Troubleshooting FAQ for newbies

[asbak]

Here are a couple of my experiences so far which may or may not be of benefit to other beginners. Much of the infos are already contained in the troubleshooting docs / forum but some of this may be useful to newbies who haven't had step-by-step experience in what to expect during the construction phase and are a bit overwhelmed by the amount of reading and searching.

NOTE: - there may be mistakes in some of the info so please feel free to correct them where you see it.

Case design

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To simplify the case design and save time, I opted to buy an aluminium DJ turntable flightcase and install the components inside. The front panel was made from 4mm acrylic plastic which is relatively easy to drill and machine at home with basic tools. I bolted a section of angled aluminium to the panel running through the middle from the left side to the right side to give it support and prevent flexing. The panel rests on brackets which were bolted to the inside of the case and makes for a reasonably rigid design. Afterward a thin aluminium sheet was stuck to the acrylic for a metallic look / feel. (Maybe this wasn't so clever because it meant having to cut out the same holes / slots again. Would have been better if everything were done at the same time). I fitted a piece of board to the bottom inside of the case to mount the components on with plain old self tapping wood screws.

All the machining was done by electric drill, metal hacksaw blade, jigsaw (don't use on the acrylic because it only melts) and metal files. It took a long time to complete and in retrospect you may want to do yourself a few favours by:

1 - Buying / borrowing / using some kind of a rotary tool & necessary attachments (probably one which can do around 33000 rpm, the cheaper models may be a bit slow) WEAR PROTECTIVE GLASSES!

2 - Avoid using square / rectangular switches (especially on a 64 switch project) by using round ones. Drilling a hole is easy, having to hand file / file 64 squares was not!!  ;D

I designed the front panel with Schaeffer's software. The angled aluminium that was added to the middle section was very useful to cable tie all the ribbon cables from the LCD, pots and switches to which prevents cable movement that would eventually have broken the connections. Make sure your cabling is neat and atttached securely and have spaces on the panel allocated for it to go. If possible, it may also be a good idea to mount the AIN's and DIN's to the bottom of the front panel though I only realised this after already opting for mounting them in the case.

For connectors on your modules you may want to avoid using SIL headers and rather use "multipole pcb connectors" such as those shown here:

http://www.rapidelectronics.co.uk/rkmain.asp?PAGEID=80008&CTL_CAT_CODE=30215

DIL cable connectors & sockets may also be useful for connecting DIN's & AIN's depending on your particular layout.

Although it doesn't seem to plague me, it would also be a good idea to position your transformer and internal AC powerleads as far out of the way of the AIN's as possible to avoid interference. Alternatively, use an external powersupply / wallwart but make sure it can deliver a enough current. The ones on eBay are often 300mA which I believe are too weak, especially if you plan on using your LCD's backlight and using LED's for the DOUT module.

Soldering

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Get a decent soldering iron which delivers a reasonable amount of heat with a smallish tip. I made the mistake of using a large cheap & cold piece of junk. I also used poor quality solder with too high lead content. Clean & prepare surfaces to be soldered with alcohol (don't get any on your hands because the methanol is poisonous and is absorbed through the skin) . Try not to touch surfaces about to be soldered because fingerprints leave oil residue.

Testing

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1 - buy a cheap multimeter (if you don't already own one)

2 - check the troubleshooting pages and pdf's on http://www.ucapps.de/ and test that your core module's values are as expected.

3 - Don't perform a final assembly of the entire project, test every module first as much as possible before continuing because there are bound to be problems with poorly soldered joints, wiring mistakes etc.

I'd recommend you start with the core module. Check the troubleshooting pages and test the circuit. If it seems OK, plug in the PIC and test again. Then attach the MIDI In & Out connectors & powersupply.

To upload MIOS:

1 - Make sure the core is NOT powered up.

2 - Make sure MIDI In & Out cables are connected correctly to your computer interface

3 - Load MIOS Studio on your PC / MAC / Linux box / whatever works for you

4 - Set up MIOS Studio Ports as per the instructions

5 - Unzip MIOS v1.8 and locate the HEX file

6 - In MIOS Studio, select this HEX file and set it to await an upload request from the device and press start. (MIOS must be uploaded within 2 sec's of the core being powered on)

7 - Power up the Core module, the upload should start. (Use input / output monitoring windows in MIOS studio to monitor this)

8 - You should see feedback confirming a succesful upload.

Upload the application you intend to use:

MIOS is the OS, now you'll need to upload the app example Midibox 64 or Midibox 64E. You can use the same method as described above, but use the HEX from the application instead of MIOS.

AIN Messages

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On the Midibox 64, once the app has been uploaded you should see loads of random analog input controller events in your monitor windows because the analog inputs aren't clamped to ground. This is normal. Once all the pots are attached to the AIN module/s and the AIN module/s are attached to the core, these random events should stop.

If some messages persist, it means that one or more of the pots PIN2 is not properly attached to the AIN module or maybe the AIN module is not properly attached to the core.

BTW, if you experience one or two "dead" pots which don't generate any controller info (althought there are no random events) this means that all the PIN 2's are attached but you have a problem with either PIN 1 or 3. Check the soldering.

LCD

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Once the AIN's behave as expected, you may as well attach the LCD. Initially expect to see a row of black bars on the first line. (During start up and also if MIOS hasn't been installed on the PIC)

Once MIOS has been installed, the display should read "Ready".

Once the MB64 application has been been installed, it will display a copyright message from Thorsten and then present a set of menus specific to the app.

