lylehaze

Well.. I bought my PIC pre-programmed, so I never used the PICKit2 on my original core. But it's easy to see if you've got it right. If a PIC has been programmed with the bootloader, when it is powered on, it will send a SysEx request every couple seconds. The next step is to load MIOS.. after that it will send the SysEx upload request only once on powerup. Then you load your application. Actually the MIDI bootloader works GREAT. It is super-convenient to be able to load new code without removing the chip, or even digging your MIDI device out of the rack (or wherever you keep yours) I have done the last few (hundred) rewrites of MBMixer without ever pulling the mixer or opening the case. The "old" MIOS Studio required Java.. the new one does not. Make sure you know which one you have, and follow all the troubleshooting steps in the WIKI. You are not the first to have a few problems, there are steps listed there that can help you figure it out. I'm late for work. LyleHaze Oh, MAJOR "I forgot".. The ID of the chip MUST be set correctly.. and if you don't know what you want, set it to all ZEROS. I think it defaults to all FFs, and that won't do at all. Yes, you CAN easily set the ID from PICKit2.. I have changed it for someone else using mine.

There are a few considerations.. You mentioned that your PIC is running at 64 MHZ.. How did you manage that? What crystal is connected to your PIC, and what are your oscillator settings? If you really are running at 64 instead of 40 MHZ, then your baudrate will be over 50% too high. But if that's just what the chip is RATED, then a 10Mhz crystal and X4 PLL will work just fine! The PICKit2 is a great programmer, especially if you use MPLab, as I do. Most of the MBox crowd have moved to a GCC toolchain, with a free C compiler too, but I'm still stuck in MPLab myself. There's a great USB-MIDI interface called the "GM5".. just search this website to learn more. Good Luck, LyleHaze

As you wire this up, you should connect Vd on J1 with Vd on J2.. you can connect anything asking for +5 volts to either of these. You should connect the VS from each of J1,J2,J3, and J4 together. You may connect anything asking for ground to any of these. If it's a simple 3 terminal encoder, one pin should be VS, and the other two D0 and D1, but I cannot tell you which pin is which. If it works backwards, swap the D0 and D1 pins. If it is an "optical" encoder, it will also need a Vd connection, but you should have a datasheet to tell you all about it. Check the WIKI for more details, Have Fun! LyleHaze

I believe you'll find that a DOUT module will drive those outputs with a better response time. :) Have Fun, LyleHaze

Another option.. if you want to use those faders would be to use an op-amp to buffer each fader. Easy to work out, but you want "rail to rail" amps so you don't lose the top and bottom edges of the signal. Or have a op-amp supply that is above and below the fader range Have Fun, LyleHaze

You do not need to add any EEPROM.. it is already inside the PIC. As far as I can tell, MIOS does not use the EEPROM for anything. it DOES use the 8 bytes marked as "ID Locations" to designate the core ID, display and communications type, and IIC address. The correct values for those addresses can be worked out from the app at SmashTV's website. For the most common uses, the eight ID bytes should be set to zero. Have Fun, LyleHaze

Many of the "Noritake Itron" VFD displays (like the one in the video above) include characters that can be arranged to make a horizontal bar-graph display, without the need for "custom characters". I have a Left & Right growing from center type of level meter in the MBMixer software, even though it's not supported by all display types. It's written in PIC ASM.. available on request. LyleHaze

Welcome! Start Here Then let us know how it went! Have Fun, LyleHaze

No Midi?? WTF? Wrong Forum.. try "NOMIDIBox.org".. or maybe "WeDontNeedNoStinkingMIDI.com" They have a great article on making rhythm patterns by banging rocks together. :) But seriously.. there are very reliable ways to pitch bend without modifying the electronics. Google up on "Doppler Effect". You can change the pitch of your keyboard higher by moving it towards your listeners, or lower by moving it away from them. So you can work up a great solo riff, and for the big "pitch bend" climax just throw your Casio at the crowd. The faster you throw it, the higher the pitch bend will be! Hey, physics CAN be entertaining! :) Have Fun, LyleHaze

