zaboomafoo Posted June 17, 2008 Report Share Posted June 17, 2008 Hello,I would like to build a mios based simple control surface within the computer case. This computer will be a standalone hard disk recorder and this simple control surface will provide:- LCD display (time display, peaks, armed tracks, some other info)- transport buttons (5)- 3 buttons for arming/disarming the tracks (left-right, arm on/off)This all can be done with just a core and lcd. 8 buttons can be connected to AIN with no multiplexing.Now my questions:- can some other pins on the PIC be used for buttons (DIN)? It would be nice to add a few more buttons, but without adding a DIN module- is it safe to connect 5V and MIDI IN/OUT directly from the soundcard to core? Those would be permanently connected since everything will be fixed inside the PC case.Reards,Frank Quote Link to comment Share on other sites More sharing options...
/tilted/ Posted June 18, 2008 Report Share Posted June 18, 2008 - is it safe to connect 5V and MIDI IN/OUT directly from the soundcard to core? Those would be permanently connected since everything will be fixed inside the PC case.Yes, it should be safe to do this. I would recommend that you keep the filter caps on the board.Also, you'd be safer leaving the optocoupler on board than removing it, if you were thinking down those lines. Quote Link to comment Share on other sites More sharing options...
stryd_one Posted June 19, 2008 Report Share Posted June 19, 2008 - can some other pins on the PIC be used for buttons (DIN)? It would be nice to add a few more buttons, but without adding a DIN moduleYou can, yeh. The only tricky part is having the buttons notify mios when they are (de)pressed. Have a look at the J5 as DIN example code for hints. Why the aversion to DINx* modules? Quote Link to comment Share on other sites More sharing options...
zaboomafoo Posted June 19, 2008 Author Report Share Posted June 19, 2008 You can, yeh. The only tricky part is having the buttons notify mios when they are (de)pressed. Have a look at the J5 as DIN example code for hints. Why the aversion to DINx* modules?I would like to make this as simple as possible since it will be mounted inside a custom made computer case (3U rackmount), there will not be much space with all the other things that will go in. Using J5 as DIN gives me 8 inputs, and that is probably enough for this. It would be nice to add a few more, but not too critical.To reply to my post, I have this idea which I have to try (see the attached image). Basically two (or more) switches can be connected to a single pin on J5. 2nd switch would have a resistor connected to it in series, so when it is pressed it forms a voltage divider. so basically this would work as a "switching pot". each switch would give different voltage to the AIN and it could be decoded that way.I did something similar with the switches connected to the joystick port on a PC. Will give it a try with mios.Regards,FrankEDIT: I believe V+ and GND should be switched based on J5/DIN diagram.2_switches.GIF Quote Link to comment Share on other sites More sharing options...
/tilted/ Posted June 20, 2008 Report Share Posted June 20, 2008 yes, this should work, and be repeatable.coding will be slightly more envolved... but only slightly I would think. Quote Link to comment Share on other sites More sharing options...
stryd_one Posted June 20, 2008 Report Share Posted June 20, 2008 Seems a lot of trouble to spare 2 square inches... Especially in a 3RU case... But hey it's your box! Quote Link to comment Share on other sites More sharing options...
zaboomafoo Posted June 20, 2008 Author Report Share Posted June 20, 2008 Seems a lot of trouble to spare 2 square inches... Especially in a 3RU case... But hey it's your box!I know it sounds like that but 3U is actually not much. I need to put in there 3 sound cards, SCSI card, video card, breakout panel for 1/4 in and out (10 inputs, 10 outputs), probably a headphones amplifier too. real computer rack cases are large but they are too deep for music racks. this will be a custom made case about 13" deep so there isn't much space there. I cannot even fit the CD/DVD drive in, it will have to be external USB.I will post some pictures here once I have this going on (in few weeks). It will be a standalone HD recorder, running REAPER on w2k. Plan is to extend that to a digital mixer later on by adding something like midibox_lc on top of that.I think it is worth looking at this option. Adding one resistor per switch is less work than building a DIN board. Especially for somebody with not so great soldering skills like me :) . Programming is not an issue for me. As long as this is consistent in the values that come into A/D I can code a simple de-bouncing routine in there. problem would be if the buttons on the same circuit need to be pressed together, which is not the case here.Regards,Frank Quote Link to comment Share on other sites More sharing options...
