Delayed interrupt

[David Stephenson]

I have a push button attached to the interrupt pin. When it is pushed the interrupt takes about 2 minutes to take effect.
Any ideas what is going on. I'm using a 16LF1705 and I've sucessfully managed to get a similar arranged interrupt to work with a different circuit.
Here's the code

#chip 16F1705,.25
#config OSC=INTOSC, MCLRE=Off, WDT=off, boren=off
'I2C settings
#define I2C_MODE Master
#define I2C_DATA PORTc.4
#define I2C_CLOCK PORTc.5
wait 200 ms

dir portc.3 out
dir portc.2 out
dir portc.1 out
dir portc.0 out
dir porta.2 in
dir porta.1 in
dir porta.0 in

set portc.3 off
set portc.2 off
set portc.1 off
set portc.0 off

ht=0
kint=0:jint=1
option_reg.7=0

wpuc=b'00110000' 'i2c pins
wpua=b'00000111' 'front buttons
wait 200 ms

on interrupt extint0 call wakeup
id=0
dim pressure as word
dim zht as word

dim xx1 as word

dim alt as word
dim alt1 as word
dim d11 as word

wait 500 ms

SL=0x7C 'DISPLAY ID
COMSEND=0x00 'display COMMAND send
DS=0X40      'display DATA send

'Main loop
    'Send start
'INITIALIZATION
I2CStart
I2CSEND(Sl)
I2CSEND(Comsend)
I2CSEND(0x34) 'initialize 16x1
'i2csend(0x38) '16x2
I2CSEND(COMSEND)
I2CSEND(0x35) '16x1
'i2csend(0x39) '16x2
I2CSEND(0x10) 'osc set to slowest
I2CSEND(0x77) 'contrast low byte=3 now 5 now 7
I2CSEND(0x54) 'pwr booster on
I2CSEND(0x6F) 'follower
I2CSEND(0x0C) 'on/off
I2CSEND(0x01) 'clear
I2Cstop
iicwrite(0x2b,b'00000100') 'press correction +16 Pa
'iicwrite(0x2b,b'00010101') '+84
iicwrite(0x2c,b'00010000') 'temp correction add 1.0°C
'3.6Pa for every foot
'12 Pa per m
'ht=44 'height above sea level in meters
'ht=22
zht=ht*12
zht=100
'iicwrite(0x12,b'10000000') 
start: 
do
q1=q1+1
if q1=2 then q1=0
'iicwrite(0x26,b'00111010') 'bar and sample 128
iicwrite(0x26,b'10111010') 'bar and sample 128 alt
'iicwrite(0x26,b'00100010') 'bar and sample 16
WAIT 500 ms 'sampling time
'sleep
'nop
wait 1 sec
iicread(0x01,p1)
iicread(0x02,p2)
iicread(0x03,p3)
iicread(0x04,b1)
iicread(0x05,b2)
b2=b2/16
b2=((b2*10)+8)/16

'this is the output to the lcd
if b2=10 then b2=0:b1=b1+1      
A1=b1/100
A2=b1%100
A3=A2/10
A4=A2%10

alt1=p3/16
alt=[word]p1*256+[word]p2
n1=0
if alt>32768 then alt=65535-alt:n1=1
xx1=2*alt+(8*alt)/10+5
xx1=xx1+alt1*328/160
xx1=xx1/10+3*alt

pressure=xx1

z1=pressure/10000 
d11=pressure%10000
z2=d11/100 
z3=d11%100 


I2CStart
I2CSEND(Sl)
I2CSEND(Comsend)
i2csend(0x01) 'clr
i2cstop
I2CStart
    I2Csend(Sl)
    I2Csend(DS)
i2csend(32)
if n1=1 then i2csend(45)
if n1=0 then i2csend(43)
    'I2CSend ((z1/10)+48)
    I2CSend ((z1%10)+48) 'data long
    I2CSend ((z2/10)+48)
    I2CSend ((z2%10)+48)
    I2CSend ((z3/10)+48) 
    I2CSend ((z3%10)+48)
i2csend(32)


i2csend(32)
i2csend(102)
i2csend(116)
i2csend(32)
i2csend(kint/10+48)
i2csend(kint%10+48)
i2cstop





Loop
sub iicread(adr,vlr)
i2cstart
i2csend(0xc0) 'send to
i2csend(adr) 'read id
i2crestart
i2csend(0xc1) 'read from
i2creceive vlr ,nack
i2cstop
end sub
sub iicwrite(adw,vlw)
i2cstart
i2csend(0xc0)
i2csend(adw)
i2csend(vlw)
i2cstop
end sub





sub wakeup
kint=kint+1
'if kint>1 then kint=0
wait 5 sec

end sub

[kent_twt4]

The interrupt and INT pin look to be set correctly; same goes for the OSC.

