Cable tester code help

[XLSERVICE]

Hi Guys

I am building a cable tester and need some assistance with a bit of code.
This bit of code is used when testing the cable for intermittent connections.

This is what I would like to use, but it returns syntax errors..
If b0>0 and pin0 = 0 then : low portb (b0-1) : high portc 5 : b12=1 : endif

The value in 'b0' represents the output port that is connected (via the cable under test) to input 0.
If input 0 goes LOW then turn off the portb OUTPUT that is driving it (in this case the value in b0-1)
This line would be repeated for b0 to b9.

Basically I am asking how do I change the port number in relation to a variable.

Cheers
Alan

 

[hippy]

You will have to use a temporary variable to hold the value-1 ...

If b0>0 and pin0 = 0 then : b13=b0-1 : low portb b13 ...

Additionally, "PORTB" isn't supported for the current PICAXE range. If these are the normal output pins, simply use "LOW b13".

If it is more complicated than I understand it to be you will have to provide further details on what operation you require.

 

[XLSERVICE]

Cheers. That solution should work fine..
portb and Portc seem to work fine. I am using a 40X1 Picaxe.

I will try 'b' and 'c' instead.. May save me a bit of memory..

Cheers
Alan

 

[westaust55]

Cheers. That solution should work fine..
portb and Portc seem to work fine. I am using a 40X1 Picaxe.

I will try 'b' and 'c' instead.. May save me a bit of memory..

Cheers
Alan

Alan,

from your response not sure you have fully understood.
"b" and "c" alone will not work and "portB" as a keyword is not supported.
Port B is the normal outputs on the 28X1 and the 40X1.

as hippy has suggested use:

b1 = b0 - 1
If b0>0 and pin0 = 0 then : low b1 : high portc 5 : b12=1 : endif

Presume that b1 is not lower than 1. If b0 = 0 then due to "roll-over" b0-1 = 255

 

[XLSERVICE]

Thank's Guys
Having read this a couple of times, I think I now understand.

As Port B pins are the default outputs for the Picaxe, the port does not need stating. So LOW Portb 5 should be replaced with LOW 5 or, in my case the port number can be replaced with a variable eg. LOW b13....

The rest of my cable tester is currently working fine, however, I have used Porta, Portb and Portc throughout.

Performing the subtraction within the IF statement should avoid 'rollover' as if the variables b=0 the IF line will not be entered.

Cheers
Alan

 

[westaust55]

Alan,

sorry but you cannot do any maths as part of the IO level (high/low) setting

so LOW (b0-1) is going to give you a syntax error.


please look again at what I wrote at port 4 in the second code box.

Likewise just for your information, you cannot do maths as part of the test within an IF...THEN command

for example

IF b0 > b1+2 THEN GOTO main​

will give a syntax error