Adafruit Temp Sensor Tutorial

If you re using a 5v arduino and connecting the sensor directly into an analog pin you can use these formulas to turn the 10 bit analog reading into a temperature.

Adafruit temp sensor tutorial.

Temp in c vout in mv 10. Additionally because the pct2075 allows the address pins to work in three states high low floating you can have 27 pct2075s on the same bus as. They work great with any microcontroller using standard i2c. Thermistors are made so that the resistance changes drastically with temperature so that it can be 100 ohms or more of change per degree.

To convert the voltage to temperature simply use the basic formula. Its very similar to the lm35 tmp35 celsius output and lm34 tmp34 farenheit output. These stats are for the temperature sensor in the adafruit shop the analog devices tmp36 40 to 150c. Technically all resistors are thermistors their resistance changes slightly with temperature but the change is usually very very small and difficult to measure.

Using a tmp36 temperature sensor with beaglebone black by simon monk. Measuring temperature with a beaglebone black. In this lesson you will learn how to use a ds18b20 with the raspberry pi to take temperature readings. A thermistor is a thermal resistor a resistor that changes its resistance with temperature.

Since the raspberry pi has no adc analog to digital converter it cannot directly use an analog temperature sensor like the tmp36 making the ds18b20 a good choice for temperature sensing. If you re using a lm35 or similar use line a in the image above and the formula. Reading temperatures to 0 1 degree precision. Compared to the lm75 however the 11 bit adc in the pct2075 provides more precise measurements when compared to the lm75 s 9 bit adc.

To use connect pin 1 left to power between 2 7 and 5 5v pin 3 right to ground and pin 2 to analog in on your microcontroller. Wide range low power temperature sensor outputs an analog voltage that is proportional to the ambient temperature. Voltage at pin in millivolts reading from adc 5000 1024 this formula converts the number 0 1023 from the adc into 0 5000mv 5v. The voltage out is 0v at 50 c and 1 75v at 125 c.

Tutorials and series to get you on your way. Temp in c vout in mv 500 10. The pct2075 by nxp is a pin compatible drop in replacement for a very common i2c temperature sensor the lm75.