lylehaze

I don't think so.. A quick look at what J5 really is.. it looks like 8 analog inputs. Those are connected to AIN modules that can multiplex them into as many as 64 inputs, each one being switched among 8 possible inputs, 8*8=64. SO.. you can take all of J5 and three pins from A6, and connect your AIN modules for a maximum of 64 analog inputs.. OR, connect eight analog inputs directly without any AIN modules or any need for J6. OR use those eight inputs from J5 as digital inputs, IF YOU HAVE NO ANALOG INPUTS AT ALL. As always, someone smarter will correct me if I've got it wrong. LyleHaze

For the fuses, you have the right idea. It's not something to lose sleep about. Each fuse needs to be rated above the maximum operating current, and somewhere below 300% to 500% of the operating current, as long as it is still fused below any safety issues.(not a problem with ma DC levels) Fuses are meant to protect from extreme overloads, as might be encountered during a dead short or complete failure of some system. If your system normally draws 70ma, then a 100 ma would be great. If all I could find was 0.25 amp or even 0.5 amp, I'd use those without worry as long as the power supply was capable of blowing them if something extreme happened. Capacitors? Enough is good, a bit more is better. Electrolytics will derate with age, Tantalums will explode if voltage spikes. going crazy over-filtering the supply will create large inrush-currents when you power up. Past that you're on your own. :-) Have Fun, LyleHaze

the 7805 will "shut down" if its output is shorted or overloaded. Unplug all modules from the core, then try again. If that works, connect each module and power up again, to test each module. (do NOT connect or disconnect modules while the power is on) If one of the modules has a short, you'll find out which one this way. But if EACH of the modules works fine, but you cannot get ALL of them to work at once, then you probably have too much load for your 7805. to reduce the heat on your regulator, you can: Add a heatsink. Reduce the DC input voltage to as low as 7.5 volts Use multiple regulators to power your project. But probably you'll find a short and once that's fixed you'll be all good. Have Fun, LyleHaze

Thorstens first link was to an archive of Jeff Glatts old MIDI site. It was a great MIDI reference website, but it has been gone for over a year now. I did some research and actually found Jeff. I wanted to find a new host for his site, but he had already done so. He has given me permission to share the new address. http://home.roadrunner.com/~jgglatt/ You'll find the same page that Thorsten showed you there, under "Technical Docs and programming","The MIDI Specification","Syncing Sequence Playback". You will also find a lot of other great information about MIDI. Big thanks to Jeff Glatt for keeping the site alive! LyleHaze

if you want to share a big heatsink with the negative regulators, there are ways.. There is a LOT of good power supply information in this thread.. and it seems to be a common discussion around here. I need lunch. LyleHaze

Everything I have heard so far is good.. I'll add a few more opinions, you are welcome to take or leave them. As with most opinions, some people may not agree. I'm not always right, but I try to stay open minded. Three transformers seems like a bit much, but your reasons why make good sense. I like making the 5 volts off a "private" transformer for a few reasons: it lets you reduce heat, by not stepping down so far from a higher voltage. Also, since the 5 volts is often "digital" and the others are "analog", keeping those separate reduces audio noise. Finally, you often need to support more current for 5 volts than all others combined, so if one was to be separated out, that would be the one. toroidal transformers? I believe (and I could be wrong) that they put off less of a stray magnetic field, but I don't think it's an issue that is worth going after. I do NOT believe they offer less electrical noise, and your power supply will be the factor that determines that. Switching supplies? great technology, but they can add high frequency switching noise to the power rails. If you're building an all digital and MIDI device, like maybe an MB64 that has no audio circuits, they are a great choice. but if there's audio being made, well.. I guess I'm old fashioned that way. Analog regulators make heat, but they don't add noise to the power supply, and another bad thing about switchers is that they are not usually repairable. (at least not easily) Deliberately over-rating all the parts in your power supply? I thought you were new at this. THAT sounds like someone with lots of experience. I think it's a very good idea. Power supply safety? Absolutely. Be VERY cautious anywhere near mains voltage. I like to build the power supply first, and once it's working and tested, I enclose it, or insulate it, or do whatever it takes to make it completely consumer-safe (good enough to let grandma use it). Once that is out of the way, then I can relax a bit as I build out the rest of the project. One last, tiny detail. I understand that your "mains" are done different than ours, but if you can get a "DPDT" or "DPST" switch for the power supply, then you can cut-off BOTH sides of the AC, just in case some fool electrician didn't connect it right (or the plug is in backwards).. that may not apply with your mains, but here in the US, I trust nobody. Oh, one other detail (you'll love this) 78xx regulators (positive) and 79xx regulators(negative) have different pinouts.. On the 78's it's IN, GND OUT, but on the negative regulators it is GND, IN OUT. Since the middle pin is connected to the tab, that also means that the heatsink of the 7912 will be at some negative voltage.. Check your datasheets, do NOT trust my memory. Sometimes the devil is in the details, but you knew that already. :-) (Now I'm waiting for a post telling me what an arsehole I am.... It's true!) Have Fun, LyleHaze

