using pin 7 on 08m for and output

[sbscott]

I am building a fan controller and need to use pin 7. When I do, after removing the rs232 connector after programming, I get a a block of digital "1" (seen on my scope) which triggers the relay it operates. How do I "silence" pin 7 when in a "0" condition"
See code below.

'#08m  '4-1-2012

'out 0 fan
'out 2 camera
'b1 is therm
'b2 is pot
high 2
x:
debug b1
readadc 4,b1
readadc 1,b2
pause 100
if b1>b2 then gosub fanon
if bit2=1 then goto x
if b1<b2 then gosub fanoff
pause 500
goto x

fanon:
if bit1=1 then re
bit1=1
high 0
return

re:
return

fanoff:
low 0:bit1=0
bit2=1
return

thanks!

 

[Technical]

It's the 'debug' sending out data - leg 7 is also the serial transmit. Simply remove the debug command.

 

[sbscott]

It's the 'debug' sending out data - leg 7 is also the serial transmit. Simply remove the debug command.

Gotcha! Thanks. I am assuming that pin7 works as the other output pins when debug is NOT turn on.

 

[tony_g]

Gotcha! Thanks. I am assuming that pin7 works as the other output pins when debug is NOT turn on.

yep, i occasionally use pin 7 on my 08m2 with high/low commands without a debug at it works like the other outputs

 

[nick12ab]

I am assuming that pin7 works as the other output pins when debug is NOT turn on.

Like tony_g describes, yes, but high and low signals will also be transmitted on this pin when downloading a program or if the Serial In pin manages to become high before the disconnect command (if any) is issued. Some Rev-Ed project boards have a jumper switch on them to allow you to connect the output to the programming jack only and not the normal output pads, so you could re-use this idea if the quickly alternating output would be an issue while downloading.

Commands that require a bi-directional pin (such as readtemp) won't work either.

yep, i occasionally use pin 7...

Rev-Ed's convention is to call physical pins legs and to call pin names in BASIC pins.

To avoid confusion this manual always talks about ‘legs’ where
referring to the external physical location of the input/output pin.