Subject:
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RE: Read A/D converter
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Newsgroups:
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lugnet.robotics.handyboard
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Date:
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Thu, 22 Oct 1998 14:21:26 GMT
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Original-From:
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Kevin B. Smith <kbsmith@eeSTOPSPAMMERS.byu.edu>
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Viewed:
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1631 times
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I didn't look that closely at your program but I have included a routine to
read the analog ports that I know works.
After assembling and loading the program, you make two c function calls:
powerup_ad(); and read_ad(i); where i is the analog port address you want to
read.
Best wishes,
Kevin Smith
Assistant Professor
Brigham Young University
***** Read_ad.asm *****************
BASE EQU $1000
ADCTL EQU $30
ADR4 EQU $34
OPTION EQU $39
ORG MAIN_START
subroutine_powerup_ad:
PSHX ;Preserve IX
LDX #BASE ;Points to register
BSET OPTION,X $80 ;ADPU = 1 to power up.
BCLR OPTION,X $40 ;CSEL = 0 to select E clock.
* ;need to wait for 100 us for
* A/D to warm up (but not done here).
PULX ;restore IX
RTS
subroutine_read_ad:
* ;Analog port should be in ACCB.
SEI ;Turn off System interrupts
PSHX ;Preserve IX
LDX #BASE ;Points to register
ANDB #%00000111 ;Set SCAN =0 & MULI = 0, ANx in low 3 bits(CC CB CA).
STAB ADCTL,X ;Store port select value
BRCLR ADCTL,X $80 * ;Wait for conversion to finish (i.e. CCF = 1)
LDAB ADR4,X ;Load result
CLRA
CLI ;Enable other interrupts
PULX ;restore IX
RTS
-----Original Message-----
From: HECTOR NORIEGA [mailto:110060.2126@compuserve.com]
Sent: Thursday, October 22, 1998 12:08 AM
To: Handyboard
Subject: Read A/D converter
"HI" , I am trying to read the A/D converter but the program gets "Hung-Up"
on the line ...
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Message is in Reply To:
 | | Read A/D converter
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| "HI" , I am trying to read the A/D converter but the program gets "Hung-Up" on the line "ANALOOP", the CCF bit never sets. Please give me a hint. Here is the Assembly code. /* MAGLEV.ASM, Magnetic Levitation by Hector Noriega, 28JUNE1998.*/ /*Handy (...) (26 years ago, 22-Oct-98, to lugnet.robotics.handyboard)
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