stryd_one Posted June 20, 2008 Report Share Posted June 20, 2008 I'm pretty familiar with rackmount cases, I work in a building with many thousands of them :) If it's a custom case why not extend it by 2mm? Given that a DAW should use passive cooling, you'll want to make some more space in there anyway. Quote Link to comment Share on other sites More sharing options...
zaboomafoo Posted June 20, 2008 Author Report Share Posted June 20, 2008 I'm pretty familiar with rackmount cases, I work in a building with many thousands of them :) If it's a custom case why not extend it by 2mm? Given that a DAW should use passive cooling, you'll want to make some more space in there anyway.This being a DIY project I try to use things I already have around as much as I can. One of the things that limits the size of the case is the size of the rack that I am planing to use for this. 13" is max that can fit in there.I would rather put the headphones amplifier or balanced output driver in there instead of the DIN. I thought I would have plenty of space but just placing the motherboard (9x12) with soundcards, video card and scsi fills in most of the space. add power supply (1U) and HD - not much left in there.I see your point about the passive cooling, however I am building this for recording live performances so the noise of the PSU or SCSI drive is not a problem at all. I am more concerned about the vibrations. I had some problems recording loud performances with my roland HD recorder.This is going slightly off topic :) . I believe I got my answers, thanks everybody. I will post the results (once I have something) in case somebody is interested to build something like that.Regards,Frank Quote Link to comment Share on other sites More sharing options...
doc Posted June 20, 2008 Report Share Posted June 20, 2008 If you want to avoid trouble and if you don't want to program a lot:Use a DIN! You can also use a SMD 74HC165 if space is really an issue. greetsDoc Quote Link to comment Share on other sites More sharing options...
zaboomafoo Posted July 3, 2008 Author Report Share Posted July 3, 2008 I prefer programming over soldering (at least I am a bit better in that) :)I am working on this project slowly, almost in working condition. will post some pictures soon.Regards,Frank Quote Link to comment Share on other sites More sharing options...
/tilted/ Posted July 4, 2008 Report Share Posted July 4, 2008 If you are concerned about vibrations, there are a couple of options (off the top of my head).1) Replace any HDDs with solid state versions, be they Flash (slow-ish) of SSDs (expensive-very).2) Mount HDDs with rubber grommets around the mounting bolts. This means drilling out the mounting hole on the chassis slightly to accomodate the grommet, then pass the 3mm mounting bolt through the grommet. you may need to experiment with grommet sizes. This should dampen the type of vibrations you are likely to encounter at a live gig.Of course, If someone kicks your computer while you are recording, a grommet wont help much, but that's up to you to stop them!About a 2-3mm thickness grommet (where by thickness, I mean (outside diameter - inside diameter) / 2) should be enough to dampen the huge LF you'll get at a live gig. Quote Link to comment Share on other sites More sharing options...
zaboomafoo Posted July 4, 2008 Author Report Share Posted July 4, 2008 If you are concerned about vibrations, there are a couple of options (off the top of my head)....2) Mount HDDs with rubber grommets around the mounting bolts. This means drilling out the mounting hole on the chassis slightly to accomodate the grommet, then pass the 3mm mounting bolt through the grommet. you may need to experiment with grommet sizes. This should dampen the type of vibrations you are likely to encounter at a live gig.That is a good idea. I was thinking about something like that. Any (reliable) solid state solution would be very expensive and I am not even sure if there are any currently in 40+G size.It would also help if I mount the computer into one of those shock mount rack cases.Regards,Frank Quote Link to comment Share on other sites More sharing options...
/tilted/ Posted July 5, 2008 Report Share Posted July 5, 2008 It can't hurt to mount the whole deal into a shock mount case, but your main weak point will always be the HDD, as it is the only vital component with moving parts *unless you count the fan...SSDs are available on eBay, but it's still early days for the technology, and they haven't really caught up to the mechanical hard drives in terms of bytes per buck. On ebay they are starting at around US$180/32GB and US$300/64GB for "low cost" units.Offtopic: in the same seach results, I found a second-hand 8" floppy drive for US$250!"Jesus!! Why?" I hear you say... because it's from a Solid State Logic automation system. That right folks, an SSL. Quote Link to comment Share on other sites More sharing options...
stryd_one Posted July 5, 2008 Report Share Posted July 5, 2008 What happened to that device that had slots for standard SDRAM and an IDE interface? Quote Link to comment Share on other sites More sharing options...
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