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CaptainBoing

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Joined: 07/09/2016
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Posted: 07:54am 02 Oct 2018

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Hello forum.

I have a project using a 28 pin '170 that requires to COUNT on a pin that is not specifically able to do it i.e. not pins 15 - 18. It's potted and the only spare pins brought out are 23 & 25 so no opportunity to adjust -

I had a look through the embedded C Functions in the firmware but although there is a lot of really useful stuff to add "soft" ports and other nice stuff, count is not one of them.

It's not particularly high frequency (<5KHz) Has anyone tried this before? Method? any success?

I tried with the following but the best I could get is about 100Hz

dim integer n,m

timer=0
do
if pin(23)<>m then n=n+1:m=not m
loop until timer >=999

? n,m,timer

Thanks in advance for any help

Edited by CaptainBoing 2018-10-03

matherp
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Joined: 11/12/2012
Location: United Kingdom
Posts: 10572

Posted: 08:50am 02 Oct 2018

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Pin 25 RB14 can be used as the input clock to timer 5 or as an alternative to INT1.

The simplest solution which could work is to set up pin 18 as a count input and then call a CFunction which reallocates INT1 to RB14. Then in theory COUNT would work on pin 25 - to be proven!!!!.

matherp
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Posted: 09:28am 02 Oct 2018

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OK this works but it of course assumes you aren't using pin 18 for anything

pwm 1,10000,50 'connect pin 4 to pin 25 for test purposes
setpin 18,CIN
Remap()
pause 1000
? pin(18)
end

CSub Remap
00000000
3C02BF81 8C43FA04 24040002 7C831804 AC43FA04 03E00008 00000000
End CSub

CaptainBoing

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Posts: 2171

Posted: 09:41am 02 Oct 2018

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Thanks Peter.

I did look at the ChangePin CSub in the firmware distribution but couldn't see how to make it work to get the count onto another pin.

What you show above looks really useful but sadly I am limited with what is available and the project has a RTC, so pin 18 is in use.

The count pins were used fairly rapidly because of their 5V tolerance (although they have opto-isolators on their inputs also) and now a change is required after the module has been in service for a while - even so it is potted so I have no opportunity to re-jig the pins used.

Here is a map of what I have available, the three spares are the only stuff available.:

With some inconvenience, it would be possible to re-assign a pin, say 15 or 16 but if I can get round this with some clever software so much the better. It may be I am out of options. I thought about using the soft i2c from the embedded library, but the thing is potted so I can't get to them anyway

cheers

h

Edited by CaptainBoing 2018-10-03

matherp
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Posted: 11:38am 02 Oct 2018

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See the new thread for a solutionEdited by matherp 2018-10-03

CaptainBoing

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Posted: 12:04pm 02 Oct 2018

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Amazing!

thanks so much!

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