1. PIC18F458 Analog-to-Digital
The PIC18F microcontroller includes:
10-bit A/D converter
5 to 15 channels of analog input
The converted output binary data is held by two SFR called ADRESL and ADRESH
Three control registers
ADCON0, ADCON1, and ADCON2
PIC 18F458 have 8 analog channel AN0 to AN7.
In 16bit ADRESL and ADRESH only 10 bits is used. We have option either upper 6bits or lower 6bits unused.
We have option ising VCC as a refrence or external voltage source connected in Vref input.

2. PIC18F458 Analog-to-Digital (A/D)

3. A/D Control Register0 (ADCON0)
Primary function of the ADCON0 register:
Select a channel for input analog signal
Start a conversion
Indicate the end of the conversion
Bit2 is set to start the conversion, and at the end of the conversion this bit is reset.

4. A/D Control Register0 (ADCON1)

5. A/D Control Register0 (ADCON1)

6. Example

7. Conversion Time

8. Step in pogramming the A/D using polling

9. Programming PIC18F ADC in Assembly

10. Interfacing of Temperature sensor

11. Interfacing of Temperature sensor

12. Interfacing of Temperature sensor