LCD problems I have encountered

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1 - Wiring incorrect - try to get a datasheet before buying the LCD.

2 - backlight seems to have drawn too much current which reset the PIC and caused display anomalies.

Solutions

First, disconnect the LCD backlight to simplify troubleshooting.

Then, disconnect D7, D6, D5 etc. and experiment by disconnecting wires until the PIC stops resetting. In my case the powersupply / powercircuit was probably too weak to drive the modules and the LCD backlight. Problem solved by using a seperate power supply to power the LCD backlight.

DIN problems I'm encountering

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One of the DIN's is producing random on (127) events. There could be an issue with an incorrectly wired encoder / DIN wiring, Moebius has made some suggestions reg. this in the troubleshooting section. Wild_Weasel has also suggested checking for bad resistors with an ohmmeter / multimeter.

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To all the other posters, please feel free to add your experiences / tips here, what problems you encountered and how you solved them. This should help to eliminate repeated questions about typical issues facing the prospective constructor.

[Twin-X]

Dear Asbak,

This is a wonderfull tutorial and initiative.

However we have a wiki in progress we use that as a faq and tutorial. I certainly hope when it is available to the public you can contribute to it the same way you did here.

Regards,

Jeffry

[asbak]

Thank you Mr Twin-X.  :)

That's about the extent of my limited knowledge up to this point so please feel free to copy and paste any useful looking bits into the upcoming Wiki.

Best Regards

Hugo

As an afterthought, Moebius located an application that maps MIDI data to keyboard strokes called MIDI Translator 1.4 [http://www.bome.com/midi/translator/] which should enable one to use a MB64 type controller as a poor man's Mackie LC / Midibox LC. This could be useful for people wanting to use their MB64 for video-editing with programs such as Virtualdub etc. but since my MB64 isn't 100% operational yet I haven't had the opportunity to evaluate this.

[Jidis]

Yes,

Congratulations on a job well done Hugo!

Makes me feel guilty about not yet having typed up some similar stuff Smash requested quite a while back. :-[

He mentioned that at the point where you're just getting started, it's probably a good time to make note of any confusing areas you might hit, as other newbies may share the same experience. I had a whole long list scribbled up, but the more I learned and found in the forum,etc., the less sense the list suggestions made to me, so I was ashamed to offer any. 8)

I may still go through it and try to find some stuff which actually was confusing.

Take Care,

George

PS- On that keyboard note thing: I was coincidentally just thinking the other night, while carefully trying to store my Oberheim DX, how so many of those old "non-velocity-sensitive" machines could not only be effectively triggered from a standard computer keyboard, but the original buttons often actually felt like keyboard keys. I remember a Linn VSTi or something, but it seems like a good standalone app, with an on-screen simulation, would be a lot of fun, as well as some basic "newbie friendly" instructions on how to scrap a keyboard for a cheap DIY controller. Seems there was also some small, old app ("Sweet Little Piano" or something), which did QWERTY to notes.

<EDIT> Re-reading your info on the keystrokes, I realized that I didn't actually know what the heck you, or myself, were talking about. ;D

I guess you're talking more about mapping MIDI into computer command key events.

BTW--- Anyone know what it takes to do a DIY PS2 merge or "pass-thru" circuit (or is it simpler than that)? Seems like those small add-on, numeric keypads would have to have that feature too.

[asbak]

Hi George

Yep it was mapping MIDI control events to keystrokes that I'm on about which would enable one to use a MB64 or similar to compliment a computer mouse & keyboard for a variety of software titles.

Best Regards

Hugo

[moebius]

Thank you Mr Twin-X.   :)

Heh - thanx to Jeffrey! (uh and Jidis too!)

That's about the extent of my limited knowledge up to this point so please feel free to copy and paste any useful looking bits into the upcoming Wiki.

Actually - this was discussed when changing thoughts about the new wiki. What you call "limited knowledge" is also a strength as it makes You learn these things - Things that "more knowledgeable" people might see as a minor technical issue [limited vision], you have to learn.

So - I'm glad you posted this here and I hope you'll be transferring it to the wiki too - remember it can be then edited to form more and more suitable version.

This is also a call for others, "blog" (or whatever) your progress, tell us what was "wrong" or hard to understand in the documentation. Also success stories in the troubleshooting with the symptoms and the cure are more than welcome.

Moebius/ Samppa

As an afterthought, Moebius located an application that maps MIDI data to keyboard strokes called MIDI Translator 1.4 [http://www.bome.com/midi/translator/] which should enable one to use a MB64 type controller as a poor man's Mackie LC / Midibox LC. This could be useful for people wanting to use their MB64 for video-editing with programs such as Virtualdub etc. but since my MB64 isn't 100% operational yet I haven't had the opportunity to evaluate this.

IF you're going to use it with some known application or otherwise - You could make presets for the Midi Translator and/or tutorial in using it to control Desktop applications thru midi.... or Am I already demanding too much from you  ;D - No hurry!

[asbak]

Of course yes Mr Moebius but I'll have to sort out the DIN problem, recompile the MB64 2.4 app for 62 switches + 1 encoder and rework the powersupply before I can actually start using it with a degree of confidence. Troubleshooting takes ages because all the circuits are soldered together and screwed into the case....... another mistake I won't be repeating. Use connectors next time, lol :D

[MEEF]

thanks for this post, it been quite useful for me just starting out. Just wish i'd read the soldering section before i started working on it  ::) oh well, thanks anyway, its really good to read stuff like this.

[TK.]

before it will be forgotten:

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