Help whit tmr1 on pic16f877a

[DonLuis]

Thanks for answering Archangel.

I don’t know the meaning of IMHO, but I appreciate your comment, now I am terrified to ask, do I have to do the hole code in assy?, I mean I been working on this project for over a year, you know, bumping my head around to get the hang of pbp, even blowing a couple pics and a few other components, I don’t main, there is no rush, just want to see it completed an working as I want to, I do not know anything about assembler, but yet I willing to learn if that is what it takes, on the meaning time I’ll take a look at Darrel’s interrupts.

[Archangel]

IMHO = In My Humble Opinion, good luck. Funny I don't even use cell phone . . .

do I have to do the hole code in assy?

No ooooooo

Here is a timer1 demo I made tonight for 16F690

@ __CONFIG _INTRC_OSC_NOCLKOUT & _WDT_ON & _PWRTE_ON & _MCLRE_OFF & _BOR_OFF & _FCMEN_OFF & _IESO_OFF 
INCLUDE "DT_INTS-14.bas"    ; Darrel Taylors instant interrupts
DEFINE OSC 4 

; * * * * * * * * * * * * * Setup Darrel's Instant Interrupts * * * * * * * *

ASM
INT_LIST  macro   ; IntSource,        Label,  Type, ResetFlag?
        INT_Handler    TMR1_INT,    _Flash,   ASM,  no
    endm
    INT_CREATE               ; Creates the interrupt processor
ENDASM

@   INT_ENABLE   TMR1_INT     ; enable external (INT) interrupts

; * * * * * * * * * * * * * Provide system variables to save return address' * * * *
;wsave   VAR BYTE    $20     SYSTEM      ; location for W if in bank0
wsave   VAR BYTE    $70     SYSTEM      ; alternate save location for W 
; * * * * * * * * * * * * SETUP DEBUG Parameters * * * * * * * * * * * * *
DEFINE DEBUG_MODE  0    ' Debug sending True serial data
DEFINE DEBUG_REG_PORTA  ' Debug Port = PortA as required by PICKIT2 serial Monitor
DEFINE DEBUG_BIT 0      ' Debug.bit = PortA.0
DEFINE DEBUG_BAUD 19200  ' Default baud rate = 9600
DEFINE DEBUGIN_REG PORTA' Debug Port = PortA as required by PICKIT2 serial Monitor 
DEFINE DEBUGIN_BIT 1    ' Debugin bit PortA.1
DEFINE DEBUGIN_BAUD 19200' Default baud rate = 9600
DEFINE DEBUGIN_MODE 0   ' Debugin receiving data true = 0 inverted = 1

; * * * * * * * * * * * * Setup Timer 1 registers  * * * * * * * * * * *

TMR1IF var PIR1.0       ' Explain to PBP which bit is the T1IF bit 
INTCON     = %11010000   ; GIE,PEIE,T0IE,INTE set RABIE,T0IF,INTF,RABIF cleared
PIR1       = %00000000
PIE1       = %00000001   ;      -,ADIE  ,RCIE ,TXIE ,SSPIE  ,CCP1IE,TMR2IE,TMR1IE
T1CON      = %01000101   ; T1GINV,TMR1GE,T1CKP,T1CKP,T1OSCEN,T1SYNC,TMR1CS,TMR1ON
CM2CON1    = %00000000


temp     var word
overFlow var word
overFlow      = 0
temp.highbyte = 0
temp.lowbyte  = 0

main:
   if temp.lowbyte >= 255 then
        temp.highbyte = temp.highbyte +1
        endif
   if temp >= 65535 then
      overFlow = overFlow + 1 ;track number of temp roll overs
   endif
debug " Temp Var High = ",#temp.highbyte," Temp Var Low = ",#Temp.Lowbyte," ",10

debug "OverFlow = ",#overFlow," temp var ",#temp,10



 goto main
; * * * * * * * * * * * * * End of Main Function * * * * * * * * * * * * *

@ INT_DISABLE  TMR1_INT
Flash:
        if TMR1IF  then       ; Flash is the ISR 
            temp = temp + 1 ; add 1 to timer roll over count
    endif
TMR1L = 0                   ; preload timer 0 with ? of 255 allows you to set counts until reset
TMR1H = 0
TMR1IF = 0                    ; Clear T1 Interrupt flag bit
 
@  INT_ENABLE  TMR1_INT
@  INT_RETURN

All this does is overflow the timer and display the results in PICKit2 USART display. It has Darrel's Instant Interrupts installed so you can pretty much copy paste, then use your registers as required

[aratti]

Hi Don, here my suggestion. If your max encoder count is not bigger of 65535 then you can feed your encoder pulses directly to timer1 input (pin 15 of you 16f877). Timer1 has to be set as a counter using "T1CON = %00000111" and then you have two ways to control your motor.

