STK-500 blown - need another AT90S8535-8AC

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Folks:
This may be the wrong forum to post in, so moderator(s), move it if you need to.

I have an STK-500. One of the I/O pins (used for HV-programming) on the on-board 8535 is blown. The AT90S8535-8AC is unavailable for purchase or sample from the standard sources.

I have asked ATMEL if a "blank" AT90S8535-8AC can be used and the firwmare reloaded ... or... if an ATMega8535 can be used as a replacement.

ATMEL tech support says "yes" to new AT90S8535-8AC but "no" to ATMega8535 (because of different signature bytes).

I had also asked if ATMEL could supply the source or HEX file for the on-board AT90S1200 (used for firmware upgrade), which I could disassemble and possibly recode the signature and fuse bytes but the ATMEL answer is "we cannot provide the HEX file for the AT90S1200". I suspect the lock bit is cleared so no firmware reading.

So, my post is this: Anyone have any AT90S8535-8AC available for trade or purchase (at a reasonable cost)?

Or perhaps the source/HEX code for the on-board AT90S1200?

Best regards,
Scott Vitale

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Hmmm--are the schematics different for "classic" STK500s with AT90S8535/AT90S1200 versus "modern" STK500s with ATmega8535/ATtiny2313? Not that I remember.

I guess I see the situation--the '1200 expects a signature of old '8535.

Is the firmware for the modern Tiny2313 well known? Then you could replace both chips.

Octopart and FindChips uncover some AT90S8535. Also check eBay auctions, and the botique/robotics sites that have been around long enough (Dontronics, Sparkfun, ...) to see if they still have a stock.

Lee

NB: I've used STK500s daily for nearly 10 years during production app development. We've never once done a HVPP (or HVSP).

You can put lipstick on a pig, but it is still a pig.

I've never met a pig I didn't like, as long as you have some salt and pepper.

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You might be able to use the source code from the AVR910 appnote as a starting point for modifying the '1200's firmware to work with an ATmega8535.

Some things to look out for:
-Check to see whether or not the pins used for software UART are different between the AVR910 appnote and the STK500 schematics. Modify the AVR910 source code as necessary.
-Check to see whether or not the pins used for the bitbanged ISP interface is different between the AVR910 appnote and the STK500 schematics. Modify the AVR910 source code as necessary.
-You'll need to modify the AVR910 source code so that it checks the status of the STK500's PROGRAM button on power-up.
--If the button is initially open during power-up, leave all other I/O pins in the high impedance state and enter a never-ending infinite loop.
--If the button is initially pushed during power-up, hold the ATmega8535 in reset, and start running the AVR910 appnote's main loop.
-Atmel's final release of reference AVR910 code predates the ATmega8535, so the AVR910 reference design will have to be modified to know about it. The ATmega8535's AVR910 device code is 0x69; it is a page-programmed device, with a 32-word page size. It has read and write access to Flash, EEPROM, Lock, and Fuse bits.
-While you're at it, you should modify the AVR910 source code so that it only reports back the device ID bytes corresponding to an ATmega8535, to reduce probability of human error.
-A blank ATmega8535 will be configured to use its internal 1MHz RC oscillator, so you'll need to hack up a standard ISP interface through AVR Studio's default programming interface to initially configure the '8535 to operate the STK500's crystal. That way the AT90S1200 will be able to piggyback off it to perform the rest of the programming procedure.

These overly simplified modifications would not allow you to use the automated upgrade procedure, but they should be enough for you to use AVRprog as directed in the "Manual Firmware Upgrade" described in AVR Studio's help files.

NOTE: I have not tried any of the above instructions myself. Although I have no reason to suspect they will fail, I also cannot guarantee that they will work. If you follow my suggestion, you do so at your own risk.

