16f88 problems

[mikey11]

I had thrown a 2 second pause in to allow for things to stabilize, then I read the post where the pause should be before the tris statement is made. I'll try that.

I will try removing adcon as well.

The solenoid is hooked up via an output from a digital pin. When the pin goes high it trips a 2N3904 which completes a circuit for a 12V relay which then fires the solenoid itself.

Both the solenoid and the relay have protection diodes in place.

The solenoid is running a regulated air system.

I did have this system working with a 16f819, but my computer crashed and I didn't have a backup (silly me). I can confirm that the general scheme I used components wise has worked completely in the past. The only thing that is substantially different is the pic, and I put more of the components on the circuit board.

removing adcon had no effect, and the pause prior to the tris statements didn't seem to do anything either.

Unfortunately I leave again, and won't have a chance to work on it again for a while. I think these initial statements are where the problem resides. Something transient to do with the interplay between configuration, and hardware just as power is applied.

Can anyone tell me about the difference between ADSEL and ANSEL? I have seen references to ADSEL and the 16f88 by people using other compilers than pbp.

-Mike

[languer]

So from the code and your statement it looks like either the first "if startbutton = 1 then goto checkvalues" is reading incorrectly; or perhaps the first "flashingled = 0" is not being executed.

Your initial settings look fine. You can remove the ADCON1 as this chip does not have this. I would perhaps have the order different (i.e. @device first), but I do not think it should make a difference.

How is the "startbutton" input connected? Is it sharing anything with the solenoid?

How is the "flashingled" connected?

If you disconnect the solenoid output, does the code runs as expected?

[aratti]

'declare inputs and outputs appropriately
PortA = 0
PortB = 0
TRISA = %00111100 ' a.5 is INPUT only
TRISB = %11100100

Try to set portA and B to zero before Tris
What value is your pulldown resistor?

Al.

[mikey11]

'declare inputs and outputs appropriately
PortA = 0
PortB = 0
TRISA = %00111100 ' a.5 is INPUT only
TRISB = %11100100

Try to set portA and B to zero before Tris
What value is your pulldown resistor?

Al.

the pulldown resistor is 1000 ohms.

I won't have the opportunity to try new code for a while, but I will try that when I get a chance.

[Archangel]

the pulldown resistor is 1000 ohms.

I won't have the opportunity to try new code for a while, but I will try that when I get a chance.

I agree with Al, set port latches low before the tris register and make sure RBPU is disabled OPTION_REG.7 = 1

[languer]

The following may correct any R-W-M mismatch condition, but it is a little risky to write to the output latch (even if not an output) when it maybe directly connected to +5V (through the SW):

PortA = 0
PortB = 0

Would an initial read to the port, before the actual loop, do the same?

The RBPU should be disabled by default (unless PBP assigns it behind the scenes).

For these reasons I would have the port connected to +5V through a 10k resistor; and the switch would connect the port to GND (may be through 1k for protection).

The following post may give some ideas (not identical, but helps illustrate): http://www.picbasic.co.uk/forum/show...t=weak+pull-up

[languer]

Forgot to say that should you do this:

For these reasons I would have the port connected to +5V through a 10k resistor; and the switch would connect the port to GND (may be through 1k for protection).

You would change your code to read, "if startbutton = 0".

[mikey11]

So from the code and your statement it looks like either the first "if startbutton = 1 then goto checkvalues" is reading incorrectly; or perhaps the first "flashingled = 0" is not being executed.

Your initial settings look fine. You can remove the ADCON1 as this chip does not have this. I would perhaps have the order different (i.e. @device first), but I do not think it should make a difference.

How is the "startbutton" input connected? Is it sharing anything with the solenoid?

How is the "flashingled" connected?

the button is such that a wire leads from +5v to the switch, then from the switch to the pin and to a resistor to ground.

The LED's are outputs from the pic that have a current limiting resistor of 1000 ohms.

If you disconnect the solenoid output, does the code runs as expected?

I have disconnected the solenoid output with no resolution of the problem.