debugging a soundless EMIC-2

PoundyPoundy Posts: 15
Hi folks, first time poster and somewhat not-a-prop-guy, sorry :tongue:

Got my EMIC2 the other day, sent Down Under, which was not from the "first batch" (ie it was only ordered a few days before the scheduled in-stock day after the first lot ran out). Anyway, all good, it arrived with no visible damage to the box, double bonus.

So here's my dilemma. I have the thing connected to a PC, with a CP2102 USB-serial connector. The EMIC2 comes up, initialises correctly, and I can talk to it using a terminal program (in my case, I am using TeraTerm). I can ask it to say things, I can ask it to play the demos, I can see and set properties correctly; all that works. The LED changes colour as expected (red when busy), and the serial response works as expected (":" returned once finished a command). But what doesn't work, is sound out. I have tried everything, commercial 8ohm speaker (old PC set that still seems to work), home brew speaker on a plug, but nothing seems to give me a sound out. Volume changes across the entire range, again nothing seems to work.

Now I don't know too much about the electronics of a speaker output, and I don't have a heap of tools (no o'scope) to help track down what might be going on, so I am hoping someone can give me some pointers, like watching voltage across a point with a DMM, or some other suggestions. One thing I am trying now (posting this before I try, hoping to also get some other suggestions to try in this diagnostic session) is a more capable input power supply, in case the CP2102 onboard 3v3 can't give enough current to the EMIC2, but I don't even know for sure if the behaviour that I see is reflective of that (Joe?)

here's hoping for some thoughts - thanks in advance !

Comments

  • 30 Comments sorted by Date Added Votes
  • Ron CzapalaRon Czapala Posts: 2,384
    edited September 2012 Vote Up0Vote Down
    Welcome to the forums!

    The datasheet 30016-Emic2TextToSpeech-v1.1.pdf says
    Power requirements: +5 VDC, 30 mA idle, 46-220 mA active (depending on speech parametersand output load)

    I suspect your voltage is too low. The audio output is only 300mw - try earphones...
  • PoundyPoundy Posts: 15
    edited September 2012 Vote Up0Vote Down
    Right, the results are in, the (strikeout)answer(/strikeout; yes I know that doesnt work :nerd: ) next problem is known.

    First though, have you ever noticed how when you change two things at once, you're invariably going to fix the problem, and then have a 50:50 chance of picking which one was right? :smile:

    So all my previous tests were with the board connected with .1" header wires straight from my CP2102 to the module and speaker connected via the socket. This time I decided I'd drop the module onto a breadboard so I could firstly supplement the power, and I had a breadboard mountable connector on a speaker so I plugged that in too.

    Fire up the terminal and tell it to play the demo. Yep, it worked first time. Bugger. No, no, I mean yay, don't I?

    Anyway, so I know this now works - unplug breadboard speaker and whack the plugged one back in, play demo, nada, not a sound. So I undo the power-boost and connect the breadboard speaker again and we're still working.

    So, it's the socket on the EMIC-2 board that isn't working. I've looked under a magnifying desklamp and head mounted magnifyer, can't see any obvious solder problems on the three connectors, but they don't have a lot of solder visible - it's still got a small fillet ul the side ofthe leg, so not something I immediately think is worth hitting with the soldering iron. Can anyone confirm what I should see resistance wise between what pads on the socket or some other way to see if I cna figure out if there's a short or something?

    Oh, and thanks for the suggestion @Ron. I had run it on 5v and 3v3 before with the same result, and have done so now and both seem to work fine - on my more permanent mounting solution I will make sure I juice it up from the 5v rail though just to be sure.
  • Roger LeeRoger Lee Posts: 338
    edited September 2012 Vote Up0Vote Down
    I would have never thought to run this directly from a PC. The description says it is for embedded systems.
    That means "Not a PC", right?
    Interesting to me that it works this way. Not that I'll be trying it, I still find it interesting.
    This is a signature line ---> Weirdness abounds ! ( I'm sure it will all work out )
  • PoundyPoundy Posts: 15
    edited September 2012 Vote Up0Vote Down
    It's just a serial device, and PCs have had COM ports for a few years now

    :cool:

    So yes, while it may say for embedded systems, this way I could eliminate the "unknowns" of micro controller serial ports etc. Now I know what was going on I'll connect to the micro like intended :thumb:

    So again, anyone who has insight into what I can test on the socket would be great !
  • PublisonPublison Posts: 9,666
    edited September 2012 Vote Up0Vote Down
    What kind of plug are you using, stereo or mono? If it's a stereo you might have the speaker connected to the Tip and Ring, and not the Tip and Sleeve (Ground).

