over serial port
//#define SerialDebug

#ifdef SerialDebug
#include <Streaming.h>
#endif

#include <FastSPI_LED.h>
#define NUM_LEDS 2
struct CRGB { unsigned char r; unsigned char g; unsigned char b; };
struct CRGB *led;

uint16_t zeroWeight;
uint16_t limitWeight;
uint16_t limit1Weight;
uint16_t limit2Weight;
uint16_t maxWeight;
uint32_t lastMaxWeight;
uint8_t  hasMaxWarning = 0;

float avgWeight;

#define WEIGHTPIN A6


void setup()
{
  FastSPI_LED.setLeds(NUM_LEDS);
  FastSPI_LED.setChipset(CFastSPI_LED::SPI_LPD6803);
  FastSPI_LED.init();
  FastSPI_LED.start();
  led = (struct CRGB*)FastSPI_LED.getRGBData();
  led[0] = GetColor(0,0,MAXBRIGHT);
  led[1] = GetColor(0,0,MAXBRIGHT);  
  FastSPI_LED.show();
  led[0] = GetColor(0,0,0);
  led[1] = GetColor(0,0,0);
  // measure zero weight
  int32_t zWeight[10];
  for ( uint8_t i = 0; i<10; i++) {
    zWeight[i] = analogRead(WEIGHTPIN);
    delay(20);
  }
  zeroWeight = (zWeight[0] + zWeight[1] + zWeight[2] + zWeight[3] + zWeight[4] +
                zWeight[5] + zWeight[6] + zWeight[7] + zWeight[8] + zWeight[9]) / 10;

  uint16_t iWeightLimit = (eightyWeight / 80.0) * weightLimit;
  limitWeight = zeroWeight + iWeightLimit;
  limit1Weight = zeroWeight + (iWeightLimit * (float(limit1Start) / 100.0));
  limit2Weight = zeroWeight + (iWeightLimit * (float(limit2Start) / 100.0));
  avgWeight = zeroWeight;
  maxWeight = zeroWeight;
  
  #ifdef SerialDebug
  Serial.begin(9600);
  Serial << "Setup done" << endl;
  Serial << "0W=" << zeroWeight << " !W=" << limitWeight << " RW=" << limitRWeight << " GW=" << limitGWeight << endl;
  #endif
  
}

void loop() {
  
  //uint16_t currWeight = random(limitRWeight,limitWeight+10);
  uint16_t currWeight = analogRead(WEIGHTPIN);
  led[1] = showWeight(currWeight,MAXBRIGHT);
  //avgWeight = avgWeight + ((currWeight - avgWeight) / 250.0);  // 20 * 250 = 5000 --- 5 second average
  //led[0] = showWeight(avgWeight,MAXBRIGHT);
  
  if (currWeight > limit1Weight) {
    if(currWeight > maxWeight) {
      maxWeight = currWeight;
      lastMaxWeight = millis();
      hasMaxWarning = 1;
    }
  }
  
  if(hasMaxWarning == 1) {
    if(lastMaxWeight + maxWeightHoldTime < millis()) {
      maxWeight = currWeight;
      hasMaxWarning = 0;
      led[0] = GetColor(0,0,0);
    } else {
      led[0] = showWeight(maxWeight, MAXWARNBRIGHT);
    }
  }
  
  FastSPI_LED.show();
  
  
  delay(20);
  
  #ifdef SerialDebug
  //Serial << "curr=" << currWeight << " avg=" << avgWeight << " 0=" << zeroWeight << endl;
  Serial << "curr=" << currWeight << " 0=" << zeroWeight << endl;
  delay(200);
  #endif
  

  // test
  /*
  for ( uint16_t i = zeroWeight; i <= limitWeight+100; i++) {
    led[1] = showWeight(i,MAXBRIGHT);
    if( i % 2 == 0) {
      led[0] = GetColor(0,0,0);
    } else {
      led[0] = GetColor(0,0,10);
    }
    FastSPI_LED.show();
    delay(20);
  }
  */

}

struct CRGB showWeight(uint16_t w, uint8_t brightness) {
  struct CRGB ret;
  if(w < zeroWeight) {
    ret = GetColor(0,0,0);
  } else {
    if(w < limit1Weight) {
      //ret = GetColor(0,0,brightness);
      ret = GetColor(0,0,0);
      ret.r = map(w, zeroWeight,zeroWeight+((limit1Weight-zeroWeight)/2),0,brightness);
      ret.g = map(w, zeroWeight,zeroWeight+((limit1Weight-zeroWeight)/2),0,brightness);
    } else {
      if(w >= limitWeight) {
        ret = GetColor(0,0,brightness); // blue
      } else {
        ret = GetColor(0,brightness,0); // green
        if(w >= limit2Weight) {
          ret.b = map(w,limit2Weight,limitWeight,0,brightness); // add some blue just for effect...
        }
      }
    }
  }
  return(ret);
}


struct CRGB GetColor(uint8_t r, uint8_t g, uint8_t b) {
  struct CRGB ret;
  ret.r = r;
  ret.g = g;
  ret.b = b;
  return(ret);
}