GPS NMEA antenna aiming tracker.

Thread Starter

camerart

Joined Feb 25, 2013
3,842
Hi,

I've been adapting the first motor by making a quadrature encoder, and the 'photo interrupts' I've used are: http://uk.farnell.com/sharp/gp1s096hcz0f/photointerrupter/dp/1618497?Ntt=161-8497

I need more to adapt the second motor and some for a friend. (6 minimum) I just went to order more interrupts and find they are now discontinued:eek:

If anyone knows where I can find them (or very similar), please let me know. I'm in the UK.

EDIT See attached photos:

Cheers, Camerart.
 

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Thread Starter

camerart

Joined Feb 25, 2013
3,842
hi C,
Which special features of the opto that you have do you need in a replacement type.??

E
Hi Eric,

The closer to the original interrupters size the better. In particular the ones marked in the attached diagram. The more the replacements are larger, makes it increasingly difficult.

I've been searching for similar, and might find some. I have a few candidates so far.

Cheers, C.Opto dimensions.jpg

Opto and disk.jpg
 

Thread Starter

camerart

Joined Feb 25, 2013
3,842
Element14 in the UK have a good variety.

Thanks Roman,

What I saw on that site were a bit large.

I found these: http://www.goldmine-elec-products.com/basket.asp but they don't ship to here:(

Still looking.

EDIT: Farnell contacted me with an alternative (I couldn't find them!), so I'm back on the road:)
EDIT2: When they arrived they were in an Element 14 box (Farnell)

C.
 
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Thread Starter

camerart

Joined Feb 25, 2013
3,842
hi C,
Attached the latest program.
I see that Oshonsoft has the Arctan function in the compiler.

In case you dont have it yet , I have used the our Arctan function, renamed myarctan.

E
BTW: I cannot suggest a problem with the data radio link you have running.:confused:
Thanks Eric,

I'll try it now.
I'll also check if I've got Arctan, and update if necessary.

Regarding the Data radio link, I think it might be interference, and will hopefully be eliminated later

Cheers, Eric.
 

ericgibbs

Joined Jan 29, 2010
21,460
hi,
Ref the Arctan Basic function, its only 0deg thru 45deg and its slow IMO,
2100uSec compared to the 500uSec we are currently using.

E
 

Thread Starter

camerart

Joined Feb 25, 2013
3,842
hi,
Ref the Arctan Basic function, its only 0deg thru 45deg and its slow IMO,
2100uSec compared to the 500uSec we are currently using.

E
Hi Eric,

When I tried to compile your program, it failed at anything with 'sign' in, so I was just about to update Oshonsoft.

Does your last message mean that you won't be using these Oshonsoft maths functions?

EDIT: I don't know exactly what it means but I seem to recall octants instead of quadrants. Does this help the 45deg problem?

C.
 

ericgibbs

Joined Jan 29, 2010
21,460
Hi Eric,

When I tried to compile your program, it failed at anything with 'sign' in, so I was just about to update Oshonsoft.
It compiles on my PC using the previous and last versions of Oshonsoft.
I have double checked and I don't see any error.???

NOTE: if you use the SIGN as a DIM it will tell you that its a System Keyword and it cannot be used as a label.

Does your last message mean that you won't be using these Oshonsoft maths functions?

It means that the Arcsign function we have used for last few programs is OK and I suggest we continue to use them.

EDIT: I don't know exactly what it means but I seem to recall octants instead of quadrants. Does this help the 45deg problem?

The 45deg is ONLY a problem if you use the Oshonsoft Arcsin statement in your programs.

C.
hi,
Which version of Oshonsoft PIC18IDE are you using.?
E
 

Thread Starter

camerart

Joined Feb 25, 2013
3,842
hi C,
Attached the latest program.
I see that Oshonsoft has the Arctan function in the compiler.

In case you dont have it yet , I have used the our Arctan function, renamed myarctan.

E
BTW: I cannot suggest a problem with the data radio link you have running.:confused:
Hi E,

Just did first test of your program, and it looks good. I'll let you know when I have some proper results.

C.
 

Thread Starter

camerart

Joined Feb 25, 2013
3,842
Hi,

I made a start on the quadrature/motor control program, and soon found my shortcomings!

How do I input QEA an QEB quadrature signals?

Looking at the 18F2431 PDFs including the one I've attached, I can see that this chip is quite a complicated one to use. I think that my simple program isn't using much of the internal 'brains' of the PIC

One thing I notice in the PDF, is there is an index on the opto disk for resetting the count? As I didn't add one is it possible to use external 'say' micro switches as a resets?

Camerart
 

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