SX trouble

Rickvan · 2007-02-13 18:05

Several students in my program have purchased clone bots with BS2sx chips...when we assembled them, we all have the same trouble...the stamp editor doesn't see the stamp...it returns a "yes" to loopback and echo...
All of the voltage checks are good on the board, and several of us have the same problem...
Is it possible that the resonator is causing us grief (50mHz), or is there some way we can rule this out?

Chris Savage · 2007-02-13 20:17

Hello,

This thread is being moved from the SX Forum to the BASIC Stamp Forum.· What version of the BASIC Stamp Editor are you using? V2.2.6 is the latest.

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Chris Savage
Parallax Tech Support

Mike Green · 2007-02-13 20:25

Make sure you have the proper drivers in your PC if you're using a USB to serial converter. Some USB to serial converters don't work properly for downloading programs (some of the control lines aren't implemented properly). If you're using a standard serial port, make sure the cable is working. Try substituting another one.

You may need to provide more information about what you have including a schematic. There may be a power/noise problem. Although it's possible there is a faulty resonator, it would be unlikely to have several fail. Most likely it's a power or wiring problem. The voltages may look ok on a meter, but there may be noise pulses or other transients.

Rickvan · 2007-02-13 20:38

Thanks for your input....
the schematic is at : http://www.budgetbot.com/downloads/CBAMB_Sch.pdf

seems straightforward, and we all have the same problem. We have tried updated software, new cables, USB to Serial.....
no luck for any of us.
any input is very welcome.
Rick

Mike Green · 2007-02-13 20:43

The schematic says that the chip is a Stamp BS2e, not a BS2sx. If that's the case, the editor will not find a BS2sx, but should find a BS2e. They're different.

Chris Savage · 2007-02-13 20:51

Mike,

I don’t know if the schematic is correct at all…It shows a 24LC16 EEPROM which is incorrect for a BS2e or BS2sx…That EEPROM is for the stock BS2 only.

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Chris Savage
Parallax Tech Support

Rickvan · 2007-02-13 23:07

Thanks...
The board has a sx28ac/dp-g stamp, and a 24lc128 EEprom.

Tanj · 2007-02-14 01:08

I am in the same class as Rickvan, I have the same stamp, rom, board, etc. I tested out The BS2sx and my BS2e at home on my linux box...because some here thought it might be software. Well my BS2e works no problem using bstamp. I did get an error when I tried the BS2sx

tanj@zapper ~/bstamp $ bstamp_run hw.tok
Error: No BASIC Stamp identified!
Probably the stamp isn't connected, perhaps your stamp version isn't supported?
Try looking at the help, try 'bstamp_run -h' for more information.

the source I tokenized

'{$STAMP BS2sx}
'{$PBASIC 2.5}

DEBUG "Hello World!"

my guess from the error message is that the information for what kind of stamp is on the board is not getting through. Is this imformation in EEPROM? where is it? How is this information communicated to the software?

Mike Green · 2007-02-14 01:30

Do try 'bstamp_run -h'. I don't know which versions of the tokenizer support which Stamp models, but the help message may tell you.
There are versions 1.16 and 1.23 both available. Check to make sure which one you have. I suspect you want 1.23.

The Stamp interpreter that's programmed into the SX-28 knows which model it is and communicates with the PC shortly after the chip is reset (forced by the serial channel being opened and DTR pulsed) as part of the identification sequence.

The EEPROM just stores the byte codes for your program.

Tanj · 2007-02-14 01:57

tanj@zapper ~/bstamp $ bstamp_tokenize hw.bs2 hw.tok
PBASIC Tokenizer Library version 1.23

tanj@zapper ~/bstamp $ bstamp_run -h

Basic Stamp Linux Programmer / Debugger

This program is used to program and run a basic stamp.
Before it can be used, some simple setup must be done (see below).
For more information about the Basic Stamp, see http://www.parallax.com

This is a modified version of bstamp available at http://bstamp.sourceforge.net
Options:
        -h or -? : this help listing
        -v : the program version
        -a : about the program (brief history)
        -s : use stdin instead of INFILE.TOK
        alternately, to use stdin do not include any other arguments.

The basic stamp must be plugged into a local serial (COM) port.
Examples here use /dev/ttyS0 as the serial port,.
 but you may need to use something else (like /dev/ttyS1).
A symlink named 'bstamp' in /dev must point to the com port you wish to use.
This can be done with 'ln -s /dev/ttyS0 /dev/bstamp'.
If the serial port doesn't work, you might try 'MAKEDEV /dev/ttyS0'
You may need to be root to accomplish this, try 'su' to become root.
When done with MAKEDEV and creating the symlink, type exit.

You must include a tokenized program when calling this program.
First run 'bstamp_tokenize INFILE.TXT OUTFILE.TOK' to make the tokenized program.
Next run 'cat INFILE.TOK | bstamp_run'

Standard Usage: bstamp_run INFILE.TOK
 Or:
 cat INFILE.TOK | bstamp_run
 Or:
 cat INFILE.BS2 | bstamp_tokenizer | bstamp_run

Mike Green · 2007-02-14 02:08

Well, you're certainly using the right tokenizer version. That is the latest. Maybe someone with experience in Stamp use with Linux can comment. Consider starting a new thread with a title like "Linux and Stamp programming - Help!" and reference this thread.

