Instant Int and encoder (Elect. Gearing)

[boroko]

Hi all,

I have been working on this for too long and I'm starting to chase my tail.

I'm to the point that I can remember the post numbers, but I'm still overlooking something.

The purpose is this:
1) Read Encoder #1 to measure direction and distance of a linear movement.
2) If travel is +, do nothing
3) if travel is -, feed pulses to a servo driver to move a motor (feed material at same rate as linear retract).
4) there a couple of lines I left in for adding manual over-ride.
5) testing on a 877 with a X-1 board but the target can be anything.

Thanks for taking a look.
Bo

' 1)Quadrature encoder reading direction and speed of mechanical slide.
' 2) Motor (servo) driven in ONE direction of slide movement,
' not driven for other direction. Pulse & Direction drive.
' 3) Overide switches to drive servo either direction manually.
'
A_INPUT VAR PORTB.4 'encoder A input
B_INPUT VAR PORTB.5 'encoder B input
F_Sw var PORTB.6 'Foward switch input
R_sw var PORTB.7 'Reverse Sw input
P_out var PORTA.0 'Pulse out to motor
D_out var PORTA.1 'level out for direction
'only for manual Sw
' drive. Implement Ltr.
LED1 var PORTA.5 'heartbeat for INT
RdEnc1 VAR BIT
RdEnc2 VAR BIT
COUNTER VAR WORD

TRISA = %00000000
TRISB = %11111111
TRISD = %00000000
OPTION_REG.7 = 0 'enable POTRB pull-ups

INCLUDE "DT_INTS-14.bas" 'Base Inturrupt program
include "ReEnterPBP.pbp" 'allow PBP int

ASM
INT_LIST macro ;IntSource, Label, Type, ResetFlag?
INT_Handler RBC_INT, _MotorDrive, PBP, yes
INT_Handler INT_INT, _ToggleLED1, PBP, yes
endm

INT_ENABLE RBC_INT ;enable RB change int
INT_ENABLE INT_INT ; enable external (INT) interrupts
ENDASM

Start
RdEnc2 = A_INPUT & ~ RdEnc1 'EVERY POSITIVE GOWING EDGE OF A_INPUT
RdEnc1 = A_INPUT 'GIVES A PULSE OF ONE PROGRAM CYCLE

IF RdEnc2 = 1 AND B_INPUT = 1 Then 'Encoder TURNS CW: UP
COUNTER = 1
EndIF

IF RdEnc2 = 1 AND B_INPUT = 0 Then 'Encoder TURNS CCW: DN
COUNTER = 0
EndIF

counter = portb & %00000011 'for troubleshooting: strip i/p.
PORTD = counter 'for troubleshooting: to see i/p.

goto start

'+++++++++++++++++
'Motor Drive Pulse Out inturrupt handler
'++++++++++++++++++
MotorDrive:
if counter = 1 then
pulsout P_out,100
endif
@ INT_RETURN
'---[INT - interrupt handler]---------------------------------------------------
ToggleLED1:
TOGGLE LED1
@ INT_RETURN
end

[skimask]

pulsout P_out,100

pulsout is a 'blocking' statement, a 'synchronous' statement.
In other words, if you're trying to do something at the same time as you're trying to 'pulsout', that something might not get done until the pulsout is done doing what it has to do.

[Darrel Taylor]

Pay no attention to the man behind the curtain. (or was that a mask)

With DT_INTS, nothing is "blocking" except the interrupt handlers themselves.

And if the conditions that generated the interrupt are not cleared, the handler will continue "blocking" everything.

In your MotorDrive routine (RBC_INT handler), you MUST read PORTB to end the mismatch condition.

Additionally, the statements to read the encoder should be in that handler too.

Here's a snippet from SteveB for 2 rotary encoders, may give you some ideas.
http://www.picbasic.co.uk/forum/showthread.php?p=25396

hth,

[skimask]

Pay no attention to the man behind the curtain. (or was that a mask)
With DT_INTS, nothing is "blocking" except the interrupt handlers themselves.

DOH!!! no kidding...

[boroko]

Thanks for the replys Darrell and Skimask.
I so hate asking for help for something thats likely to be an oversight on my part. I don't ever want to abuse the list's willingness to help.

I'm going through your suggestions and the first thing that I don't understand in http://www.picbasic.co.uk/forum/showthread.php?p=25396 is this:
================
ASM
INT_LIST macro ; IntSource, Label, Type, ResetFlag?
INT_Handler INT_INT, _Rot_Encoder, PBP, yes
endm
INT_CREATE ; Creates the interrupt processor
ENDASM

@ INT_ENABLE RBC_INT ;RB Port Change Interrupt
==============

My understanding was that the INT_INT was for RB0 (external Int) only and that RBC_INT was for the "change on RB 4-7".
I'm going to test and try to answer my own question, but I thought it should be answered in print. I know I have spun in small circles after looking for stuff like this.

Bo

[Darrel Taylor]

My understanding was that the INT_INT was for RB0 (external Int) only and that RBC_INT was for the "change on RB 4-7".

Correct!

Steve had found that bug later in the thread. I forgot to mention it.

It should be RBC_INT.
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