Lowest and highest values from this code

Projects Programming
1 
void setup() {
  Serial.begin(115200);
}
void loop() {
  int val;
  val = analogRead(A0);
  Serial.println(val);
  delay(100);
}

is it possible to change this code where you see the lowest and highest values?

thanks in advandce

2

Yes

Add two variables, e.g. maxVal and minVal; they either need to be global (declared before setup()) or static in loop().

After reading the analog input as you do now, compare val with those two variables and update them when needed.

3

im new with this so , im still learning :rofl:

can you show the code

4 
int minVal = 1023;
int maxVal = 0;

void setup()
{
  ...
  ...
}

void loop()
{
  int val;
  val = analogRead(A0);
  // update minVal if val is lower than current minVal
  if(val < minVal)
  {
    minVal = val;
  }
}

You can puzzle on maxVal.

5

Hello ronnys

Welcome to the world's best Arduino forum ever.

Consider:

enum analogValues {Current, Min, Max};
uint16_t analogValue[] {0, 1023, 0};
constexpr uint8_t AnalogPin {A0}; 
void setup()
{
  Serial.begin(115200);
  Serial.println("get ready");
}
void loop()
{
  analogValue[Current] = analogRead(AnalogPin);
  if (analogValue[Current] < analogValue[Min]) analogValue[Min] = analogValue[Current], Serial.print("value min = "), Serial.println(analogValue[Min]);
  if (analogValue[Current] > analogValue[Max]) analogValue[Max] = analogValue[Current], Serial.print("value max = "), Serial.println(analogValue[Max]);
}

Have a nice day and enjoy coding in C++.

7

Code seems to work very well. Any chance you can elaborate for those of us who are new? What's the purpose of enum, constexpr, and the square brackets in the loop?

8

Hello nuk3man

These are instructions from the C++ toolbox.

Take a look at them to acquire the knowledge:

https://www.learncpp.com/

9 
const byte moistureSensorPowerPin = 19;

enum analogValues {Current, Min, Max};
uint16_t analogValue[] {0, 1023, 0};
constexpr uint8_t AnalogPin {A5}; 
void setup()
{
  Serial.begin(115200);
  Serial.println("get ready");
  pinMode(moistureSensorPowerPin, OUTPUT);
  digitalWrite(moistureSensorPowerPin, HIGH);
}
void loop()
{
  analogValue[Current] = analogRead(AnalogPin);
  if (analogValue[Current] < analogValue[Min]) analogValue[Min] = analogValue[Current], Serial.print("value min = "), Serial.println(analogValue[Min]);
  if (analogValue[Current] > analogValue[Max]) analogValue[Max] = analogValue[Current], Serial.print("value max = "), Serial.println(analogValue[Max]);
}

thanks for te Code , this works for me

10 
void setup() {
  Serial.begin(9600); // start serial comms
}

void loop() {
  findhighlow();
}

void findhighlow() {
  // find highest and lowest and when they occurred in the count
  // only Serial.print()s when LOWEST or HIGHEST changes

  unsigned long reading = 0; // new reading
  unsigned long highest = 0; // highest value (set to lowest possible value)
  unsigned long lowest  = 1023;// lowest value (set highest possible value)
  unsigned long count = 0; // running count for when min/max occurrs
  unsigned long readCountHighest = 0; // the reading count when the highest value occurred
  unsigned long readCountLowest = 0; // the reading count when the lowest value occurred
  boolean newCurrentHighLow = 0; // signals a new high or low

  // randomSeed(analogRead(A0));

  while (1) {
    reading = analogRead(A0); // random reading
    count++; // store loop count

    if (reading > highest)
    {
      highest = reading;
      newCurrentHighLow = true;
      readCountHighest = count;
    }

    if (reading < lowest)
    {
      lowest = reading;
      newCurrentHighLow = true;
      readCountLowest = count;
    }

    if (newCurrentHighLow) // only print when a new low or high ocurrs
    {
      newCurrentHighLow = false;
      Serial.print("(NEW value ");
      Serial.print(reading);
      Serial.print(" at count ");
      Serial.print(count);
      Serial.print(")");

      Serial.print(" (LOWEST value ");
      Serial.print(lowest);
      Serial.print(" at count ");
      Serial.print(readCountLowest);
      Serial.print(")");

      Serial.print(" (HIGHEST value ");
      Serial.print(highest);
      Serial.print(" at count ");
      Serial.print(readCountHighest);
      Serial.println(")");
    }
  }
}
11

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