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Is my bs2sx dead? — Parallax Forums

Is my bs2sx dead?

TintinTintin Posts: 37
edited 2006-08-14 23:20 in BASIC Stamp
I have an oem bs2sx board.· Unfourtunately, it can't be identified by my computer (I am using a regular serial connection
).· What I have noticed is that with the power applied, Loopback and echo fields are marked as "yes" while with the power off only loopback is marked as "yes". The version and device fields are empty.· This occurs whether or not the interpreter chip is inserted.

Is there a test that can be performed to check if the chip is dead? I have already verified that 5 volts are fed to it, but other than that, what can be done?

Thanks for the help,
Frank

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Comments

  • Chris SavageChris Savage Parallax Engineering Posts: 14,406
    edited 2006-08-13 02:50
    Frank,

    ·· What version of the BASIC Stamp Editor are you using?· If it's not 2.2.6 then please download the latest version from our website at the following link and try that.

    http://www.parallax.com/html_pages/downloads/software/software_basic_stamp.asp

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    Chris Savage
    Parallax Tech Support
    csavage@parallax.com
  • TintinTintin Posts: 37
    edited 2006-08-13 10:44
    Thanks, I will try that right away.
  • TintinTintin Posts: 37
    edited 2006-08-13 11:02
    Unfourtunately the problem remains, Can·the chip be defective from the start... It never worked.

    Any other insights?

    Thanks,

    Frank
  • LoopyBytelooseLoopyByteloose Posts: 12,537
    edited 2006-08-13 11:25
    Take a look at the COM report that appears right behind the message that says the BasicStamp is not present. If it says that the computer cannot find the COM port, it is a system problem.

    This is a very common startup problem as Windows and various firewall programs are less and less willing to provide automatic access to any port on a computer.

    Is your BS2sx dead? Highly unlikely unless you gave it a nice jolt of raw power.

    I just had my BS2p hooked up wrongly [noparse][[/noparse]no ground, the VSS was connected to RESET by error] and it seems to be just fine.

    Reverse polarity and significant overvoltage are the great destroyers on the power supply side.

    On the I/0, they can both do damage as well AND you have to limit the current to about 20ma. When in doubt, use a 220 ohm protective resistor on PINs 0-15.

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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
  • TintinTintin Posts: 37
    edited 2006-08-13 12:03
    Behind the text box that says no basic stamps found, the device field of the port status is blank and echo and loopback are marked as "yes".··

    Is it possible that the pinout of the bs2sx interpreter has changed since 2004 (when the board was purchased) causing this mal function?
    ·
  • Bruce BatesBruce Bates Posts: 3,045
    edited 2006-08-13 17:18
    Frank -

    No, the pinouts have not changed at all on the BS-2SX interpreter, to my knowledge.

    Has this BS-2SX OEM set-up ever worked, or is this first time you've tried to use it?

    Are you using a "straight through" (pin 1 to pin 1, etc) serial cable?

    Is this a desktop computer, or a laptop? Which operating system are you using?

    Are you using batteries for power, or an AC power adapter?

    Regards,

    Bruce Bates

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  • TintinTintin Posts: 37
    edited 2006-08-13 17:58
    Bruce, to answer your·questions:

    -This is the first time I have tried to use it (never worked before).
    -Cable is straight through.
    -Tried on both my laptop (win xp pro) and desktop (win xp home) with same results.
    -Tried batteries (9 V)·and AC supply (7.5 V, 60mA) --- Power was my first concern: I·measured 5.01 volts between Vdd and Vss directly on pins of the chip with·battery and 4.79 with adapter.

    Thanks for the reply,
    Frank
  • willthiswork89willthiswork89 Posts: 359
    edited 2006-08-13 19:16
    i guess i could just take it off your hands for you..... i know i know its a good deed but im just a nice guy! lol j/k... why dont you try to eliminate some of the problems... try using the serial wire with another device and ensure the serial port on the PC isnt damaged and still functions correctly, if it does then you know its either A. the Board or B the chip
  • LoopyBytelooseLoopyByteloose Posts: 12,537
    edited 2006-08-13 19:51
    Someone from Parallax should jump in.
    I still suspect there is an interface problem unless the chip was either assembled wrongly [noparse][[/noparse]can that be possible with an OEM chip?] or it is damaged 2nd hand goods.

    The interface of the serial port to the usual BasicStamp requires two small capacitors involved with the DTR line, nothing on the Rx or Tx. Those are on the OEM board under the 3 transistors.
    Also, you might have the transistors either wrongly positioned. [noparse][[/noparse]I get dyslexic when I look at a transistor].

    Can you turn off echo and loopback? Do you have pins 6 and 7 on the RS-232 DB-9 connected? I believe that is a requirement to tell the computer that a BasicStamp is plugged in.

