From stick to strip

5. The serial plotter

We will now amend the previous sketch in order to plot temperature and heat index on the computer offline:


#include "DHT.h"
#define DHTPIN 2     // what digital pin we're connected to

#define DHTTYPE DHT11   // DHT 11
DHT dht(DHTPIN, DHTTYPE);

void setup() {
  Serial.begin(9600);
  Serial.println("DHTxx test!");
  dht.begin();
}

void loop() {
  // Wait a few seconds between measurements.
  delay(2000);

  // Sensor readings may also be up to 2 seconds 'old' (its a very slow sensor)
  // Read temperature as Celsius (the default)
  float t = dht.readTemperature();

  // Check if any reads failed and exit early (to try again).
  if (isnan(t)) {
    return;
  }
  Serial.println(t);

}

Now open Tools > Serial Plotter and see the temperature plot of the real-time sensor data. This feature is very handy when debugging sensors with Arduino.

You can also plot more than one variables at a time, by seperating them with a

Serial.print(" ");
.