ADC_init

Description

This function initialises the ADC hardware and asynchronous ADC read subsystem. Hardware initialisation consists of configuring the pins which share analog and digital capabilities.

NOTE (1): This function only works for PIC's that have built-in ADC hardware. The function will accept all configurations in the table even though some configurations may not be supported by the target PIC.

NOTE (2): trying to read an analog value from a pin that is configured as a digital I/O pin will result in an aborted read and the value 0 will be returned

NOTE (3): trying to configure non-existant analog pins produces an undefined result (the 16F876 does not have AN7, AN6 or AN5). Trying to use a non-existant analog pin is as sensible as trying to use a non-existant digital I/O pin. This is a runtime error and is in the domain of the programmer not the compiler.

Definition

ADC_init(ubyte adc_port_config)

Library

LIB/adc_lib.bas

Usage

On entry:

adc_port_config defines the configuration of PORT A and PORT E pins

valid values are:

adc_port_config	AN7     RE2	AN6     RE1	AN5     RE0	AN4     RA5	AN3     RA3	AN2     RA2	AN1     RA1	AN0     RA0
0	A	A	A	A	A	A	A	A
1	A	A	A	A	Vref+	A	A	A
2	D	D	D	A	A	A	A	A
3	D	D	D	A	Vref+	A	A	A
4	D	D	D	D	A	D	A	A
5	D	D	D	D	Vref+	D	A	A
6	D	D	D	D	D	D	D	D
7	D	D	D	D	D	D	D	D
8	A	A	A	A	Vref+	Vref-	A	A
9	D	D	A	A	A	A	A	A
10	D	D	A	A	Vref+	A	A	A
11	D	D	A	A	Vref+	Vref-	A	A
12	D	D	D	A	Vref+	Vref-	A	A
13	D	D	D	D	Vref+	Vref+	A	A
14	D	D	D	D	D	D	D	A
15	D	D	D	D	Vref+	Vref+	D	A

see ADC configuration for a more detailed description

On exit:

There is no return value