TMP36 Analog Temperature Sensor

TMP36 Analog Temperature Sensor

TMP 36

• Analog temperature sensor
• Measures environment temperature and returns a voltage
• Output voltage is linearly proportional to temperature
  • What does this mean?

TMP 36

TMP 36 Datasheet

• What are the most important elements we should be looking for?
• Datasheet

Conversion

• 10 mV / deg Celsius with a 500 mV offset (since voltage is 500 mv at 0 deg Celsius)
• Try this: if Vout is 1.2V, what is the temperature in Celsius? in Fahrenheit?
• Remember:
  • T(fahr) = T(cel) * (9/5) + 32
  • T(cel) = (T(fahr) - 32 ) * (5/9)

Important: C++ int and float

• Division with ints in C++ truncates decimals

int x = 3;
int y = 6;
float result = x / y; // 0 since 3/6 is truncated` 

• Instead, make sure to cast (convert) one of the int values to be a float

int x = 3;
int y = 6;
float result = (float) x / y;

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TMP36 Wiring

• Note that is BOTTOM VIEW

Exercise Wiring

Exercise

• Connect a TMP36 and output the current temperature to the serial monitor
• Consider what type of input is this signal? How will this value be read by Photon 2?

Credit

• Analog datasheet
• Sparkfun
• Images created with Fritzing