Monday 25 July 2011

Slightly more organized

My work has been making unusually high intrusions into the more important aspects of life recently, with the pressures of moving to new premises and trips to The Netherlands and Italy in the last two weeks. Although little has been achieved in matters which might interest you, dear reader, I have at least been able to move slightly forward on the Virtual Organ (Blogs passim)...


Specifically, the organ has acquired another set of Hammond drawbars (giving me a full complement of 9 drawbars for each of the swell and great manuals), a dedicated PC and an old monitor.

This past weekend, I finally got round to transferring the main controller (in which a PIC16f873 reads all the drawbars and switches and sends their settings to the PC over MIDI) from a solderless breadboard to a couple of PCBs...


The main controller board still has a 16*2 display, which one day will move from the board to a visible position on the outer case of the organ. There is also a separate "decode" board, made to correct my own stupidity in not incorporating sufficient decoding on the drawbar interface boards (the action of which is described here), one of which is seen in the photo above.

Also visible in the photo are a couple of small boards which provide interface to assorted analog controls (at the moment, potentiometers for percussion and key-click level). These boards also interface to switches but this is a waste for simple "Boolean" controls - one day I'll use the matrix interface I've built into the new controller board to read the switch settings.

The photo below shows the organ in a corner of the shack, with the software running in the new small form factor PC I "won" on eBay just for this project.


The pedal-board "woodwork" needs completing - in fact the entire organ needs a new enclosure. Still - at least it is now working, playable and self-contained. Next task is to sort out the bug in the new PC which is making it very difficult to turn on (without apparently random resets, visits to "Safe Mode" etc). Perhaps I should have relied on traditional tone-wheel technology rather than a computer!

...-.- de m0xpd

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