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The original download link does not work anymore so here it is:

Attachment(s): 

John Samperi

Ampertronics Pty. Ltd.

www.ampertronics.com.au

* Electronic Design * Custom Products * Contract Assembly

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Update: 2015-1230: I have found some of the original AT90S8535's for about US$7.50 each on eBay. So anyone having this same problem might look there for replacement parts.

 

Folks:
Thanks for all the input. Looks like Colin and some others have had the same problem I have.

The last link posted contained the files to assist me in my effort. Thanks to the poster for that one too!

Regards,
Scott Vitale

 

Last Edited: Fri. Jun 17, 2016 - 12:32 PM
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Hi,

 

I have a similar problem with my STK500.

The onboard AT90S8535 doesn’t produce PWM for the Vtarget LM317. The other PWM is on.

This problem was occurred after the STK500 was used in a slightly warm environment, where the developed target circuit should designed for.

So, after I read all the posts about dead STK’s I did some measurements and come to the result that the 8535 is defective.

I find some new ones on Ebay, but I’m not sure if replacement works. If I solder a new AT90S8535…..is the remaining AT90S1200 able to flash the clean AT90S8535? Are the default fuses compatible?

I hope for the answer after the last post, but no additional post.

 

Did anyone can help?

 

Regards,

Helix666

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try to update FW first!

 

and if you replace the 8535 then the programming should be a FW update (there is no bootloader function so the 1200 must do a real programming).

 

 

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Hi!

 

This was the first thing after my STK blink frequently with the status LED.

I think I have the 4.17 or 4.18 version of Studio installed and the update.exe in the subfolder structure shows me a “succeeded” after flashing.

But the Vtarget was not come up. I can eliminate the opamp and the lm317 because the PWM is missing.

My only hope is to try an older Studio version with an older Firmware ore to replace the 8535.

And this was my main question. If I replace the controller…..Is the 1200 able to flash a clean 8538.

 

I'm open for any suggestions!

 

Regards,

Helix666

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what about the voltage feedback?

Perhaps the PWM works but no need, because the feedback is at an end!

 

add:

Try change the voltage from studio (I have had a board that sometimes lost the setting (and then it jumped from 3.3 to 5V :(  so I ended up keeping the 5V and dropped the voltage with 2 diodes).

Last Edited: Wed. Feb 7, 2018 - 03:13 PM
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I doesn't look to the feedback, because VTG is only through a voltage devider connected to an ADC. With an connected scope on PWMA line there is no one pulse when switching on the STK500.

With connected scope on PWMB you can see  the change in duty cycle when changing the voltage in control panel.

But PWMA is dead. Atmel says, that a voltage gap greater than 0.3 Volt between set and measure voltage causes in an shut down of both VTG and Vref. But I can't find a short cut and Vref works.

Yesterday I also installed the earliest version of Studio4 and run the update.exe to flash the STK500 firmware, but no change in behavior. Sometimes I read about the "old" and "new" version of STK500 where the "old" one are not supported on newer firmwares.

All my hope is on replacing the AT90S8535 with a new one.

 

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Helix66..

Are you interested to buy a STK500?

perhaps shipping will be expensive. 

I have one stk500 new ( not used ) and one used but ok.

I have STK600 too .. never used . not like it too big.

Now I use only AVRISP or ATMEL ICE.

Thierry

 

Thierry Pottier

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Thank you for offer.

But I'm more interested in repair my old one and find a reason why it's broken.

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Hi!

 

Thank you to sparrow2 for the cofirmation to easy replace the AT90S8535.

I found some AT90S8535 on the bay and replaced it.

After running the update.exe the STK500 works again. **Great**

But why the old one dies in that way, only the PWMA was defect, stays a mystery.

I hope for another long STK500 life :-)

 

Regards,

Helix666

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I can not speak so much about the AT90S8535 bur I was running some product with the AT90S8515 and if you short the pin or too much current it burn! ( short accidentally not by design)

I must add a serie resistor too protect.

never get this problem with the ATmega8515.

Thierry

Thierry Pottier