    TRS Wiki here
    Infernal Machine
  • PoundyPoundy Posts: 15
    edited September 2012 Vote Up0Vote Down
    I've tried both, but the mono one certainly doesn't work...... the speaker I am now using was unsoldered from one of the mono plugs as well....
  • mindrobotsmindrobots Posts: 6,488
    edited September 2012 Vote Up0Vote Down
    If it's an issue with the socket or solder joints, I'm sure Parallax would be interested in hearing from you for QC purposes. If there is a component or possible mfg process issue, they will want to know so they can resolve it.
    MOV OUTA, PEACE <div>Rick </div><div>"I've stopped using programming languages with Garbage Collection, they keep deleting my source code!!"</div>
  • PublisonPublison Posts: 9,666
    edited September 2012 Vote Up0Vote Down
    The output connections are pretty easy to follow.

    Emic-2 Audio Out.JPG


    Check the connections from SP+ to the connector. C38 may be open.

    EDIT: SP- does NOT go to the connector.
    528 x 278 - 17K
    Infernal Machine
  • PoundyPoundy Posts: 15
    edited September 2012 Vote Up0Vote Down
    @publison, interesting, S- isn't connected to the connector from what you just showed me. Is there a "standard" that says whether the two spring loaded connectors in that diagram are the inner most or the outer most? Usually the tip is the positive, right, so the diagram would imply the two inner connections are the ones that should go to S+ pin, but I assume the capacitor across the line will block continuity testing while it's charged? So hard to confirm this I think :frown:
  • PublisonPublison Posts: 9,666
    edited September 2012 Vote Up0Vote Down
    Sorry, got called away for tornado warning. All are gone for now.

    The SP+ and SP- are differential output from the chip, and per the data sheet that's the normal mode of operation. The jack that Joe implemented should work also.

    The Tip and Ring are connected together on the EMIC-2 board, so a mono plug should work just fine.

    I would check continuity from the SP+ to C38, and then continuity from the other side of C38 to the Tip or Ring on your mono cable.

    BTW, did you try some powered speaker from the jack?
    Infernal Machine
  • PoundyPoundy Posts: 15
    edited September 2012 Vote Up0Vote Down
    no, no powered speakers were used; I've only ever connected passive devices to it. I have tried old PC speakers in enclosures, earbud headphones, and several speakers from Jaycar (our local commercial electronics hardware place, similar I guess to Radio Shack).

    I guess I could check connectivity, but tracking down C38 is virtually impossible, there's no silk marking on the bottom of the board, and it's a 4-layer board at least and all the routing is internal and therefore not visible on the surface under the soldermask.

    Edit: tornado warning - wow. Glad to hear things are ok.
  • PoundyPoundy Posts: 15
    edited September 2012 Vote Up0Vote Down
    mindrobots wrote: »
    If it's an issue with the socket or solder joints, I'm sure Parallax would be interested in hearing from you for QC purposes. If there is a component or possible mfg process issue, they will want to know so they can resolve it.
    I've put a support request through pointing to this thread too.... I just wanted thoughts first up but I managed to make more progress than I thought. A sample of 1 though, doesn't necessarily show a process issue, but might be a new test case they can consider.
  • mindrobotsmindrobots Posts: 6,488
    edited September 2012 Vote Up0Vote Down
    Granted, 1 is only 1. It seems like there were a couple other boards with bad solder joints on connectors in recent threads. As good as Parallax is about QC and their internal manufacturing, I imagine that wanted know about any suspects.
    MOV OUTA, PEACE <div>Rick </div><div>"I've stopped using programming languages with Garbage Collection, they keep deleting my source code!!"</div>
  • frank freedmanfrank freedman Posts: 1,264
    edited September 2012 Vote Up0Vote Down
    Poundy wrote: »

    So, it's the socket on the EMIC-2 board that isn't working. I've looked under a magnifying desklamp and head mounted magnifyer, can't see any obvious solder problems on the three connectors, but they don't have a lot of solder visible - it's still got a small fillet ul the side ofthe leg, so not something I immediately think is worth hitting with the soldering iron. Can anyone confirm what I should see resistance wise between what pads on the socket or some other way to see if I cna figure out if there's a short or something?

