Hola:
Bueno, porqué no consultas la ayuda? hay un ejemplo listo para probar, te lo pego tal cual está en la ayuda de Protón:
ADIN
Syntax
Variable = ADIN channel number
Overview
Read the value from the on-board Analogue to Digital Converter.
Operators
Variable - a user defined variable of type bit, byte, byte_array, word, word_array, dword, or float.
Channel number - a constant, variable, or expression.
Example
'Read the value from channel 0 of the ADC and place in variable VAR1.
DECLARE ADIN_RES 10 ' 10-bit result required
DECLARE ADIN_TAD FRC ' RC OSC chosen
DECLARE ADIN_STIME 50 ' Allow 50us sample time
DIM VAR1 as WORD
TRISA = %00000001 ' Configure AN0 (PORTA.0) as an input
ADCON1 = %10000000 ' Set analogue input on PORTA.0
VAR1 = ADIN 0 ' Place the conversion into variable VAR1
Declares
There are three declare directives for use with ADIn. These are: -
DECLARE ADIN_RES 8 , 10 , or 12
Sets the number of bits in the result. If this declare is not used, then the default is the resolution of the PICmicro type used. For example, the 16F87X range will result in a resolution of 10-bits, along with the 16-bit core devices, while the standard PICmicro types will produce an 8-bit result. Using the above declare allows an 8-bit result to be obtained from the 10-bit PICmicro types, but NOT 10-bits from the 8-bit types.
DECLARE ADIN_TAD 2_FOSC , 8_FOSC , 32_FOSC , or FRC.
Sets the ADC's clock source. All compatible PICmicros have four options for the clock source used by the ADC. 2_FOSC, 8_FOSC, and 32_FOSC, are ratios of the external oscillator, while FRC is the PICmicro's internal RC oscillator. Instead of using the predefined names for the clock source, values from 0 to 3 may be used. These reflect the settings of bits 0-1 in register ADCON0.
Care must be used when issuing this declare, as the wrong type of clock source may result in poor resolution, or no conversion at all. If in doubt use FRC which will produce a slight reduction in resolution and conversion speed, but is guaranteed to work first time, every time. FRC is the default setting if the declare is not issued in the BASIC listing.
DECLARE ADIN_STIME 0 to 65535 microseconds (us).
Allows the internal capacitors to fully charge before a sample is taken. This may be a value from 0 to 65535 microseconds (us). A value too small may result in a reduction of resolution. While too large a value will result in poor conversion speeds without any extra resolution being attained.
A typical value for ADIN_STIME is 50 to 100. This allows adequate charge time without loosing too much conversion speed. But experimentation will produce the right value for your particular requirement. The default value if the declare is not used in the BASIC listing is 50.
Notes
Before the ADIn command may be used, the appropriate TRIS register must be manipulated to set the desired pin to an input. Also, the ADCON1 register must be set according to which pin is required as an analogue input, and in some cases, to configure the format of the conversion's result. See the numerous Microchip datasheets for more information on these registers and how to set them up correctly for the specific device used.
If multiple conversions are being implemented, then a small delay should be used after the ADIn command. This allows the ADC's internal capacitors to discharge fully: -
Again:
VAR1 = ADIN 3 ' Place the conversion into variable VAR1
DELAYUS 1 ' Wait for 1us
GOTO Again ' Read the ADC forever
Revisa siempre la ayuda antes de consultar algo, está todo bien detallado y tiene varios ejemplos como el de este caso.
