You can use only the leds if you want, the lcd is optional. The Arduino sketch code is pretty simple even ... then on line 3 the pins where to connect the LCD display. On line 4 we use sensorPin array ...

I made this project because I wanted a way to automatically control the speed of a DC fan according to the temperature read by a LM35 sensor ... the output of the PWM pin on the Arduino board. I used ...