    .

    Is this a surface mounted socket? If so and you can not get to all pins on it with a soldering iron, maybe reflow with an air soldering tool.

    FF

    (added above with an edit, had not intended to reply but somehow hit the wrong key. Rather than leaving a blank "Duh??" .......)
    Ordnung ist das halbe Leben....
    Ich lebe in der anderen Hälfte
  • PoundyPoundy Posts: 15
    edited September 2012 Vote Up0Vote Down
    Is this a surface mounted socket? If so and you can not get to all pins on it with a soldering iron, maybe reflow with an air soldering tool.
    It is a surface mount socket but the flat legs are ~4mm long so are big enough to hit with a soldering iron, if that's what I should do..... not ready to try that just yet :innocent: (because I'm happy to give Parallax the opportunity to give direct debug tips if they would like)
  • PoundyPoundy Posts: 15
    edited September 2012 Vote Up0Vote Down
    The very helpful folks at Parallax are sending out a replacement - awesome service folks !
  • softconsoftcon Posts: 215
    edited September 2012 Vote Up0Vote Down
    I too am having trouble using the sp+/sp- for speaker output. When I plug in powered speakers, or earphones, it works just fine.
    However, using one of the button speakers from parallax, wiring sp+ and sp- to the matching pins on the button speaker only produces clicks, but no output of sound.
    I thought maybe this was a result of the basic stamp not having enough power left to power the speaker, but since it's powered by a 9-volt battery, this shouldn't be an issue.
    I do need to remove power from the emic2 while reprogramming the bs2, apparently the draw on the bs2 from the emic2 is too much to allow the programming to take place, but a simple unplugging of the 5V wire solves the problem.
    I'm not sure if the speaker pins (on the emic2) are incorrect or not, no way for me to tell, but if anyone else has tried this configuration (bs2/emic2/button speaker) and gotten it to work, I'd be interested in knowing how it worked out for you.
    If anyone has any suggestions on what I can try to make this work, I'd sure appreciate it, I was hoping to use the button speakers, to remove the need for earphone jacks being plugged and unplugged, but perhaps there's just not enough volume for the button speaker to pick up the output.
    I had my wife doublecheck the wiring for me before applying power (don't want to toast my shiny new emic2),, and (after changing locations of a couple of wires, off by one row) all was in order, but no sound out of the button speaker, but again, earphones/external speakers work just fine.
    Thanks for any suggestions.
    Blind programmer, and Parallax customer (bs2, quickstart, javelin stamp, spin stamp and more)
  • PoundyPoundy Posts: 15
    edited September 2012 Vote Up0Vote Down
    Hi Softcon,

    If you can get sound out of the socket, but not the SP+/SP- pins, then I actually suspect the speaker is the problem not the EMIC2. Do you have a 3.5mm plug you can solder the wires from the speaker onto, so you can eliminate the pins as the issue? Or an old set of headphones you can cut the wire on and splice&solder the speaker onto?

    The SP+/- wire polarity isn't super critical for a speaker to operate. It should still work if you have it reversed, although it likely won't be at an optimal volume. So there is little harm in reversing the connection from your speaker and seeing if that makes a difference to your experience.

