;
; adc.inc: a/d conversion routines for
;          tempo potentiometer sampling
;
; note: a/d converter is initialized in
;       startupinit.inc
;
; note: no acquisition delays are required
;       as the conversion is synchronized
;       with timer 2
;
; author: Marko Kanala, raato ]a t[ mulletronic.com
;
; LICENSE
; Creative Commons Attribution-NonCommercial-ShareALike 2.5
;
; You are free:
;
; * to copy, distribute, display, and perform the work
; * to make derivative works
;
; Under the following conditions:
;	
; 1. Attribution. You must attribute the work in the manner specified by the 
;    author or licensor.
; 2. Noncommercial. You may not use this work for commercial purposes.
; 3. Share Alike. If you alter, transform, or build upon this work, you may 
;    distribute the resulting work only under a license identical to this one.
;
; * For any reuse or distribution, you must make clear to others the license 
;   terms of this work.
; * Any of these conditions can be waived if you get permission from the 
;   copyright holder.
;
; Your fair use and other rights are in no way affected by the above.
;
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; See full license at http://creativecommons.org/licenses/by-nc-sa/2.5/legalcode
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; Copyright: Marko Kanala (raato@mulletronic.com).
;

; (re)starts the a/d conversion 
ad_start:
	movlw	do_ad_every_timer2
	movwf	ad_delay
	bsf		ADCON0, GO
	return

; called on a/d converter interrupt
;  occurred - reads the current value
;  and assigns the tempo with the value
ad_irq:
	movf	ADRESH, W	; read a/d value
	; set tempo
	;  0   == 30 bpm
	;  255 == 285 bpm
	cpfseq	tempo		; tempo changed ?
	bra		ad_tempo_changed
	return

ad_tempo_changed:
	movwf	tempo
	SETEVENT	EVENT_TEMPOCHANGE
	return

;
; called on timer2 interrupt
; see irq_lopri.inc
;
ad_timer2:
	decfsz	ad_delay
	return
	call	ad_start
	return

ad_start