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Never Give Up
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Please be positive and constructive with your questions and comments.

Never Give Up

by WingSpread on Wed Oct 24, 2007 2:54 pm

Last Spring I bought and built a MIDIsense board kit that worked up to the point of calibration: The red LED glows nicely, the green LED flickers in an avalanche of bits from the MIDIsense to the MIDI interface. MIDIsense software opens up, I select sensor #6, set Aftertouch note 64... and ... and the slider does NOT move. MIDI monitor shows a deluge of code pouring from MIDIsense. Apple's Audio/MIDI setup shows MIDIsense board connected to micro lite MIDI interface.

Meanwhile I have worked on other Ada projects learning about micro-controllers, etc.

Tried MIDIsense again today - no change. Didn't mellow over Summer.

My system:
PowerMac G5 PPC dual processor tower;
MacOSX v. 4.10
MOTU micro lite 5X5 MIDI interface (reputed to be solid, fine with my keyboards)
MIDIsense software v1.1
Tried numerous resistor values for R106
Power supply 12 Volt DC, positive center tip (brand new from Sweetwater Sound, works fine with M-Audio Axiom 25 controller, aslo tried batteries)
Metered resistance at different light levels on photocell, seems perfect
Four white dip switches on MIDIsense board all set to OFF (like your picture)

Now, this sounds like pilot error, but my very experienced friendly electronics Guru built his own 'MIDIsense' using parts he had, and obtained the same results. (Late model Dell high end computer) He thinks it's a surfeit of output from the MIDIsense. Too much of a good thing.

Hope someone can help, explain how to fix or why it cannot be?

WingSpread
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by adafruit on Wed Oct 24, 2007 4:43 pm

did you calibrate the sensor? does the raw data change? you may want to also take a photo of the finished board since it could be something else.

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Never Give Up

by WingSpread on Wed Oct 24, 2007 5:02 pm

Thanks for your quick response. Sadly, no, I've never been able to calibrate.

I'll take photos; how should I send them?
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by adafruit on Wed Oct 24, 2007 5:30 pm

what happens when you press Calibrate?

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by WingSpread on Thu Oct 25, 2007 1:03 pm

[img][img]/Users/pa/Pictures/IMG_0305.JPG[/img][img]/Users/pa/Pictures/IMG_0309.JPG[/img]/Users/pa/Pictures/IMG_0311.JPG[/img]


Here are three photos.

As you can (I hope) see, when I press calibrate and cover the photocell the slider in the small calibrate window moves to the left to about 518. That feels like it's working correctly.

But in the larger MIDIsense window slider #6 is passive. I can move it back and forth with my mouse cursor and it just lies there wherever I leave it. Other wise it doesn't do anything at all.
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Posting photos

by WingSpread on Wed Oct 31, 2007 11:34 am

I'm trying to post some photos where you can see them, LadyAda.
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by adafruit on Wed Oct 31, 2007 3:52 pm

ok let me know when they are up and post a link here thanks

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by WingSpread on Wed Oct 31, 2007 4:41 pm

This ought to do it. Photos of MIDIsense board and screenshot:

http://www.flickr.com/photos/8098352@N02/

Thanks
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New photo MIDIsense - solder side up

by WingSpread on Fri Nov 02, 2007 11:11 am

LadyAda here is the reverse side of my MIDIsense in all its soldered glory.

http://www.flickr.com/photos/8098352@N02/?saved=1
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by adafruit on Fri Nov 02, 2007 11:25 am

why isnt R106 soldered in?

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by WingSpread on Fri Nov 02, 2007 11:30 am

Ah, was trying various values of resister per example in MIDIsense tutorial.
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by adafruit on Fri Nov 02, 2007 11:52 am

hmm. why dont you put the sensor in the #5 slot since it has the 10K resistor soldered in?

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by WingSpread on Fri Nov 02, 2007 1:48 pm

OK, thanks, LadyAda, I tried putting the photocell into sensor #5 location and checked it out as has been done bunches of times before.

Same result almost exactly: The large #5 slider does nothing, not even turns blue, and the small calibration slider moves from right to left - to 522 instead of 518.

I guess the good thing about all this is its extreme consistency.

When I built MIDIsense last May, or so, my soldering skills were pretty tenuous; as you can see I soldered, de-soldered and re-soldered the socket for the main microprocessor. Don't remember whether the chip was in the socket at the time. Also, I checked the board for continuity with all the ICs in their sockets. One and/or both of these activities may have caused a problem(s).

When electronics "Guru" turned up with precisely the same outcomes on his home baked MIDIsense we both concluded there must be a problem with the MIDIsense software and so decided to wait for an update.

Guru is out of town and won't be available to talk about this for weeks. You've been good about helping me with this and I don't want to exploit your patience further.

When he comes back he can help me download the MIDIsense firmware from your site and ensure that the micro-controller is properly re-programmed. I'm thinking that maybe I corrupted the programming of my chip and that in all the jiggerypokery to transfer files to his computer from mine maybe he got a corrupted version of MIDIsense firmware.

I'll console myself with the other Ada projects I have yet to build.

Thanks again
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by adafruit on Fri Nov 02, 2007 4:06 pm

hmmm
do you have a multimeter or scope handy?
can you poke to see what the output from the opamp is for sensor #5 it should be pin 1? does the voltage range from 0 to something like 3V?

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by WingSpread on Fri Nov 02, 2007 5:11 pm

Measuring VDC from pin 1 on the little 8 pin opamp to ground side of sensor #5 I get 5.12 V DC.

Looking at the schematic, that seems like the right thing to do?
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Please be positive and constructive with your questions and comments.