OK, so maybe I'm thinking about a different way to do this.. instead of hacking up the original electronics, how about building this as a midi controller? Set up your new stick to send 14 bit Pitch Wheel commands.. Add an extra smaller control to send RPN Messages to set the total pitch range, and leave an open channel or two for a Modulation Wheel if you want to add that later. You could do this all on an 8 bit core without any additional modules, once it's tested you could then build it into the Casio case or keep it separate, and as a bonus, you can test it all in advance before you build the first thing just by sending the appropriate MIDI commands for your PC to see how well the Casio handles it. This just seems easier than trying to reverse-engineer the Casio tuning system. :) Have Fun, LyleHaze

I don't know what the current status is.. We have talked about a re-design to make it all easier to build and more affordable, as the "stackpins" that I used in the last revision turned out to be a problem. The new design will look more like a normal board, but it will fit more PGAs per board, and use standard connectors. At least, that's the last I heard. It is still "actual", just not yet. I can tell you it works well, mine has been running every day for a long time.. it's the center of my entertainment system right now. And just in case you missed it, there's a java program for controlling a MIDI mixer over will control a MB-Mixer, or any Midi mixer, or most other midi gear if you take a few minutes to write an XML file that describes what you want. Thanks for your interest! LyleHaze

I hope you find it useful. It can be used for other things besides mixing, too. Midi start, stop, and continue buttons, for instance, Or a window full of icons that select different programs.. could make selecting instruments easy for young-uns. Or might be handy for selecting patches quickly from a guitar effects box.. Modern guitar effects are very powerful, but a lot of axe-men couldn't figure out how to manage program-changes to save their lives. If you give them big, colorful buttons that match what the preset sounds like, they'll actually get a lot more out of the effects boxes... or even a full board for tweaking the presets! :) I'd LOVE to see some sort of editor window for some of the SID toys people have around here.. I thought of putting one together but I have no SIDs toys to play with. But since it does NOT support SysEx, that will probably limit how deep it can go. But mostly I'm just glad I released it.. It has been a fun project, but I"m glad to be back in PIC ASM where I'm comfortable. I'm up to my neck in remote control codes right now, I'll be adjusting the mix with a remote control within a week or two. Have Fun! LyleHaze

OK, I'll take a short shot at explaining this. The center leg of the regulator is a ground reference. The output voltage is measured from this point, so it should be a stable ground reference. These linear regulators draw as much current as they deliver, and "burn off" the excess voltage as heat.. this is also done through the center pin. So if you have a (example) 7805 making + 5 volts at a half-amp, from a 9 volt input supply, you'll be taking in 9 volts at close to 1/2 amp at pin 1, and you'll be supplying 5 volts at about 1/2 amp at pin 3. The difference, 4 volts at a half amp, will be burned off as 2 watts of heat, and this current will pass through the center leg.. WHICH IS ALSO YOUR GROUND VOLTAGE REFERENCE.. Now, back to the big picture.. the current draw through this regulator will change with the load. As the current through the regulator changes, so will the current through your resistor. As that happens, the "voltage reference" center pin of your regulator will no longer be a steady voltage. In fact, it will move in voltage giving an accurate amp gauge of your circuit load. As it moves, the output voltage of your regulator will move too, since it's trying to stay 5 volts above that reference. So you have created a variable voltage that changes reliably with current draw. This is great if you need an ammeter, but really bad if you want a regulated voltage. Diodes have a (fairly steady) forward voltage drop, so this would be better. Best choice by far would be to use the right regulator for the job. They DO make 7809 regulators, although you would need to supply about 12 volts input for that to work reliably. The next choice would be to use a pair of 7805's to get ten volts. Use the output of the first one as the center pin of the second.. it's sloppy, but better than the resistors you have going now. I hope some of this made sense.. it's early, I just woke up. Have Fun, LyleHaze

Ouch! Nice catch Sparx. Using a resistor to offset a 7805 to another voltage is a bad idea.. as the load on the regulator changes, the current through the reference pin will too. So now your "reference" is shifting with the load, this will create a unbalanced load any way you look at it. This would get even worse if you're trying to reference the amp stages at half-voltage or something (which you are also doing) Change that to a "correct" regulator of the desired voltage. Wow, I missed that completely. I must be getting old or something. :)

