Problems Getting the eb500 to talk to any BASIC Stamp other than BS2

Ray Hill

I've successfully communicated from 1 eb500 to another eb500 using BS2's. I'm now trying to use a BS2e and having no success.

I've swapped between a BS2, a BS2p40 and a BS2e.
I'm placing each Stamp on the breadboard so that I can leave my RS232, VSS, VDD, and eb500 jumpers in place. (Tying to make sure I'm not introducing a wiring mistake.)

When using the BS2 and the BS2e I use a Baudmode of 84 and for the BS2p I set Baudmode to 240.

I've sent various eb500 commands, like "get address". I get my expected "ACK", CR on the BS2, but not on the BS2e or BSp.
I've used SERIN 0, 84, [noparse][[/noparse]RxChar] and I never get a single Byte from the eb500.

Program listing attached

Any known problems or suggestions?

Ray

Mike Green

As long as you change the Baudmode constants and the $STAMP directive to match, there should be no problem with the eb500 (or any other similar device). I've swapped out Stamps of different models and just recompiled with a different $STAMP directive and everything worked fine with a variety of serially controlled peripherals. There must be something else about what you're doing.

Chris Savage

Ray,

In my haste to reply to your e-mail I quickly connected my BS2/BOE up with an EB500 and tested it with the “Get Address” code. As expected it worked. I then connected my BS2e and tried the same code. Surprised it didn’t work I grabbed the BS2p module and changed the baud rate parameter and tried it. Nothing. Now, the reason it didn’t work was apparent once the smoke started pouring from the module. Lesson to be learned…Never do anything in haste…I used one of our Wall Adapters which are unregulated currently…The output voltage driving only the BS2 and EB500 was too high and damaged the module by the time I tested the BS2e and BS2p. After replacing the EB500 and using a regulated P/S I was able to identify using all modules. I hope this helps…Take care.

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Chris Savage
Parallax Tech Support

Chris Savage

It just occurred to me some members may not realize…The EB500 power input cannot handle more than 12V max. Unregulated supplies typically exceed that when not loaded. Such was the case above.

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Chris Savage
Parallax Tech Support

Chris Savage

It just occurred to me some members may not realize…The EB500 power input cannot handle more than 12V max. Unregulated supplies typically exceed that when not loaded. Such was the case above.

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Chris Savage
Parallax Tech Support

Ray Hill

Chris & Mike,

Thnks for responses. It's obviously me or my breadboard set up. I'll keep looking.

Chris, sorry about your fried mods, but thanks for the look at other Stamps.

Ray

Chris Savage

Ray, no problem...In all my years of experience and caution working with electronics I have made an expensive mistake and posted it in the hopes it will make everyone aware of two things...Always be careful (for example I always erase a BASIC Stamp before using it for anything else)...Even when you are careful everyone once in awhile something is bound to happen to even the best of us. Take care.

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Chris Savage
Parallax Tech Support

KB3JJG

I wonder if Chris's next paycheck will be reduced by $69.95..heh

On a more serious note, a good tip about the unregulated supplies, I think this has caused me to fry a component or two and I never did know what happened.

Thanks chris!