ISP cable doesnt work with PONYPROG

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Hi Freaks
I have built the ISP loader using the 74HC245 which is an octal tristate buffer from this site http://chaokhun.kmitl.ac.th/~ksw...

but as soon as i tried to work with the PONY PROG i keep on getting a "missing device massage" although there is a 8515 .

Does any one knopws how to calibrate the PONY PROG or some thing that i need to do ??

Thanks

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Hello,
While I haven't built that EXACT cable, I've used several cables that have comparable schematics with PonyProg and they all seem to work.

Several things to check here:
-Do you have the pinout mapped properly? In other words. have you double-checked the ISP connectors to make sure they are going to the pins you think they are? I built a board several years back where I had the mirror image of the connector down, and nothing worked until I figured that out.

-Have you ever programmed the chip before, or is it fresh from the factory? Depending on how you have your internal programming fuses set on the 8515, it may not be able to program with the clock source you are providing (how are you clocking it? internal oscillator? external crystal?) Search the forums for "fuse settings" and you'll get tons of hits for accidental fuse settings that prevent programming.

-In your 8515 circuit, do you have the MOSI, MISO, or SCK lines tied high or low through some external means (resistor)? I also made this blunder many moons ago, where I wanted an i/o line tied low during normal operation, so I tied it to ground with a resistor, which prevented the reprogramming from working right.....

Let us know what you find....hope this helps....

Regards,
John O.

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Another suggestion is cable length. I've had some weird problems with that circuit and ponyprog when the ISP cable was too long. Try to keep it as short as possible.

-carl

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Hi FREAKS....
Thank you for your quick reply :D

ajo115......
your ideas for double checking were ok \altough i did the checking and found nothig wrong ( so this is not it)

The 8515 was programmed before on the STK200 board tha i have .
The 8515 is working properly ( i loaded a small program that makes the PORTB blonk and i monitor it with a SCOPE) SO THIS IS NOT THIS TOO!!

The clock that i am usinng is 4Mhz and it is external ( works fine because if it wouldnt work fine then the 8515 would not blink the PORTB)
I dont know if there is any recomandation concernning to the clock value when you are using the PONY PROG usnless i am mistaken here.

I have connencted the MISO MOSI according to the file that i added in the first massage and there was no pull up/down resistors so i didnt connect itto any of it but i dont think that this is neccecery becaues after all we are using a TRI STATE buffer which suppose to give a HIGH Z when not working with one of the pins ...again correct me if i am wrong.

can you send me the web site of the fuse forum and if you can explain what is the fuse configuration for the 8515 because i have never used it...What i mean is that i have programed the 8515 using the STK200 and never been told to fix the fuses please advise :?:

As for Carl....when you are saying that the cable should be short did you mean that the ISP cable should be as short as you can or did you mean for the whole unit that comes out from the parallel Port?

Thank you for your helpful replies...........waiting