OK, so there's some opportunities here. The schematic really helps, but the construction method also plays a part. I have no doubt that the power supply is carrying the noise across for you. And because you're using relays, you can completely eliminate that problem. Here's how: A relay, unlike a semiconductor, allows COMPLETE isolation between the control (coil) and the switches. There is no need to have a common ground between them. Get a separate power supply for your op-amps. DO NOT connect the digital power supply to the analog supply. not even the grounds. Let the digital supply drive the core, modules, and relay coils. Let the separate op-amp supply drive the signal stuff ONLY.. and shouldn't you be using a bi-polar supply for the op-amps? Once the supplies are separated, the only path left would be sloppy construction methods. Have Fun, LyleHaze

Thanks for the feedback! Seven days since I posted it, and yours is the first reply. I was beginning to wonder if anyone has tried it at all. There are a few plans for expansion, but I am not planning on adding any editing features.. Especially since this is my first java project, I want to keep the goals as simple as I can. I have found that just cutting and pasting from the examples given should be enough to get all but the very laziest people all that they need. It really is pretty simple to manually edit XML files. Once before the XML stuff was added I made a "custom" java window that added a LOT of EQ controls for another user.. that was kind of the idea for the XML support.. if you want more controls, just describe the info.. pick a knob image, a CC number, and where it appears in the strip.. it really is just that easy. I am willing to help with XML editing if anyone asks me. With a _little_ more effort editing images, anyone could change the look completely. Right now, I have set Java aside and returned to PIC ASM for the next few projects.. On the short and easy side, I need to make some changes to the MBMixer software. I need to remove the MB-Stor stuff, as I'm not using it much, and then add hardware and software to support the meter bridge.. I have everything I need on hand to complete that stuff. While I'm in there, I'll add channel mute support, as I included it in most of the XML Mixer examples anyway. Once that stuff is done, I need to build a IR remote receiver that emits MIDI code.. as we're using this in the living room right now, and my wife wants to use a remote instead of the local control or BCR or the XML Mixer window... The multiple input and output feature makes adding more control sources a breeze. The IR receiver WILL be a PIC project, but probably not based on MIOS. Getting back to your question.. I will be updating it to support audio meters, either single or stereo per channel strip, as soon as I have the hardware to test it. I'll also fix bugs or add simple features, but there's no plan for an editor, and it's not likely to be added, unless it becomes a commercial project and I'm getting paid for it. :) Thanks for your interest, and let me know if I can help with anything! LyleHaze

I don't recall the details.. I ended up buying two.. the first was just too high res, it seemed like too much change per revolution. That can be controlled somewhat in software, but I went a bit too far.. I do remember buying it from Digi-Key, and I know it was an optical type with a pushbutton. On the MBMIxer I have only ONE control.. and this is it. Push to change channels, turn to set volume, Push and turn to set Balance.. Of course it's designed to be controlled remotely. I only wanted the bare-minimum local control on the mixer itself. Using mouse-guts is a cheap way to get an encoder, but how "repeatable" is the linkage? Especially for a jog wheel or scratch wheel, I would think that a direct linkage would give a more solid feel.. But hey, this is all about trying different things. An inexpensive mechanical encoder can give you a solid start until you get your core and software in place and tested.. then you can try homemade "Mouse Guts" type or decide to spend $20 for a hi-res optical unit... it's all about your own choices. Have Fun, LyleHaze

The Wiki has a good paragraph about the difference between pots and encoders. http://www.midibox.org/dokuwiki/doku.php?id=questions_and_answers Just look for "What's the difference between potentiometers, sliders, motor faders and encoders?" MIOS handles all the ugly details of reading the encoders for you. You might want to read the MIOS_ENC section at http://www.ucapps.de/mios_fun.html Or if you just want to react whenever the jog wheel is turned, you would write a function called "USER_ENC_NotifyChange" that will be called by MIOS every time an encoder moves. You'll find details on that in the function list too. Each encoder will need two DIN's to connect to MIOS.. SO a DINX4 which has 32 inputs could support up to 16 encoders. If your jog wheel will get a lot of usage, or if you want an especially high resolution, you might consider an optical instead of a mechanical type. I paid about $25 US for mine, and it will probably outlive me. Have Fun, LyleHaze

