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BS2SX Not Sending Signal? — Parallax Forums

BS2SX Not Sending Signal?

ProgressProgress Posts: 11
edited 2011-09-17 18:00 in BASIC Stamp
Hello guys, I'm using a BS2SX. When I use it on the Stamps in Class board it works fine (sends the appropriate signal) however, I want to shrink the size of the setup so I put it on my own custom breadboard but for some reason the micro-controller no longer sends a signal (LED doesn't flash). I bought this voltage regulator and I have vss on the bs2sx connected to its ground and V_out connected to VDD on the board. Voltage across the wires reads 4.56 V on a voltmeter. What am I doing wrong? Can you guys help me figure out why it doesn't send a signal on my setup?

Oh and I'm trying to send a signal through pin 15 in case that matters. I've checked all my wires thoroughly, solder's all good and they're all in the right places.

Thanks in advance

Comments

  • Mike GreenMike Green Posts: 23,101
    edited 2011-09-11 20:38
    Well, if it doesn't work anymore, then something about your board is different from the board that you used for Stamps in Class when it did work as expected.

    How about generating a schematic from your wiring and posting that (not a schematic of what you think you have).

    Just as one example of what you're not telling us is that the datasheet for your regulator says that a minimum output capacitor of 22uF must be provided or the regulator may not work properly. In fact, an output voltage of 4.56V is way too low for normal operation of the regulator and suggests that something is wrong there. If, by 4.56V, you mean the signal wires (pin 15 and Vss), that's probably correct. That would be a high logic level. A low logic level is on the order of 0.5V.
  • ProgressProgress Posts: 11
    edited 2011-09-11 22:15
    Ah I didn't realize the capacitor was required. I'll try the setup with a capacitor at both ends and let you know if that solves the problem. For the voltage what I meant was the voltage across VSS and VDD of the micrcontroller. Anyhow here's the schematic for my setup s9LD9.jpg.

    Thanks
  • Mike GreenMike Green Posts: 23,101
    edited 2011-09-11 22:42
    The layout looks ok. One question ... Is there some reason why you didn't use the built-in regulator on the BS2sx? That would make your setup even smaller and avoid the need for the 22+uF capacitor.
  • ProgressProgress Posts: 11
    edited 2011-09-11 22:57
    Well to be honest when I ordered the voltage regulator I didn't realize there was a built in regulator and now I guess it's just to be safe. But if I'm going to have to buy capacitors and stuff I think I might just hook up the battery (2 cell LiPo = 7.4V) straight to the micro-controller via Vin (#24).

    One really noob question though (sorry I'm relatively new to this stuff): the LED's ground would just go to the micro controller's VSS correct?
  • Chris SavageChris Savage Parallax Engineering Posts: 14,406
    edited 2011-09-11 23:18
    Correct, all connections should have a common ground.
  • ProgressProgress Posts: 11
    edited 2011-09-12 14:48
    I connected the battery straight to Vin / Vss and the voltage across those 2 reads 8.25V but voltage across Vdd and Vss reads .25 volts...Is there a command I need to have in my code to set Vdd to output, or do I need to put some capacitors / resistors somewhere?
  • Mike GreenMike Green Posts: 23,101
    edited 2011-09-12 16:14
    You only need to connect Vin to a source of +6-9VDC and Vss to the battery -. Vdd is connected internally to the output of the regulator and there are capacitors on the module for the regulator used. Something is wrong if Vdd is only 0.25V.
  • ProgressProgress Posts: 11
    edited 2011-09-12 17:14
    Could there be something wrong with my microcontroller (just the Vdd switch / internal regulator)? Is there any way for me to drive the Vdd into output? Anyhow, here's a picture of my wiring: yHqqJ.jpg
    To see if the microcontroller is sending signal or not I'm just placing an LED at the pins n seeing if it lights up. Once again, if I put it on the board of education LED lights up (signal sent) fine.
  • PJAllenPJAllen Banned Posts: 5,065
    edited 2011-09-13 05:47
    Why is this turning into such a big deal?

    trainwrk.JPG
    trainwrk.JPG
    472 x 453 - 38K
  • Chris SavageChris Savage Parallax Engineering Posts: 14,406
    edited 2011-09-14 11:05
    I think what PJ meant to say was, he hopes the circuit he attached helps you out. :innocent:
  • PJAllenPJAllen Banned Posts: 5,065
    edited 2011-09-14 17:00
    I presented the requisite, graphic information.
    It shows exactly what to do, that the member could make progress.

    You guys have been through 7-8 posts of verbal vaguery already and to no avail.
    If the member was familiar with jargon like "common ground" then he wouldn't be posing the questions/dilemma that he has.

    If I did not intend for it to help then I would not have posted it.
    It's unfortunate, but not surprising, that it was not presented earlier.

    [I wonder that, given his "Vin/Vss" note, he may have joined "Vin" to "Vss" to give all of the connections, by interpretation, a "common ground".]
  • ercoerco Posts: 20,256
    edited 2011-09-14 19:56
    Chris Savage wrote: »
    I think what PJ meant to say was, he hopes the circuit he attached helps you out. :innocent:

    What PJ is saying is... http://www.youtube.com/watch?v=_PdhKMMZbds&feature=player_detailpage#t=233s

    Gus & PJ don't mince words! :)
  • ProgressProgress Posts: 11
    edited 2011-09-17 18:00
    Thanks for the help guys. Turns out the micocontroller just wasn't fitting properly in my breadboard -.- So I'm going to try a new one and solder all the components together this time. I'll try out what PJ said and if things don't work I'll get back to you guys.

    P.S. I didn't connect Vin to Vss.

    Thanks Again.
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