CIRC15 uses code that will work for both the Metro and the Metro Express. You'll need to make a tiny modification to it to get it working with the Metro you own. (If you're not sure what board you have, click here!).
/*
* CIRC15: Digital Thermometer
* Experimenter's Guide for Metro (and Metro Express!)
* by Brent Rubell for Adafruit Industries ~ Support Open Source, buy adafruit!
*/
// If you're using a METRO EXPRESS, change this value to 3.333
#define ANALOGREFVOLTAGE 5.000
// include the lcd library code:
#include <LiquidCrystal.h>
// initialize the library with the numbers of the interface pins
LiquidCrystal lcd(7, 8, 9, 10, 11, 12);
// TMP36 Pin
int temperaturePin = 0;
void setup() {
Serial.begin(9600);
// set up the LCD's number of columns and rows:
lcd.begin(16, 2);
}
void loop() {
float temperature = 0;
temperature = getVoltage(temperaturePin);
/* Output: Degrees C */
temperature = (temperature - .5) * 100;
/* Output: Degrees F */
// temperature = (((temperature - .5) * 100)*1.8) + 32;
/* Output: Voltage */
// temperature = (temperature - .5) * 100; d
// Write temperature to the LCD
lcd.print("Temp: ");
lcd.setCursor(6,0);
lcd.print(temperature);
lcd.setCursor(11,0);
lcd.print("*C");
// Wait 1s
delay(1000);
// Refresh the LCD
lcd.clear();
}
float getVoltage(int pin) {
return(float(analogRead(pin))* float(ANALOGREFVOLTAGE/1023.000));
}
Try twisting the potentiometer. If that doesn't work, re-check your wiring.
Make sure the pins of the LCD are flush with the breadboard. If that doesn't work, re-upload the sketch from Arduino.
The included code has a line that uses the serial monitor. Pop open the serial monitor and check the number in there against what you think the current temperature is. If the number seems off, double check wiring to Analog Pin A0.
The character LCD has a lot of wires and it's hard to keep track. We have a great guide that takes you step-by-step. Check it out!