Hey nILS, What would that be in Imperial units? :shifty:

You are considering a "switching" power supply.. these regulate by rapidly switching the power on and off, and using an inductor and a cap to smooth the result. Switching supplies offer greater efficiency, less heat, lighter weight, and usually a load of switching noise. If you're building an all-digital project then I'd say "Go for it".. but since you are specifically trying to get a quieter power supply, I'd steer clear of anything with a switcher in it. Besides, an Amiga somewhere would be without power, and that would be sad indeed. :) The best choice would be to find a transformer that better suits your needs. Or better yet.. use that scope to look at the OUTPUT of your regulators.. if they are dropping out, it should be obvious. Good Luck, LyleHaze

I really wasn't sure which forum to put this into.. This project is in Java, so it's not MIOS.. and it's not strictly for MidiBoxes only, although it was inspired by MIOS studio and designed with this community in mind. If any admin thingks it would be better somewhere else, pleXMLMixerV0.8.zipase move it. This program will allow the end-user to design their own Java window with Midi controls.. At this point is supports Knobs, Sliders, pushbuttons and toggle buttons. The user can choose what goes in the window, where it goes, and what each control looks like. You can provide .gif images for buttons, knobs, and even the slider handle. You can also scale images to whatever size you want. You can assign Control change numbers, set minimum and maximum scale values, and even preset the controls to whatever levels you want. It supports MIDI in too.. and the controls should move to match whatever comes in (necessary for syncing multiple control sources) It supports multiple Midi inputs, and will merge all selected inputs to a single stream. It supports multiple Midi outputs, and will broadcast outgoing Midi to all selected ports. You get all this control just by editing your own XML file.. no other programming experience is necessary. This is my first Java program, and my first experience with XML as well, so I'm sure there are things I could have done better. If you find it useful, PLEASE upload your XML files for others to see. and upload your images too.. You'll see that I'm not very good with image editing. There's lots of really artistic people around here, I'm hoping that some of you will contribute better looking images to this project. Oh, of course it works best with MBMixer.. but that's another project. :)XMLMixerV0.8.zip Have Fun, LyleHaze

You didn't mention what kind of OS you are using.. In this case, that might be the source of your trouble. I know that the way Windows handles hubs has a few faults, and some programs work fine on the "root hub" but cannot handle being further down the link. Right now I'm using an 8X8 midi interface and the "class compliant" windows driver.. and because of how my workstation is set up, the MIDI interface is 2 hubs away from the computer. I had to try a few different hubs before I could get it to work (mostly) right. On my "other" computer, I can drive MIDI hard with any number of hubs, no problem. All I can suggest is to try a few different USB hubs and hope you find a combination that works for you. Good Luck, LyleHaze

Unfortunately, I don't think these will work.. It is a common limit of most chips that all signals must stay between the upper and lower voltages of the chip supply. In the case of the MAX5401 and the Microchip option mentioned, the voltage on the resistor leads are limited to: Maxim: ABSOLUTE MAXIMUM RATINGS VRange -0.3 to VDD + 0.3 Microchip range 0 to VDD Close enough to call them the same... But if you read the schematics, most of those pots are subjected to anything between V+ and V-.. and the power supply page shows V+ as +9, and V- as about -10 volts.. SO.. the application is well outside the maximum voltage ranges of the chips you have selected. I wish I was giving good news.. LyleHaze

As long as I used my old page link, midibox.org Forum - Index I had to log in every time I came here. But as soon as I switched to a link I picked up from the "improved" site, I get logged in automatically, as I had hoped. SO if you're having auto-login troubles, maybe try picking up a new link. I use this one now:New Link Good Luck, LyleHaze