There is a typo in the iicread sub, could that be hanging the code?
"i2creceive vlr ,nack"

[Anobium]

Please post your ASM file as an attachment. I would like to review the oscillator settings.

Thank you.

[Anobium]

Please post your ASM file as an attachment. I would like to review the oscillator settings.

Thank you.

[David Stephenson]

Yes it's a curious error. It would seem the interrupt is being captured, but it is not going to the sub WAKEUP and then the interrupt flag is not being reset. I've found that the following line overcome the problems

if intcon.1 = 1 then wakeup
set intcon.1 off

Anyway I have attached the ASM

[Anobium]

Thank you.

I recommend you upgrade your Great Cow BASIC installation. The later releases address specific issues with the 16f1705 chipset range.

Whilst an upgrade may not fix the issue - it will enable us to provide the best resolution.

Backup you existing install (a complete set of folders as the backup), and, install the latest release.

Retest. Post the new GCB source file and the asm as a zip please.

[David Stephenson]

It does much the same thing.

[David Stephenson]

Ah I see I can only attach one file.

[Anobium]

I have reviewed the code.

I would expect a some delay as you describe.

Before I advise. Are you using the IDE to write this code? or GCGB?

[Anobium]

I am going offline for the day. I had alread reformated so I could review the code. I would check ALL the if-then-endif statements. I am not sure how to handle single line if-then statements - I do not use them.

I have added a new #define as this will prevent interrupt from being turned on/off in the i2c handler but this may introduce an issue with I2C timing.

Do try - the define may resolve the issue.

[William Roth]

Divide and Conquor. Instead of debugging the program as a whole why not try simple code first to test basic wake from sleep functionality on this specific chip at such a low clock speed. If the code below does not work as expected then the Chip Data file may need to be looked at for Registers & bits. ( This same code works ok on an 18F25K22) .

However...
I also tested wake from sleep on ext int in a large program that uses an I2C LCD and SPI . It seem ok at first but.... If I repeatedly trigger the interrupt pin. The LCD eventually stops working and the
program appears to hang somewhere in the LCD or I2C code. Montoring the FOSC/4 on the clock out pin show that the interrupt still works (system clock still stops & starts with button press)

Wrapping all I2C/LCD functions with INTOFF and INTON seemed to stop the hangs.

You can test if the interrupt is working by enabling clock out in the config and looking at the system clock with a scope. on the 16F1705 PortA.4 will need to be freed up to do this.

My question sbout the 16F1705 and related code is ... Is the interrupt really delayed or is IC2 failing?

If the code below works and then if checking the clock using normal code shows the clock starting & stopping then the interrupt functionality is ok. If the code below fails then it may be registers and bits related to interrupts, PPS, or even OSC problems.

It might could even be that the LCD needs to run at a faster speed. I would try 500K and then 1Mhz and see if the same problem occurs.

 #chip 16F1705,.25
 #config OSC=INTOSC, MCLRE=Off
 #Config WDT=off, boren=off

 '//Connect an LED to Pin 2 
 '// Via 1K resistor

#Define LED PORTA.5 Pin 2  
DIR LED OUT

'//INT0 is on PORTA.2 PIN 11
'// Pull Pin Low with 10K resistor
'//Default INT on rising edge 
On interrupt extint0 call Test_Interrupt
Set LED OFF
 Wait 5 Sec
 '------------------------
Do
    Repeat 2
         Set LED ON
          wait 200 ms
          Set LED OFF
          Wait 200 ms
     End Repeat
     SLEEP   '// Waiting for INT
     NOP
Loop
'-------------------------

Sub Test_Interrupt
      NOP
      Repeat 5
           Set LED ON
           wait 200 ms
           Set LEd OFF
           Wait 200 ms
       End repeat
       Wait 2 Sec
End Sub

[David Stephenson]

Yes the interrupt is working as the INTCON.1 bit is set.
What is happening is the program is not branching to the interrupt subroutine (wakeup) and the INTCON.1 flag bit is not being reset.
If I use the interrupt to wake from sleep it happens immediately, but it continues to break out of sleep several more times (maybe around 5-10) before the sleep works properly once more.
I've got another circuit working with the same I2C display(MCCOG21605) and the interrupt works fine so it must be the rather more involved I2C two-way communication with the pressure sensor (MPL3115A2).

[William Roth]

Quote:

If I use the interrupt to wake from sleep it happens immediately, but it continues to break out of sleep several more times (maybe around 5-10) before the sleep works properly once more.

This is rather odd behavior. Have you sustematically removed/disabled sections of code to try to positively determine determine the root cause ?

A simple question but I have to ask. Is there a resistor from the interrupt pin to ground to prevent it from, floating ?