This project consists on a temperature sensor using Arduino Uno microcontroller. There are 3 leds and a buzzer that turns on each one when its correspondig temperature range is reached. 

This project consists on a temperature sensor using Arduino Uno microcontroller and the LM35 transistor which is used to obtain the temperature. It also contains 3 leds (red, yellow and green), a buzzer and three 220 ohms resistors. The code is defined to receive the analog signal from the LM35 which is first converted to milivolts with the operation (transistorOutput*5000/1024). Then it is converted to Celsius. Since each 10 milivolts are equals to 1 Celsius the convertion is as follow: milivolts/10 = Celsius. Finally it's converted to Fahrenheit using the C -> F convertion. For temperatures less or equal than 59 Fahrenheit degrees the green led turns on, for temperatures less or equal than 100 Fahrenheit degrees the yellow led turns on and for temperatures greater than 100 Fahrenheit degrees the red led and the buzzer turn on. **DO NOT forget to use at least a 220 or 200 Ohm resistors for the leds or they will burn. The buzzer doesn't need any resistor since it can cause a small attenuation. 

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Kcosi 3 years, 8 months ago

Hi karli_12, Just thought that I would let you know that your breadboard view has some errors. 1) The LEDs are connected to ground with the anode pins 2) Both resistor pins for each LED are being bypassed by being in the same row. Basically the Arduino digital pins are connected directly to each LED without the current limiting resistor.

ameer_frit 3 years, 10 months ago

good