    My last comment is that 9v batteies are really poor things to use, they don't have a very large current capacity which may be why you see issues, your battery may be sagging below a usable voltage during programming. I'd certainly try to eliminate that too.
  • softconsoftcon Posts: 215
    edited September 2012 Vote Up0Vote Down
    I know the speaker works, because before rewiring the board to handle the emic2, I had it playing dec the halls (took it as a demo to show a friend when we went visiting last month) so speaker is good.
    Unfortunately, 9-volt battery is the only power I have to use other than the usb port on the board (it's a bs2 homework board usb version) If someone can suggest another way to give it more power, I'm all for trying it out, but afaik, there's nothing else I can feed power into the board with in it's current configuration.
    I of course do have a bs2 module (compliments of the mystery bag) so I could move the code to that, but I'm not yet sure how to wire that one up, since I've not delved into it's documentation to see which pins are what.
    On the other hand, I do have a quickstart board, but my understanding is that they provide even less power outputs on their vin connection, so I don't think that would help in this case.
    Any other suggestions will of course be greatfully accepted.
    I was kind of figuring the output power might be too low to drive the speaker in combination with the emic2, but here's a question.
    Can I move the power wire over to the vin port on the bs2, and obtain more power output that way? Would that help?
    Blind programmer, and Parallax customer (bs2, quickstart, javelin stamp, spin stamp and more)
  • PoundyPoundy Posts: 15
    edited September 2012 Vote Up0Vote Down
    I still think it's worth proving, if you can, that the speaker works on EMIC2 on the socket, since you know the socket works. I have been assuming that this is an 8ohm speaker - I can't find a Parallax speaker with "button" in it's name. Is this the speaker you're talking about? http://www.parallax.com/StoreSearchResults/tabid/768/txtSearch/speaker/List/0/SortField/4/ProductID/106/Default.aspx

    If so, that's a Piezo, not a "real" speaker so isn't going to work.
  • softconsoftcon Posts: 215
    edited September 2012 Vote Up0Vote Down
    Ahh, got it. That is indeed the speaker in question. Good reason why it didn't work, sorry for the confusion. I'll find something else to use there. I did get a set of speakers fro the dollar store that are really cheap, cuting the cord, and stripping it and using that as a diect connection may work, I'll see what happens. Thanks for clearing that up for me, good reason why it was just clicking, expected behavior if it can't play those outputs.
    Blind programmer, and Parallax customer (bs2, quickstart, javelin stamp, spin stamp and more)
  • PoundyPoundy Posts: 15
    edited September 2012 Vote Up0Vote Down
    cutting the cord from the speaker wire should work fine ! Most speakers like that are 8ohm which will work fine. Good luck !
  • CircuitsoftCircuitsoft Posts: 996
    edited September 2012 Vote Up0Vote Down
    Publison wrote: »
    The Tip and Ring are connected together on the EMIC-2 board, so a mono plug should work just fine.
    No, no, no! Every mono plug I've seen shorts ring and sleeve together, so you must use a stereo plug.
  • PoundyPoundy Posts: 15
    edited October 2012 Vote Up0Vote Down
    Parallax sent through a replacement for me - worked first time. Great support!
  • PublisonPublison Posts: 9,666
    edited October 2012 Vote Up0Vote Down
    No, no, no! Every mono plug I've seen shorts ring and sleeve together, so you must use a stereo plug.

    Would't a short between Tip and Ring render the plug useless? I't only a two conductor plug.
    Infernal Machine
  • CircuitsoftCircuitsoft Posts: 996
    edited October 2012 Vote Up0Vote Down
    Every mono plug I've seen, the ring and sleeve are the same contact, while Tip and Ring are generally Left and Right respectively.

    So, if the board you're plugging into (like this one) short Tip and Ring together to make stereo, then a mono plug (where ring and sleeve are the same) will short the output to ground.
  • PoundyPoundy Posts: 15
    edited October 2012 Vote Up0Vote Down
    sigh - newbie problem here, anyone know how I trigger this to be "solved" now?
  • RDL2004RDL2004 Posts: 2,554
    edited October 2012 Vote Up0Vote Down
    Go to the first post in the thread, click "Edit Post", then "Go Advanced". On the next screen look for the drop down "pre-fix" menu thing and change to "Solved"
    - Rick
  • PoundyPoundy Posts: 15
    edited October 2012 Vote Up0Vote Down
    Wow, ok, done. Weird place to do it, but I guess I get it... somehow, perhaps :lol:

    thanks everyone for the chat !
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