can I fix my fried stamp?

jaydag71

·I just finished my working prototype of a bipolar transistor dual H-bridge which has worked great thus far. I built a point to point six months ago and have used it plenty with great results to drive small dc motors in a tiny-tank bot I've built. When I finished the layout and plugged it all together I got some unexpected results.· I stilll haven't debugged them yet but I think the problem is in the upgraded portions of the newer version- an onboard regulator, LED indicator and the decoupling caps and a switch. I tacked in the switch backwards somehow!

·Anyways, when I run the test program the "no basic stamp found!" message comes up. I swapped out the stamp for another, unpluged from the dual H and tried again, sucess [noparse]:([/noparse]

·Now I'm sure this is a topic that has been covered in the past, but here it is again...how can I fix my stamp? What are the most likely components that have blown out? The onboard reg is working so I know it isn't going to be that easy. I had the same thing happen to another stamp like device I have called the Ez-Controller (PIC18F252 and everything else needed for a complete self contained PIC solution) and the fix was just replacing the Reg, whew. By the looks of it there are a couple of transistors,·some resistors·and some other tiny device right at the top left·of the board and linked into the Vss, Sout,Sin,ATN. Me thinks the issue is in there somewhere, and if I could find out what it is (some smd logic ic? buffer?) maybe I can try replacing it?

·Also, just throwing this out there but while I am hacking into the stamp, is it possible, pending finding compatible pinout devices, that one could swap out the onboard 24LC16 memory IC for a larger capacity IC? I ask this without knowing the internal workings in firmware/software, but the idea just came through so I figure why not ask...

·Any help with figuring out how to revive my fried stamp would be great! I have a few others to use in the meantime, but chances are that I will end up frying another at some point so knowing what to do about it would be great. Thanks in advance, jaydag71

allanlane5

1. Parallax is pretty good about working with users to 'fix' (replace? I don't know) their burned BS2's. Call their 1-800 number.

2. No, the BS2 only knows how to interface with 2K Bytes of eeprom at a time. Swapping in a larger eeprom doesn't help.
Some BS2 variants (BS2sx, BS2p) do have 'multi-slot' programming.

Paul Bouchard (Parallax)

It is true that Parallax will work with you regarding your damaged stamp. We do offer a 1/2 price·exchange program for this product. Repairing a stamp is usually a more costly venture then simply exchanging the damaged unit for a new unit. Our techs can however test the stamp for failure feedback should you need it. The best way to go about this would be to contact our Tech Support Dept 888-512-1024 and receive a return authorization number. Tech support can take you thru the process steps once contacted

LoopyByteloose

Paul Bouchard is right.
Considering the smallness, the question of available parts, and so on. It is just faster turn around and a better deal to exchange.

The EEPROM on the BasicStamp has a limited lifetime [noparse][[/noparse]maybe 10,000 to 100,000 writes]. My guess is that when you exchange, you start with a fresh EEPROM as an added bonus.

I have only done one DIY repair to my Stamps. I broke a PIN #1 on a BS2p24, so I removed another pin from a damaged IC and attached it as an overlay. I think that is about the limit of cost effective DIY Stamp repairs.

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"If you want more fiber, eat the package.· Not enough?· Eat the manual."········

···················· Tropical regards,····· G. Herzog [noparse][[/noparse]·黃鶴 ]·in Taiwan

jaydag71

·Thanks for the responses! The trade in is something I never knew about, and if I understood what you meant they will also debug your fried stamp and get back to you with those results? Is this a service that involves fees or a free support feature?

·I was more leaning toward the fixin it myself approach, although I can understand the cost to value factor in a DIY verses trade in, I think that you are also factoring in the cost of the time involved in the repair, and for me that isn't a big deal and would rather do it myself so as to know what to do the next time I fry one...I'm sure the actual part cost would be minimal if any (eng samples?)

·I am also working on building an ICD2 this morning, and while reading through the 16F876 datasheet came upon a paragraph stating that the device is pin compatable with other 16Cxxx devices...without downloading the c57 sheet and checking myself, has anyone ever tried doing a PIC upgrade to the BS2 boards if there are indeed pin compatable alternatives? are there freely available source code for the BS2 interpreter firmware or is all this stuff protected. I haven't even tried hacking the stamp but would perhaps guess that the firmware would be in secure blocks or somehow protected otherwise? Just throwing the thought out there but doubt I would ever spend the time investigating- would rather try building my own boards! Again without knowing the internal workings of the stamp, my guess is that the interpreter is similar to a bootloader is many ways, likely loaded in a similar fashion?

·Anyways, again I just thought that with the stamp repairs that the subject would have likely been covered extensively in the past here and that I couls save myself some troubleshooting time with some helpful suggestions about what parts of the device are most likely to fail first-ie, just looking at the stamp, one can see that there is not much to it, there are a couple of transistors (or a diode and tr)·and some other tiny device in the top left corner (buffer logic?). Well due to the error messages I encountered I might guess that the problem lay somewhere in this circuit. I have power from the regulator still so I know it isn't as simple as replacing that. Other than that the only other thing I think could fry is the PIC and or the EEPROM itself.

·Well shoudl get back to it, again thanks fo rthe recommendation!

Gadgetman

I'm sorry, but the BS2 interpreter firmware is protected. Well protected, in fact, as it's what differentiates a normal PIC and a BS2.

The Interpreter isn't a boot-loader. It is a full program, which reads an instruction from EEPROM, interprets it, reads another, interprets that...
What is stored on the EEPROM is what's known as 'tokens' which are codes telling the interpreter what to do next, not machine-code instructions.

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Don't visit my new website...

Paul Bouchard (Parallax)

Jaydag,
Parallax does reserve the right to charge a $10 testing and feedback fee however testing and providing feedback to our customers serves both parties better in the long run. We get a customer that now has a better understanding and knowledge of our products and this hopefully reduces future failures or damaged components. This also keeps Parallax abreast of any possible failure trends should they occur. Given this the testing fee is not a given and we would inform you prior to charging the fee. Continued multiple product failures for the same issues may result in testing fees. Repairing your own product is always an option, as you might imagine that thought process is how Parallax was founded and we encourage this type of thinking. Depending on the repair attempt this could void any possibility for warranty recovery later so discretion is advised. 1/2 price unit exchanges are cost effective for production processes where down time is of importance or testing and self repair is not preferred. Always contact our tech support dept. before returning items for exchange or testing.

jaydag71

·Thanks guys (and girls?)! Its nice to get some positive and constructive input rather than what I might typically expect from many of the user forums I frequent (AVRchat!). It is also very refreshing to hear about the level of customer support services offered by Parallax ($10 fee or not!). For my fried BS2 I imagine that I will attempt an hour of work on it and if I cannot·get anywhere with it then chances are that I'll trade it in. After my last post I think I may have a good place to start. Since that post I have finished building my IDC2 and also built a cheapo JDM programmer to flash the firmware into the IDC2's PIC. I took the time to do these because of my fears in frying another stamp! With all the PIC samples I have lying around I should be able to fry a few without missing them. With the ICD2 I am going to design my own twist of the Ez-controller (PIC18F252 & everything else.) with the PIC socketed! I have always liked this board due to its ease of use- sort of like the BS2, except it was built for use with ASM and C.(but one can always get basic software too...)

·Anyways, I just wanted to cap the topic, so again thanks to all contributers, I definatly have a better view on my stamps! regards, jaydag71