So im making a device to measure salinity for science olympiad detector build. But I need 3 leds to turn on when the value of the salinity (ppm) hits a certain number and must turn off and turn there other led when it does hit the next range of values. How do i Code this?
Right Now my code is :
#define TdsSensorPin A0
#define VREF 5.0 // analog reference voltage(Volt) of the ADC
#define SCOUNT 30 // sum of sample point
int analogBuffer[SCOUNT]; // store the analog value in the array, read from ADC
int analogBufferTemp[SCOUNT];
int analogBufferIndex = 0;
int copyIndex = 0;
float averageVoltage = 0;
float tdsValue = 0;
float temperature = 16; // current temperature for compensation
// median filtering algorithm
int getMedianNum(int bArray[], int iFilterLen){
int bTab[iFilterLen];
for (byte i = 0; i<iFilterLen; i++)
bTab[i] = bArray[i];
int i, j, bTemp;
for (j = 0; j < iFilterLen - 1; j++) {
for (i = 0; i < iFilterLen - j - 1; i++) {
if (bTab[i] > bTab[i + 1]) {
bTemp = bTab[i];
bTab[i] = bTab[i + 1];
bTab[i + 1] = bTemp;
}
}
}
if ((iFilterLen & 1) > 0){
bTemp = bTab[(iFilterLen - 1) / 2];
}
else {
bTemp = (bTab[iFilterLen / 2] + bTab[iFilterLen / 2 - 1]) / 2;
}
return bTemp;
}
void setup(){
Serial.begin(115200);
pinMode(TdsSensorPin,INPUT);
}
void loop(){
static unsigned long analogSampleTimepoint = millis();
if(millis()-analogSampleTimepoint > 40U){ //every 40 milliseconds,read the analog value from the ADC
analogSampleTimepoint = millis();
analogBuffer[analogBufferIndex] = analogRead(TdsSensorPin); //read the analog value and store into the buffer
analogBufferIndex++;
if(analogBufferIndex == SCOUNT){
analogBufferIndex = 0;
}
}
static unsigned long printTimepoint = millis();
if(millis()-printTimepoint > 800U){
printTimepoint = millis();
for(copyIndex=0; copyIndex<SCOUNT; copyIndex++){
analogBufferTemp[copyIndex] = analogBuffer[copyIndex];
// read the analog value more stable by the median filtering algorithm, and convert to voltage value
averageVoltage = getMedianNum(analogBufferTemp,SCOUNT) * (float)VREF / 1024.0;
//temperature compensation formula: fFinalResult(25^C) = fFinalResult(current)/(1.0+0.02*(fTP-25.0));
float compensationCoefficient = 1.0+0.02*(temperature-25.0);
//temperature compensation
float compensationVoltage=averageVoltage/compensationCoefficient;
//convert voltage value to tds value
tdsValue=(133.42*compensationVoltage*compensationVoltage*compensationVoltage - 255.86*compensationVoltage*compensationVoltage + 857.39*compensationVoltage)*0.5;
Serial.print("voltage:");
Serial.print(averageVoltage,2);
Serial.print("V ");
Serial.print("TDS Value:");
Serial.print(tdsValue,0);
Serial.println("ppm");
}
}
}