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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

    Post Edited (Kramer) : 8/14/2006 12:32:30 PM GMT
  • allanlane5allanlane5 Posts: 3,815
    edited 2006-08-13 21:14
    And you DID buy the SX chip from parallax, pre-programmed with the PBasic environment, right? It's not some 'plain', off the shelf SX chip.
  • Chris SavageChris Savage Parallax Engineering Posts: 14,406
    edited 2006-08-13 21:41
    Tintin said...(trimmed)

    Unfourtunately the problem remains, Can·the chip be defective from the start... It never worked.

    Unlikely, these are all tested by us prior to shipping.· Still waiting to hear if you got the SX chip elsewhere, and I am also concerned that you got less than 4.8V when using the wall supply.· Was the output of that AC or DC?

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    Chris Savage
    Parallax Tech Support
    csavage@parallax.com
  • TintinTintin Posts: 37
    edited 2006-08-13 22:05
    Yes the chip is a parallax pre-programmed.·

    Pins 6 and 7 are indeed connected, caps are in for DTR, RX and TX are·floating and the transistors are correctly positioned (incidently, couldn't transistor manufacturers put a dot on the casing next to the emmiter pin; I always need to double check with transistors to make sure they are positioned correctly!).

    Loopback is·on when the board is connected and off otherwise.· Echo is on when the power is applied to the board.· This confirms RS-232·comm is ok.·

    I know the port on the computer side is functionning properly·because·I·can communicate·with my TI graphic calc.

    I have been checking all soldering joints, confirming connections with the OEM circuit diagram but still no positive results.·

    Thanks to all for the good info!·

    Frank
  • Chris SavageChris Savage Parallax Engineering Posts: 14,406
    edited 2006-08-14 00:10
    Frank,

    ·· You didn't reply about the power supply...Is it AC or DC output?

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    Chris Savage
    Parallax Tech Support
    csavage@parallax.com
  • TintinTintin Posts: 37
    edited 2006-08-14 02:52
    Sorry about that Chris; at the time of my last post I had not seen yours...

    The output of the·power supply·is a 7.5 Volt DC supply.· Could it be a problem that it has a max rating of 60 mA?· If so, could insufficient current have damaged·it?· The chip·was·ordered from a local distributor, but is still a·genuine parallax part.· I am still waiting for a response from them concerning my problem.· However, I was·optimistic about finding a solution other than a "dead chip".

    I·truely appreciate·this forum's·concern and help,

    Frank
  • LoopyBytelooseLoopyByteloose Posts: 12,537
    edited 2006-08-14 12:40
    60ma is a bit tight for the SX if that is your power source rating. I believe that it is the biggest power hog of all the BS products.
    I imagne that you would merely cause a voltage drop that would make the BS not operate, but damage needs excessive energy applied at a weak point. Seems you don't have that condition.

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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
  • Chris SavageChris Savage Parallax Engineering Posts: 14,406
    edited 2006-08-14 14:37
    Kramer is correct...The BS2sx consumes 60mA running...Add to that overheat of the regulator and you're maybe taxing such a weak supply.· 9V batteries are pretty weak too, but it would seem if you measured 5V at Vdd it should be working.· If I may ask, why did you replace the interpreter chip in the first place?· If it was because the module was damaged or not working, then perhaps there is another problem?

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    Chris Savage
    Parallax Tech Support
    csavage@parallax.com
  • RobotWorkshopRobotWorkshop Posts: 2,307
    edited 2006-08-14 15:05
    Are you using the pre-assembled OEM BS2SX board or are you just using the chip, EEPROM, and 50Mhz resonator on your own PCB?? That isn't clear from your post. If it is the SX stamp module is either the DIP format or OEM module then it should be fairly straightforward to get started. Both have an on board 5v voltage regulator so as long as you provide a good DC power source of at least 5v it should work. After reading a few posts I think the power sources you've been using are questionable and you should try something better. I've been using a BS2SX on a small robot which it powered by five Nicads at about 6v total.

    If you are building your own PCB then that opens up a whole bunch of other questions. I've done it on a protoboard using the individual OEM components and as long as you follow the schematic it works well.

    Good luck,

    Robert
  • TintinTintin Posts: 37
    edited 2006-08-14 22:34
    To clarify: The board·was·assembled from OEM components.· I will·proceed by replacing the sx chip and keep you all informed on how things turn out!

    Thanks for all the help,

    Frank
    ·
  • Chris SavageChris Savage Parallax Engineering Posts: 14,406
    edited 2006-08-14 23:20
    Frank,

    ·· That makes a difference...I thought you had a BS2-OEM and had recently replaced the interpreter on it.· You have a home-brew OEM unit though...

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    Chris Savage
    Parallax Tech Support
    csavage@parallax.com
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