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Possible Shorted Basic Stamp 2 — Parallax Forums

Possible Shorted Basic Stamp 2

MooneyguyMooneyguy Posts: 77
edited 2014-10-08 08:29 in BASIC Stamp
I may have inadvertently shorted my Basic Stamp 2 board from the back side and would like to know if there is a trouble shooting document available or else what measurements I should perform to determine if the board is good or bad. I had a working bread board made, then went outside to demonstrate it in the back yard and put it on a glass table. I started it up and to make room for my mouse, I pushed it to the edge of the table which has a frame made of old painted aluminum. The bottom of the board scraped accross the old painted aluminum frame. Then assembly then stopped working. When I unplug and plug in the unit with the USB, I get the USB lights to blink like normal but my yellow and green LEDs which are hooked to P11 and P14 now blink together and then stop blinking all together. The LEDs are only supposed to blink one at a time and then stop to let the other one start blinking. The unit I am controlling with the Stamp 2 still works fine. The board can still communicate with the computer. What are the trouble shooting steps I should go throught to see if the Basic Stamp 2 is good or bad? If P11 and P15 are bad, can P 8 and P 10 still be good or is the entire unit bad? I just got in a hurry to get the device hooked up and ended up doing something dumb along the way I am afraid.

Comments

  • Mike GreenMike Green Posts: 23,101
    edited 2012-01-23 15:27
    There's no troubleshooting document. The Stamp is pretty robust, but direct shorts are tough to protect against. First of all, can you write a program and download it to the Stamp? If so, most of it should be OK. Individual I/O pins could be burnt out. The way you test them would be to write a program that makes pin 0 high for 1 second, then low for 1 second, then repeats. You hook up a red LED to pin 0 with its current limiting resistor to Vdd and a green LED, also to pin 0, with its current limiting resistor to ground and see if pin 0 works. You repeat the whole thing for pin 1, then pin 2 and so on up to pin 15. At this point you know what each of the I/O pins is capable of doing. First the red LED should light for 1 second, then the green LED should light for 1 second, then repeat. 470 Ohm resistors would work for current limiting.
  • MooneyguyMooneyguy Posts: 77
    edited 2012-01-23 16:56
    Thanks Mike, I will give it a try for sure.
  • ercoerco Posts: 20,257
    edited 2012-01-23 17:11
    See Tracy Allen's ingenious test at http://forums.parallax.com/showthread.php?124744-Stamp-BS2-Testing&p=930555&viewfull=1#post930555
  • Paul RomskyPaul Romsky Posts: 66
    edited 2012-01-24 18:37
    Mooneyguy,

    Here is a program that I wrote last month. I had a bunch of old PStamps that I had blown some I/O but I could not remember which ones were blown.

    This program will test all the IO on any BS2 series PStamp. It checks VOH (Output High Voltage), VOL (Output Low Voltage), VIH (Input High Voltage) and VIL (Input Low Voltage). It then checks the Reset function, and then the Brownout Detector. After all tests are finished, the results are displayed and stored in EEPROM. You can even plug the PStamp in years later and see the results from the last test (and not have to re-run the test!). This way you can instantly see which I/O (if any) are bad so you can determine if you can use the device in your design. If all the tests PASS, then your PStamp is pretty much good to go.

    I will make changes in time. I will also make a BS1 version.

    Paul
    bs2
    bs2
    BS2_Test_V1_0.bs2
    7K
  • bsnutbsnut Posts: 521
    edited 2012-01-25 00:22
    That's a cool program that you did Paul and thanks for posting.
  • Paul RomskyPaul Romsky Posts: 66
    edited 2012-01-26 09:47
    bsnut,

    Thanks for the complement.

    Maybe you can put your "spin" on it for the Propeller. I have not yet explored the Propeller but I have started to write some code and to make up some libraries so that when I do "spin" up on it I will be ready.

    Paul
  • MooneyguyMooneyguy Posts: 77
    edited 2012-02-12 16:46
    Thanks Paul for the program. I will give it a try. Sorry it took so long for me to get back to the post.

    Mark
  • bsnutbsnut Posts: 521
    edited 2012-02-12 21:31
    Paul Romsky wrote: »
    bsnut,

    Maybe you can put your "spin" on it for the Propeller. I have not yet explored the Propeller but I have started to write some code and to make up some libraries so that when I do "spin" up on it I will be ready.

    Paul
    @Paul

    I will put my spinning touch to it.

    It's a good idea for you to make your own libraries too, since the Propeller has it's own libraries already preloaded in the Spin Tool.
  • ercoerco Posts: 20,257
    edited 2014-10-07 16:06
    I just found this old thread, but I enjoy sharing the genius of Parallax guru Tracy Allen at every opportunity. A zero-hardware, software-only Stamp test!

    http://forums.parallax.com/showthread.php/124744-Stamp-BS2-Testing?p=930555&viewfull=1#post930555
  • Chris SavageChris Savage Parallax Engineering Posts: 14,406
    edited 2014-10-08 08:29
    The following link points to the article I published in June 2014 Nuts and Volts showing how to build the official BASIC Stamp testers we use at Parallax.

    http://www.savagecircuits.com/stamptester
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