1) You poll the timer1 register TMR1H and TMR1L to see when the count reaches the desired value to stop the motor.
Or
2) you use DT interrupt (as already suggested) and you just load the count in Timer1 register (you have to load the complement : 65535-desired count) and wait for the overflow. In other words when the count is reached the value of the timer1 counter will be 65535 and adding one pulses it will overflow invocking the interrupt. In this routine (called ISR) you will stop your motor.

If your needed count is greater then 2^16 it it still possibile to use timer1 as a counter but in this case interrupt is mandatory.

Cheers

Al.

[DonLuis]

Hi guys:

Aratti; I already tried tmr1 interrupt on overflow, as you are suggesting, I explained that, on my post on July 21st, it’s just that seem to take too long to stop the motor and I get much more than I am barging for, sort of speech, also tried external interrupts on RB.0, and lastly polling from what I got much better results if you like to take a look to that post, I even included the code I used for each attempt.

Archangel; thank you for that, I already took a look to Darrel’s page and downloaded his .bas files and included, them on the PBP folder, (I feel relief now), but I’ll to try this first, since I got everything setup, and due to that I have fairly good results on polling, using the same encoder disc it measures twice de input because it is counting up on every negative and positive pulse, so just finished while ago a disc with 75 slot’s about half the other one, if still no good output then I try Darrel’s code, I’ll let you all know as soon as I get around it.

[aratti]

I already tried tmr1 interrupt on overflow, as you are suggesting,

I suggested timer1 overflow with a true interrupt (Darrel Taylor interrupt) your code didn't use any interrupt.

You can try to use this simple snippet which uses the timer1 as a counter, without interrupt and works pretty well.

False           con 0
True            con 1
Z0               Var Byte
Cnts            var word
Tape_Len        Var Word

Logic_1         var portXx  ' any available free input

Motor = False
Brake = False
TMR1H = 0
TMR1L = 0

Main_Loop:
If ????? goto  Load_Tape
If ????? goto Set_Tape_L
goto Main_loop

Set_tape_L:
Tape_Len = XXXXX ' encoder pulses derived from the tape lenght desired
return

Start_Motor:
Brake = False
Motor = True
Return

Stop_Motor:
Motor = false
Brake = True
Pause 200
Brake = False
T1CON.0 = False
Return


Load_Tape:
 Cnts = 0
TMR1H = 0
TMR1L = 0
T1CON.0 = true
Resume_Halt:
Lcdout $FE, 1,   "  Press Yy to stop  "
Lcdout $FE, $C0, "--------------------"
Lcdout $FE, $94, "Now Loading Tape ..."
Lcdout $FE, $D4, "Loaded: ",dec Cnts

Gosub Start_Motor

For Z0 = 0 To 100                               ' 100 millisecs delay
pause 1
if Logic_1 = True then Hw_Halt                  ' check if emergency stop is activated
Next Z0

Winding:                                                ' loading start here
Cnts.highbyte = TMR1H
 Cnts.lowbyte = TMR1L
         If Cnts => Tape_Len then 
         gosub Stop_Motor                           ' if count = lenght desired stop motor
         goto Main_Loop
         End If
   if Logic_1 = True then Hw_Halt                ' If emergency stop key pressed stop motor

Lcdout $FE, $D4, "Loaded: ",dec Cnts            ' display updated count
goto Winding

Hw_Halt:
gosub Stop_Motor
Emergency_menu:
1) if ????? then goto Resume_Halt
2) if ????? then goto Main_Loop
goto Hw_Halt

End

Naturally you need to complete the code replacing the parts with ?????? and Xx with reference to your hardware setup.

Cheers

Al.