Tanj · 2007-02-14 03:10

Well I have no problem doing the actual programming. I can also send the program to a stamp that can be found. (both in windows and linux) My problem is the same as Rickvan's. Loopback and Echo show up in the ID window but no Basic Stamp found.

This problem we are having is hardware (BS board itself) or in assembling it somewhere.
We are trying to discover the source of the hardware problem.

Thanks for the suggestions so far

Mike Green · 2007-02-14 03:20

Make sure you've tried the same "Hello World" compiled for both the BS2e and the BS2sx (change the $STAMP directive) on your clone bot. Maybe you think you have a BS2sx, but you really have a BS2e. The Loopback and Echo will show up if you have the "wrong" type of Stamp, but no Basic Stamp will be found because the Stamp programmer is looking for something different from what you actually have.

Bean · 2007-02-14 04:31

I don't know if this is the problem...
But I assume you have an SX chip that is programmed with the Stamp Firmware ?
If you are just using an SX28AC/DP that has not been program by Parallax, it will not work.
Just an idea

Bean.

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RobotWorkshop · 2007-02-14 04:57

I have a little robot that I built with one of the OEM BS2SX chips and after looking at that schematic you provided there is one thing that I saw which may be contributing to the issue you have. On my little robot I add a .1uf cap inline with pin 4 of the DB-9 connector. There is also a second .1uf cap from the side that goes to the MAX232 to ground. It may be that the your passing the loopback test due to the 4.7K resistor and that it can't find the Stamp because of the way the reset line is wired....

Hope this helps,

Robert

Mike Green · 2007-02-14 05:10

Robert is right. Look at the reset circuitry in the PBasic manual on page 26. It's for the serial version, but the same circuitry applies to the USB version. The problem is that the I/O drivers hold DTR true (low) when the serial channel is open. This keeps the Stamp in reset. The capacitors convert this high to low transition to a pulse which is what you want.

The capacitors were added a couple of years ago. I don't think they were needed under DOS and early Windows versions.

Rickvan · 2007-02-14 10:42

The chip is a genuine Parallax SX... and this board is commonly available from budgetbots....I dont understand how all of ours could be bad.....the design is not new, and it's safe to say that we're not the only ones to have purchased them.
Is there a way to ring out the chips to determine if they are faulty? They were shipped from US to Canada via the postal service....it is safe to assume that they were exposed to low level xrays....

Bean · 2007-02-14 14:13

Rickvan,
Not all Parallax SX chips have the basic interpreter in them.

Here is the one you want http://www.parallax.com/detail.asp?product_id=PBASIC2SX/P
Here is the one that won't work http://www.parallax.com/detail.asp?product_id=SX28AC/DP-G

Notice the difference in price. This has come up before, people just get the SX chip and think it will make a basic stamp.

Bean.

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Mike Green · 2007-02-14 14:25

Clearly, the adverts for the BOT indicate that you have the OEM SX with the interpreter pre-programmed into them. I would suggest that you try the reset capacitors. If you're concerned about the resonators, you will need to borrow an oscilloscope with a low capacitance probe to check for a signal on the resonator pins. This may still be difficult to test since too high a capacitance may prevent the oscillator from working. Given that all the units are exhibiting the problem, it's some kind of systematic error common to all the units and a parts failure is very unlikely on all of them.

Bean · 2007-02-14 14:32

Mike,
Sorry I didn't see the advert. Most likely not the problem then.

Bean.

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Cheap used 4-digit LED display with driver IC·www.hc4led.com

Low power SD Data Logger www.sddatalogger.com
SX-Video Display Modules www.sxvm.com
Stuff I'm selling on ebay http://search.ebay.com/_W0QQsassZhittconsultingQQhtZ-1

"USA Today has come out with a new survey - apparently, three out of every four people make up 75% of the population." - David Letterman

Tom Walker · 2007-02-14 14:37

How are you powering the programmer for these Stamps? Could this set of results occur if the power supply is insufficient? If I stretch, I can imagine a scenario where this might be the case...

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Rickvan · 2007-02-14 16:49

EUREKA!!!!
one of the students in the class assembled their kit, and it works perfectly...
He graciously agreed to let us swap some chips....his sx worked in a non-working board, and a non working chip didn't work in his....when we changed them back, all was well.
It looks like we have a lot of bad sx chips.....
Can they be re-flashed, or are they sinkers?

Mike Green · 2007-02-14 17:02

Sounds like you got a batch of bad chips from your vendor (budgetbot). You'll have to arrange with them to exchange the chips, then they would likely return them to Parallax with their purchase information for replacement. The question for Parallax is whether they're bad or somehow a batch of non-programmed chips got shipped out in place of some programmed ones (then how did that happen?) Another possibility is that budgetbot deals in both Stamp interpreter chips and unprogrammed SX chips and they got them mixed up. It's their business to sort that out.

Post Edited (Mike Green) : 2/14/2007 5:07:36 PM GMT

Rickvan · 2007-02-14 18:54

Thanks to everyone for their input.....
Nice to know there's a place to look......

SX trouble

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