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Who sees my stupid mistake?
Hello,
After not having used picbasic for a couple of years, I decided to create some code to produce MIDI information.
The intended use is to have five buttons to control a DAW.
The code compiles without a problem, but I don't get any MIDI (31.250 Baud) output. Xtal = 20 MHz, PIC = 16F628.
I think I made an obvious mistake, but I don't see what it could be...
Code:
'* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
'* MIDI Remote for Reaper 20 MHz resonator (HS)
'* PIC16F628 Watchdog timer OFF
'* PORTA.0 = Output
'* PORTB.0 = Rewind
'* PORTB.1 = FastFwd.
'* PORTB.2 = Stop
'* PORTB.3 = Play
'* PORTB.4 = Record
'* PORTB.5 = Switch between: Stop / Stop + Save
'* Version 1.0
'* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
TRISB= %00111111 ' PORTB.6/7=Output 0..5=Input
CMCON = 7 ' Digitale mode
DEFINE OSC 20 ' 20 MHZ OSC.
Progstart:
if PORTB.0 = 1 then
Serout2 PORTB.7, 16384+12, [144, 44, 127] ' Rewind
endif
if PORTB.1 = 1 then
Serout2 PORTB.7, 16384+12, [144, 46, 127] ' Fast Fwd.
endif
if PORTB.2 = 1 then
if PORTB.5 = 0 then ' Normal STOP mode
Serout2 PORTB.7, 16384+12, [144, 48, 127] ' Stop
else
Serout2 PORTB.7, 16384+12, [144, 54, 127] ' Stop + Save
endif
endif
if PORTB.3 = 1 then
Serout2 PORTB.7, 16384+3313, [144, 50, 127] ' Play
endif
if PORTB.4 = 1 then
Serout2 PORTB.7, 16384+3313, [144, 52, 127] ' Record
endif
Debounce:
Pause 20 ' ? shorter ?
If (PORTB.0=1) or (PORTB.1=1) or (PORTB.2=1) or (PORTB.3=1) or (PORTB.4=1) then
goto Debounce ' Button still pressed?
endif
Goto Progstart
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Re: Who sees my stupid mistake?
I forgot to mention that there are resistors to ground (to keep the input 'low' when no button is pressed) and that the buttons switch to the +5 Volts.
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Re: Who sees my stupid mistake?
16384+12 seems correct for (inverted) 31250 but should it BE inverted and why 16384+3313? (I don't know MIDI...)
Can you do a standard baudrate like 9600 and verify that data is coming out by using a terminal program?
The 16F628 does have UART so HSEROUT will work with it. I'd try that but you might need to invert the signal externally.
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Re: Who sees my stupid mistake?
The 16384+12 is correct, I have used that before.
The calculation is: (1.000.000/Baudrate) - 20 , so 1.000.000 / 31250 = 32 -20 = 12.
For inverted output set bit 14, = 16384.
But even with a different baudrate I don't get any output.
I did a quick test to trace the problem.
With this code, nothing 'toggles':
Code:
Progstart:
if PORTB.0 = 1 then
Toggle PORTB.6
endif
Debounce:
Pause 20 ' ? shorter ?
If PORTB.0=1 then
goto Debounce ' Button still pressed?
endif
Goto Progstart
So I suspect the problem is in the line (and similar lines)
Although I don't see what could be wrong with this...
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Re: Who sees my stupid mistake?
If I don't touch programming for a while, I start with blinking a LED to make sure I have the basics working right (config, circuit, programming, etc).
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Re: Who sees my stupid mistake?
Quote:
Originally Posted by
RuudNL
...
If PORTB.0=1
...
You're assuming it can read port B properly.
I'd start even easier, just blink a LED, nothing else, then build from that.
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Re: Who sees my stupid mistake?
So nobody can spot a mistake in my sample code?
Strange, because this line is handled correctly:
Code:
If (PORTB.0=1) or (PORTB.1=1) or (PORTB.2=1) or (PORTB.3=1) or (PORTB.4=1) then
.....
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Re: Who sees my stupid mistake?
I pulled out one of my old 16F628 programs from mothballs, only thing I notice, you have no CONFIG statements.
EDIT: I used this with DEFINE OSC 20
@ __CONFIG _HS_OSC & _WDT_OFF & _PWRTE_ON & _BODEN_ON & _MCLRE_ON & _LVP_OFF & _CP_OFF
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Re: Who sees my stupid mistake?
I set the config parameters in the programmer (as usual).
The values you mentioned are the defaults in my programmer, except the HS mode, that I set manually.
The point is that everything (almost) works.
If I create a loop that does nothing else than: serout2 xxx, delay 1000, I get MIDI information every second.
My main suspect is that the switch(es) are not read correctly in: if PORTB.x =1 then ...
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Re: Who sees my stupid mistake?
Is this the "read modify write" problem?
(I have to look that up whenever I encounter weird problems)
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Re: Who sees my stupid mistake?
Quote:
Originally Posted by
RuudNL
I set the config parameters in the programmer (as usual)...
What if you set them in the program? Maybe something is wonky with your programmer config. (total wild guess, just eliminating stuff)
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Re: Who sees my stupid mistake?
Quote:
Originally Posted by
RuudNL
...If I create a loop that does nothing else than: serout2 xxx, delay 1000, I get MIDI information every second.
My main suspect is that the switch(es) are not read correctly in: if PORTB.x =1 then ...
Blinking a LED confirms if your timing is running at the speed you think it's running at.
I usually go for LED 1/2 second OFF, 1/2 second ON, just to know my OSC is running as it's supposed to.
EDIT: Hm, yeah, but you're getting a SEROUT every second already, so not sure what else to check.
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Re: Who sees my stupid mistake?
I never had problems setting the config parameters in the programmer, but I will try that anyway...
I have a feeling that the problem is in the line:
Code:
if PORTB.0 = 1 then '<---- this line?
Serout2 PORTB.7, 16384+12, [144, 44, 127] ' Rewind
endif
The strange thing is that the switch status IS correctly read in this part:
Code:
Debounce:
Pause 20 ' ? shorter ?
If (PORTB.0=1) or (PORTB.1=1) or (PORTB.2=1) or (PORTB.3=1) or (PORTB.4=1) then
PORTB.6 = 1 ' ADDED TO CHECK!!
goto Debounce ' Button still pressed?
else
PORTB.6 = 0 ' ADDED TO CHECK!!
endif
Goto Progstart
So PORTB.6 is high as long as a button is pressed.
And a loop Serout xxx/ Pause 1000 spits out a burst of MIDI data every second, so it doesn't look it is a config problem.
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Re: Who sees my stupid mistake?
Instead of this
Code:
if PORTB.0 = 1 then '<---- this line?
Serout2 PORTB.7, 16384+12, [144, 44, 127] ' Rewind
endif
try this
Code:
if PORTB.0 = 1 then '<---- this line?
High LED
Pause 100
Low LED ' Rewind
endif
Set LED to a Port and see if it blinks.
Ioannis
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Re: Who sees my stupid mistake?
It doesn't. I tried already:
Code:
If PORTB.0 = 1 then
PORTB.6 = 1
else
PORTB.6 = 0
' and loop...
PORTB.6 never gets high!
I can't wrap my head around it...
In the past I've written considerably more complicated code, usually with success.
I think I'll sleep on it and try again from scratch tomorrow!
Thank you everyone for your thoughts!
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Re: Who sees my stupid mistake?
Then fried PIC maybe?
Ioannis
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Re: Who sees my stupid mistake?
I doubt it... It is a brandnew one!
What I find extremely strange, is that it seems the status of PORTB.x is not read in:
Code:
if PORTB.0 = 1 then
Serout2 PORTB.7, 16384+12, [144, 44, 127] ' Rewind
endif
But IS read in:
Code:
Debounce:
Pause 20 ' ? shorter ?
If (PORTB.0=1) or (PORTB.1=1) or (PORTB.2=1) or (PORTB.3=1) or (PORTB.4=1) then
PORTB.6 = 1 ' ADDED TO CHECK!!
goto Debounce ' Button still pressed?
else
PORTB.6 = 0 ' ADDED TO CHECK!!
endif
Goto Progstart
If it was a faulty PIC, this wouldn't work in both cases.
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Re: Who sees my stupid mistake?
Is it possible that you have high capacitance on the port B pins?
Try to add pause 10 every after command and see how it goes.
Ioannis
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Re: Who sees my stupid mistake?
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Re: Who sees my stupid mistake?
In the meantime there is some progress:
Code:
CMCON = 7 ' Digital mode
DEFINE OSC 20 ' 20 MHZ OSC.
TRISB= %00111111 ' PORTB 6/7=Output 0..5=Input
Progstart:
if (PORTB & 1) = 1 then
Serout2 PORTB.7, 16384+12, [144, 44, 127] ' Rewind
endif
if (PORTB & 2) = 2 then
Serout2 PORTB.7, 16384+12, [144, 46, 127] ' Fast Fwd.
endif
if (PORTB & 4) = 4 then
Serout2 PORTB.7, 16384+12, [144, 48, 127] ' Stop
endif
if (PORTB & 8) = 8 then
Serout2 PORTB.7, 16384+12, [144, 50, 127] ' Play
endif
if (PORTB & 16) = 16 then
Serout2 PORTB.7, 16384+12, [144, 52, 127] ' Record
endif
Debounce:
Pause 100 ' ? shorter ?
If (PORTB.0=1) or (PORTB.1=1) or (PORTB.2=1) or (PORTB.3=1) or (PORTB.4=1) then
goto Debounce ' Button still pressed?
endif
Goto Progstart
This works, as long as I comment out these lines:
Code:
' If (PORTB.0=1) or (PORTB.1=1) or (PORTB.2=1) or (PORTB.3=1) or (PORTB.4=1) then
' goto Debounce ' Button still pressed?
' endif
The idea is of course to prevent that the same data is sent multiple times, so I want to wait until a button is released.
But the these lines seem to avoid that PORTB is read again.
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Re: Who sees my stupid mistake?
It seems the problem is solved. (Although I still don't understand why my first attempt didn't work...)
Now I use BUTTON as included in Picbasic. I don't like all the labels, but at least this works now!
Code:
'* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
'* MIDI Remote for Reaper 20 MHz resonator (HS) *
'* PIC16F628 *
'* PORTB.0 = Rewind *
'* PORTB.1 = FastFwd. *
'* PORTB.2 = Stop *
'* PORTB.3 = Play *
'* PORTB.4 = Record *
'* PORTB.7 = Output *
'* Version 1.0 03 March 2024 *
'* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
CMCON = 7 ' Digital mode
DEFINE OSC 20 ' 20 MHZ OSC.
'DEFINE BUTTON_PAUSE 50 ' Is this needed ?
TRISB= %00111111 ' PORTB 6..7=Output 0..5=Input
BTN1 var Byte ' Button variables for internal use
BTN2 var byte
BTN3 var byte
BTN4 var byte
BTN5 var byte
BTN1 = 0 ' Initialize button variables
BTN2 = 0
BTN3 = 0
BTN4 = 0
BTN5 = 0
Progstart:
BUTTON PORTB.0, 1, 255, 0 , BTN1, 0 , But2
Serout2 PORTB.7, 16384+12, [144, 44, 127] ' Rewind
But2:
BUTTON PORTB.1, 1, 255, 0 , BTN2, 0 , But3
Serout2 PORTB.7, 16384+12, [144, 46, 127] ' Fast Fwd.
But3:
BUTTON PORTB.2, 1, 255, 0 , BTN3, 0 , But4
Serout2 PORTB.7, 16384+12, [144, 48, 127] ' Stop
But4:
BUTTON PORTB.3, 1, 255, 0 , BTN4, 0 , But5
Serout2 PORTB.7, 16384+12, [144, 50, 127] ' Play
But5:
BUTTON PORTB.4, 1, 255, 0 , BTN5, 0 , ProgStart
Serout2 PORTB.7, 16384+12, [144, 52, 127] ' Record
Goto Progstart
The moral: never try to reinvent the wheel!
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Re: Who sees my stupid mistake?
I think the first version should work - but do so quite unreliably.
The reason: If the button being pressed happens to FIRST be checked in the debounce routine the code will be stuck there until the button is released and no action will be taken.
One would think that if you have played with this for some time it would at least sometimes be detected at the "correct" place before falling into the debounce though.
It would probably be a better idea to GOSUB the debounce routine after the SEROUT2 statement or simply:
Code:
if (PORTB & 1) = 1 then
Serout2 PORTB.7, 16384+12, [144, 44, 127] ' Rewind
WHILE PORTB.1 : WEND
PAUSE 10 ' Or whatever
endif
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Re: Who sees my stupid mistake?
Henrik, I think this does not explain why code in post #4 also does not work as the RuudNL says.
Ioannis
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Re: Who sees my stupid mistake?
You mean this:
Code:
Progstart:
if PORTB.0 = 1 then
Toggle PORTB.6
endif
Debounce:
Pause 20 ' ? shorter ?
If PORTB.0=1 then
goto Debounce ' Button still pressed?
endif
Goto Progstart
If so then it's the same potential issue. The PIC runs thru this short program in a couple of microseconds (lets say 20), except for the PAUSE 20 where it spends 99.9% of its time. The likelyhood of the button being pressed during this time and therefor NOT cause the output to toggle is 999 in 1. In the initial code the PAUSE was even longer further decreasing the chanse of the button being polled outside of the debounce routine. Run the code, press the button a few thousand times it "should" toggle the output at least once.
That's my theory and I'm sticking to it until someone comes up with a better one :-)
/Henrik.
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Re: Who sees my stupid mistake?
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Re: Who sees my stupid mistake?
What happens if you just sit on the button?
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Re: Who sees my stupid mistake?
Unless you happen to sit down at EXACTLY the right time your ass will be stuck in the debounce loop.
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Re: Who sees my stupid mistake?
Indeed Henrik. You are absolutely right!
Now I recall I had the same issue once and instead of loose my time trying to find the strange error, i went off to a state machine logic and kept my sanity!
Ioannis
