|
Ken,
Darrel's site must have been down for what evere reason. It seems to work now.
http://www.PBPgroup.com/
ASM instuctions are normally in the devices data sheet. But... Please do not take this the wrong way. If you are having trouble with Basic I doubt it ASM will do much good.
I like remto's sugesstion about blinky. Give that a shot.
Dave
Always wear safety glasses while programming.
|
Ken, I highly recommend taking Dave's advise. You need a better understanding of what makes a PIC tick (hint, read the free book I linked to). When you have that under your belt, then the coding is the really easy part. It doesn't matter whether you use C, BASIC (PBP or some other variant) or ASM - the situation is the same.Originally Posted by mackrackit
|
12f683 servo pass through
Here is some code that will measure an RC receiver pulse width coming in on GPIO.2, perform a little math on the value, and put out the wave form out on GPIO.1, using DT Interrupts.
It's on a little 12F683 and was written for 8mhz internal. Looks pretty good on the scope. I need to test it on a motor controller though. But time for bed.....
Code:<html> <head></head> <body><!--StartFragment--><pre><code><font color="#000080"><i> </i></font><b>DEFINE </b>OSC 8 <b>INCLUDE </b><font color="#FF0000">"DT_INTS-14.bas"</font><font color="#000080"><i>;interrupt routines </i></font><b>INCLUDE </b><font color="#FF0000">"sub16.inc" </font><font color="#000080"><i>; subtract 16 bit macro </i></font><b>DEFINE </b>DEBUG_REG GPIO <b>DEFINE </b>DEBUG_BIT 0 <b>DEFINE </b>DEBUGIN_BIT 1 <b>DEFINE </b>DEBUG_BAUD 38400 <b>DEFINE </b>DEBUG_MODE 0 INTCON = %10101000 <font color="#000080"><i>' </i></font>OSCCON = %01110000 <font color="#000080"><i>'set for 8mhz internal </i></font>CMCON0 = 7 <font color="#000080"><i>'TURN COMPARITORS OFF </i></font>ANSEL = %00000000 <font color="#000080"><i>'Set A/D OFF </i></font>ADCON0 = %00000000 <font color="#000080"><i>'Analog converter OFF </i></font>TRISIO = %010100 <font color="#000080"><i>'Set GSIO 4 and 2 to INPUT, others to OUTPUT </i></font>OPTION_REG = %11000010 T1CON = %00110001 T2CON = %01001110 CCP1CON = %00000101 risetime <b>VAR WORD </b><font color="#000080"><i>;used for pulse width measure start of pw </i></font>falltime <b>VAR WORD </b><font color="#000080"><i>;time at end of pulse width </i></font>falltime_l <b>VAR </b>falltime.Byte0 falltime_h <b>VAR </b>falltime.Byte1 risetime_l <b>VAR </b>risetime.Byte0 risetime_h <b>VAR </b>risetime.Byte1 pulsewidth <b>VAR WORD </b>pulsewidth_l <b>VAR </b>pulsewidth.Byte0 pulsewidth_h <b>VAR </b>pulsewidth.Byte1 ServoOut <b>VAR </b>GPIO.1 ServoOut = 0 pulse <b>VAR BYTE </b>TMR0 = 0 pulse = 255 bittest <b>VAR BIT ASM </b><font color="#008000">INT_LIST macro </font><font color="#000080"><i>; IntSource, Label, Type, ResetFlag? </i></font><font color="#008000">INT_Handler TMR0_INT, PulseOut, ASM, yes INT_Handler TMR2_INT, period, ASM, yes INT_Handler CCP1_INT, PWMeasure, ASM, yes endm INT_CREATE </font><font color="#000080"><i>; Creates the interrupt processor </i></font><font color="#008000">INT_ENABLE TMR0_INT </font><font color="#000080"><i>; Enable pulseout interrupts </i></font><font color="#008000">INT_ENABLE TMR2_INT </font><font color="#000080"><i>; enable period interrupt (20ms) </i></font><font color="#008000">INT_ENABLE CCP1_INT </font><font color="#000080"><i>; enable interrupt to increment pulse width (test) </i></font><b>ENDASM PAUSE </b>200 Main: <b>PAUSE </b>20 <font color="#000080"><i>;debug dec pulsewidth," ",10,13 </i></font>pulse = ((pulsewidth * 8)/10)-167 <font color="#000080"><i>;scale to fit into a byte </i></font>pulse = 255 - pulse <font color="#000080"><i>;reverse the stick </i></font><b>GOTO </b>Main <font color="#000080"><i>'---[TMR0_INT - interrupt handler]------------------------------------------ </i></font><b>ASM </b><font color="#008000">PulseOut btfsc _bittest </font><font color="#000080"><i>;test status of bittest bit </i></font><font color="#008000">goto $+7 </font><font color="#000080"><i>;if high skip 7 lines </i></font><font color="#008000">bcf INTCON,5 </font><font color="#000080"><i>;stop timer </i></font><font color="#008000">movf _pulse,w </font><font color="#000080"><i>;load TMR0 with value of pulse variable </i></font><font color="#008000">movwf TMR0 bsf _bittest </font><font color="#000080"><i>;set bittest bit, indicating we are on second half </i></font><font color="#008000">bsf INTCON,5 </font><font color="#000080"><i>;start timer again for second interrupt </i></font><font color="#008000">goto $+3 </font><font color="#000080"><i>;skip to return from interrupt </i></font><font color="#008000">bcf INTCON,5 </font><font color="#000080"><i>;stop timer </i></font><font color="#008000">bcf _ServoOut </font><font color="#000080"><i>;bring ServoOut pin low for end of pulse width </i></font><font color="#008000">INT_RETURN </font><b>ENDASM </b><font color="#000080"><i>'---[TMR2_INT - interrupt handler]------------------------------------------ </i></font><b>ASM </b><font color="#008000">period movlw d'72' </font><font color="#000080"><i>;fine tune timer2 period </i></font><font color="#008000">movwf TMR2 bcf INTCON,2 </font><font color="#000080"><i>;clear timer flag if set </i></font><font color="#008000">movlw d'17' </font><font color="#000080"><i>;set timer0 first 1ms time base </i></font><font color="#008000">movwf TMR0 bsf INTCON,5 </font><font color="#000080"><i>;enable timer0 interrupt </i></font><font color="#008000">bsf _ServoOut </font><font color="#000080"><i>;set ServoOut pin high (begin pulse width) </i></font><font color="#008000">bcf _bittest INT_RETURN </font><b>ENDASM </b><font color="#000080"><i>'---[CCP1_INT - interrupt handler]------------------------------------------ </i></font><b>ASM </b><font color="#008000">PWMeasure BTFSS CCP1CON, CCP1M0 </font><font color="#000080"><i>; Check for falling edge watch </i></font><font color="#008000">GOTO FALL_EDGE </font><font color="#000080"><i>; Go pick up the falling edge </i></font><font color="#008000">MOVF CCPR1L,W </font><font color="#000080"><i>; else store leading edge value </i></font><font color="#008000">MOVWF _risetime_l </font><font color="#000080"><i>; into 16 bit word risetime </i></font><font color="#008000">MOVF CCPR1H,W MOVWF _risetime_h BCF CCP1CON, CCP1M0 </font><font color="#000080"><i>; Now capture the trailing edge </i></font><font color="#008000">GOTO ISR_2 </font><font color="#000080"><i>; Exit the interrupt service routine </i></font><font color="#008000">FALL_EDGE: BSF CCP1CON, CCP1M0 </font><font color="#000080"><i>; Re-set for trailing edge capture </i></font><font color="#008000">MOVF CCPR1L,W </font><font color="#000080"><i>; Store the captured value into </i></font><font color="#008000">MOVWF _falltime_l </font><font color="#000080"><i>; falltime_l and ... </i></font><font color="#008000">MOVF CCPR1H,W MOVWF _falltime_h </font><font color="#000080"><i>; ... falltime_h ; ; 16 bit subtract ; falltime = falltime - risetime ; </i></font><font color="#008000">SUB16 _falltime, _risetime </font><font color="#000080"><i>;do 16 bit subtraction to find width </i></font><font color="#008000">movf _falltime_l,w movwf _pulsewidth_l movf _falltime_h,w movwf _pulsewidth_h ISR_2 INT_RETURN </font><b>ENDASM </b></code></pre><!--EndFragment--></body> </html>
|
Up to page 19 in DS33014K
At last I am getting the correct reference materials.
DS33014K is telling me about MPASM Assembler, Library and Linker.
I have ordered from Belgrade "PIC Microcontrollers". It is being shipped by air. That alone is pretty amazing. Just a little paperback book.
I have also found an online book at:
http://www.mikroe.com/en/books/picmcubook/ch0/
It may be the same book only on line. I am old fashioned. I like to read from paper.
I have plenty of studying to do. Thank you again and again.
Ken
|
mackrackit: where do I get your .INC
I copied your code snip from POST #73 at 3:02 on the 28th of January.
I noticed in the .asm code that it wanted to:
INCLUDE "MACKRA~1.MAC"
There is no such file in my computer. Do I need a copy? May I have one?
Also the compiler complained that:
Error 118: "Overwriting previous address contents (2007)
Page 157 of DS33014K says that Error 118 occurred because "Code was previously generated for this address" I assume it is talking about address (2007). I do not see where in the .asm code this is happening. I do not even know what to look for.
Ken
|
I need to send one pulse every 20ms
Mackrackit,
From what I understand your code will do a PWM every time TMR0 overflows.
What I need to do is make this overflow happen every 20ms. That is 50 pulses per second. We have a 4 meg oscillator. If I were designing this counter I think I would have it set to 20,000 each time it overflows. I gather from page 74 of the Data Sheet that this is not possible. The biggest prescaler is 256.
How about a routine that counts these interrupts until 1/50 of a second has elapsed then calls PWM? I would have it send one pulse out pin 1 with the duty as defined by "duty". It would look like
PWM 1,duty,1
I have found a section on Timers in a book called Running Small Motors with PIC Microcontrollers that has an example of MicroEngineering Labs code that makes an eight digit LCD display the time in hours, minutes and seconds. I think this code must do something like I need.
Ken
|
You want 20,000 counts before it overflows. Setting the prescaler to 1:256, you will need 20,000/256 counts = 78. The counter rolls over (overflows and sets T0IF) when it reaches 255, so if you pre-load it with 255-78 = 177, then it will overflow approximately every 20mS.
|
The code in post #73 will toggle a LED when TMRO overflows. The LED on PORTD.7 will gradually become brighter then turn off and start over again.
This was just an example of an interrupt working with something else going on.
You do have to be careful with this as things will sometimes not work as expected. Like they say, the machine will do what it is told, not what you want
This is the same code as in post #73 with some modifications to demonstrate a "pitfall".
The START loop still has PORTD.7 PWMing the LED with PORTD.0 added to be toggled.
Inside of the interrupt loop the same PWM that is on PORTD.7 is now on PORTD.6.
What do you think will happen?
What does happen?
Code:'16F887 INT RUPT '44 PIN DEMO BOARD @ __config _CONFIG1, _INTRC_OSC_NOCLKOUT & _WDT_ON & _MCLRE_OFF & _LVP_OFF & _CP_OFF INTCON.5 = 1 'ENABLE TMR0 DATA SHEET SECTION 14.3.2 OSCCON = %01110000 '8 Mhz OPTION_REG = %10000111 ' 1:256 PRESCALE ON INTERRUPT GOTO TLOOP CNT VAR BYTE D VAR BYTE D = 0 HIGH PORTD.0 PAUSE 500 START: FOR CNT = 0 TO 150 PWM PORTD.7,D,100 D = D + 2 NEXT CNT TOGGLE PORTD.0 PAUSE 100 GOTO START DISABLE TLOOP: INTCON.2=0 ' DATA SHEET SECTION 14.3.2 TOGGLE PORTD.4 FOR CNT = 0 TO 150 PWM PORTD.6,D,100 D = D + 2 NEXT CNT RESUME ENABLE
Dave
Always wear safety glasses while programming.
|
Code in #73 WORKS!!
Just like you said it would.
Now on to your next one. It compiles and works also. I see what it does. I need to figure out how.
Thank you!!
|
Looks like you have the code named MACKRACKIT?
The *.MAC file is the macro file generated by PBP. It will be in your project directory. The name is chopped to the 8.1? standards.
Looks like you are setting the configs in the *.inc file. I have them in the code. Just comment that line out and it should be OK.Also the compiler complained that:
Error 118: "Overwriting previous address contents (2007)
Page 157 of DS33014K says that Error 118 occurred because "Code was previously generated for this address" I assume it is talking about address (2007). I do not see where in the .asm code this is happening. I do not even know what to look for.
Ken
Dave
Always wear safety glasses while programming.
Members who have read this thread : 0You do not have permission to view the list of names.
Posting Permissions
Bookmarks