The Atmega32 comes with a 10-bit, 8 channel inbuilt Ananlog to Digital Convertor (ADC). We will set it up and read temperature from LM35 and light with a simple (light dependent Resistor)LDR. So let's get started!
Basics
ADC Control and Status Register A (ACSRA):
| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
| ADEN | ADSC | ADATE | ADIF | ADIE | ADPS2 | ADPS1 | ADPS0 |
| 1 | 0 | 0 | 0 | 0 | 0 | 0 | 1 |
ADC Multiplexer Select (ADMUX)
| 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0 |
| REFS1 | REFS0 | ADLAR | MUX4 | MUX3 | MUX2 | MUX1 | MUX0 |
| 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |