Problem with 16F688 and Hserout

[DWV]

I am having a problem getting anything to work with the 16F688. I have built some Midi foot controllers using the 16F628 and they work fine, but I would like to port it over to the 16F688, so I can use the analog inputs. I have also built some projects using the analog inputs on the 12F675 with no problems , but I can't seem to get anthing to work with the 16F688. When I run a simulation in MPLab, it gets stuck in a loop, the problem is that it is not in my programming, but while executing the PBPPIC14.LIB file. Does anyone know of any incompatibilities with the 16f688?
I have attached the code for the project, maybe someone here can let me know what I am doing wrong.
I have also tried it on the 16F88, with the same results.

[mister_e]

few things spring to mind

• DEFINE HSER_BAUD 31250
  Not a valide baudrate see section 10.. i'll prefer use DEFINE HSER_SPBRG or setting SPBRG= and SPBRGH= myself instead... safety sake
  
  ADCON0 = %0000001 ' set VREF to VDD and left justify result
  must be right justified to have a 10 bit a/d result.... ADCON0.7=1
  
  If exp <> expout Then
  what about if you change for: If exp != expout Then
  
  Can be safe to set OSCCON register to tell PIC to run with the external clock... OSCCON.3=1
  
  Can also be safe to clear your variable at the begining... use CLEAR before loop label

[DWV]

I allready caught the ADCON0 mistake. I decided to try the basics, I set all the pins to digital, hooked 2 switches to port a (internal pull-ups enabled) and two LEDs to portc, when I power up the chip the LEDs come on (they should be off) and the switches don't do anything. I think I may have some defective chips, the funny thing is that all 3 of the "samples" I got do the same thing. I'll have to do some more experimenting on them, but I won't have time till the middle of the week, I'll keep you informed of my results.

Dave

[Darrel Taylor]

The simulator in MPLAB can't simulate hardware peripherals like the USART, Timers, CCP modules etc. It gets stuck waiting for something to happen that never does.

It's better to use MicroCode Studio in debug mode. Of course, it's not free.

Also, on the 16F688 the TX is on RC4. In your program, RC4 is set to Input by the TRISC = %00111111 statement. It needs to be an output for HSEROUT to work.

HTH,
&nbsp;&nbsp;&nbsp;Darrel

[DWV]

I caught that one to Darrel, I originally had it set that way, but it made no difference. When I power up the chip, it sends a portamento on command,(I don't know why, it should not) so it seems that the serial port is working, but nothing else is.

here is the code with the typo's corrected.

' PicBasic file for midi footpedal interface using a Pic16F688
' foot pedals must have TRS plugs
' will work with 5-50k linier pots
' set osc to HS when programming

DEFINE OSC 20 ' tell program we are using a 20mhz oscillator
DEFINE HSER_RCSTA 90h ' enable hardware serial port
DEFINE HSER_TXSTA 24h ' enable high speed transmit
DEFINE HSER_BAUD 31250 ' set the baud rate
DEFINE ADC_BITS 10 ' set the number of bits in the sample
DEFINE ADC_SAMPLEUS 50 ' set the sample time

TRISA = %00111111 ' Set PORTA to inputs
TRISC = %00101111 ' set PORTC to inputs
ANSEL = %11110000 ' enable analog 4,5,6,7 the rest as digital
ADCON0 = %1000001 ' set VREF to VDD and right justify result
ADCON1 = %00100000 ' set conversion clock FOSC/32
CMCON0 = 7 ' turn off comparitors
OPTION_REG.7 = 0 ' enable internal pull-ups on porta

C0 Var word ' create C0 to store result from Volume pot
C1 Var word ' create C1 to store result from Expression pot
C2 Var word ' create C2 to store result from Foot Controller pot
C3 Var word ' create C3 to store result from Portamanto Time pot
vol Var byte ' create variable for volume
exp Var byte ' create variable for expression
foo Var byte ' create variable for foot controller
por Var byte ' create variable for portamento time
volout Var byte ' create variable for volume output
expout Var byte ' create variable for expression output
fooout Var byte ' create variable for foot controller output
porout Var byte ' create variable for portamento time output
sw1 Var byte ' create variable to hold switch1 value (sustain on/off)
sw2 Var byte ' create variable to hold switch2 value (portamento on/off)

loop:
ADCIN 4,C0 ' read Volume pot and place value in C0
vol = C0 / 8 ' convert reading to a midi value from 1-127
If vol <> volout Then ' check to see if the value has changed
volout = vol
HSEROUT [176,7,volout] ' send Volume out serial port as midi information
Endif

ADCIN 5,C1 ' read expression pot and place value in C1
exp = C1 / 8 ' convert reading to a midi value from 0-127
If exp <> expout Then ' check to see if the value has changed
exp = C1
HSEROUT [176,11,expout] ' send exptession out serial port as midi information
Endif

ADCIN 6,C2 ' read foot controller pot and place value in C2
foo = C2 / 8 ' convert reading to a midi value from 0-127
If foo <> fooout Then ' check to see if the value has changed
fooout = foo
HSEROUT [176,4,fooout] ' send foot controller out serial port as midi information
Endif

ADCIN 7,C3 ' read portamento time pot and place value in C3
por = C3 / 8 ' convert reading to a midi value from 0-127
If por <> porout Then ' check to see if the value has changed
porout = por
HSEROUT [176,5,porout] ' send portamento time out serial port as midi information
Endif

If porta.0 = 0 Then sw1on ' check sustain pedal
If porta.0 = 1 Then sw1off
If porta.1 = 0 Then sw2on ' check portamento pedal
If porta.1 = 1 Then sw2off

If porta.2 = 0 Then
Hserout [255] ' reset all controllers
Endif

Goto Loop ' go back to continuous monitoring

sw1on:
If sw1 = 0 Then ' check to see if sustain is off
sw1 = 127
Hserout [176,64,sw1] ' turn on sustain
Endif

sw1off:
If sw1 = 127 Then ' check to see if sustain is on
sw1 = 0
Hserout [176,64,sw1] ' turn off sustain
Endif

sw2on:
If sw2 = 0 Then ' check to see if portamento is off
sw2 = 127
Hserout [176,65,sw2] ' turn on portamento
Endif

sw2off:
If sw2 = 127 Then ' check to see if portamento is on
sw2 = 0
Hserout [176,65,sw2] ' turn off portamento
Endif

Dave

[Darrel Taylor]

Dave,

There's a bit of a problem with this section

If porta.0 = 0 Then sw1on ' check sustain pedal
If porta.0 = 1 Then sw1off 
If porta.1 = 0 Then sw2on ' check portamento pedal
If porta.1 = 1 Then sw2off

If porta.2 = 0 Then 
Hserout [255] ' reset all controllers
Endif

Goto Loop ' go back to continuous monitoring

sw1on:
If sw1 = 0 Then ' check to see if sustain is off
sw1 = 127
Hserout [176,64,sw1] ' turn on sustain
Endif

sw1off:
If sw1 = 127 Then ' check to see if sustain is on
sw1 = 0
Hserout [176,64,sw1] ' turn off sustain
Endif

sw2on:
If sw2 = 0 Then ' check to see if portamento is off
sw2 = 127
Hserout [176,65,sw2] ' turn on portamento
Endif

sw2off:
If sw2 = 127 Then ' check to see if portamento is on
sw2 = 0
Hserout [176,65,sw2] ' turn off portamento
Endif

If porta.0 = 1 the program will GOTO sw1off. It will then proceed to sw2on, sw2off and finally go off into LaLa land as there's no way to go back to the main Loop. The last thing you'll see before it dies is the portamento command (assuming conditions are right)

You could changed each of the sw1on: sw1off: sw2on: sw2off: sections to a subroutine ending with RETURN. Then, for the tests...

If porta.0 = 0 Then GOSUB sw1on ' check sustain pedal


Best regards,
&nbsp;&nbsp;&nbsp;Darrel

[DWV]

I tried it that way originally, and it made no difference, I also tried it with GOTO Loop at the end of each subroutine, with the same result.
I have been doing this on two computers, I checked the version on my laptop and it has a RETURN at the end of each subroutine, I just missed it when I typed it into this computer.

Dave