OK, after reading the datasheet.. the best approach might be to add a few PNP transistors so you can "switch" an analog input to +5 volts.. maybe..

Yup, I can give the ASM answer, but you'll have some lookup work to do.. and this might not work.. I'll try to point out the difficult spots as we go. Download the microchip datasheet for the chip you are using..PIC18F452 or whichever. Download the MIOS function reference.. Find the MIOS code to turn OFF analog multiplexing.. add that to your program. MIOS_AIN_UNMUXED?? It would be great to turn off MIOS analog stuff completely.. not sure how, but someone will chime in. In the datasheet, read up on configuring the analog inputs as analog or digital. THis may be a problem.. You can select how many are analog and how many are digital, but it's not a free form assignment. Usually, if you want just one analog input, it MUST be A0.. there is no option for making A0 digital and a2 analog, for instance. the exception is that one of those analog inputs may be re-assigned as a reference, but that doesn't help us. In the end, the ADCON0 and ADCON1 registers will control which pins are analog and which are digital. Then you can set bits in the TRISA register to split the digital pins into inputs (1) and outputs(0) Then you can set LATA bits to determine which outputs are HIGH (1) or Low(0). note: for the top three analog inputs, that will be TRISE and LATE, as they are in port E instead of A All of these can be set/reset/played with "live" while the program is running, if need be. I do NOT know what it will take to get MIOS to leave these alone. Obviously if it is scanning any analog inputs at all, then you may have to deal with that.. Note that using I/O pins to supply +5 and Gnd will not work if current requirements get near 20ma.. although you can get a FEW more ma than that, it will drop the voltage as you get near the limits. I think once all the details are worked out, you'll find it easier to wire up each side individually and not try swapping pin meanings from X to Y, if that is possible at all. That way you could avoid all this mucking around and get on to the fun stuff. Have Fun, (or.. Good Luck??) LyleHaze

Congrats on getting well started. Since I usually do asm instead of C, I may be giving bad advice, but I was faced with a similar challenge in converting from linear to log and back again. I eventually used Excel to calculate (and graph) the desired curve, then I abused it into writing the asm source code for me. It was a bit ugly up front, but I now have the easy means to alter the curve and re-generate the needed source code. If that sounds interesting to you, you will find the spreadsheet in this zip file: http://www.midibox.org/dokuwiki/lib/exe/fetch.php?media=pga:logcurve.zip It makes a nice bridge from the easy office spreadsheet to the source code. In any case, have fun! LyleHaze

Myself, I would not power ANY chip that I cared about without a decent regulator. Happens all the time.. :-) That explains a lot. Many brands of 78xx specifically state that applying a higher voltage at the output exceeds "maximum specifications", meaning that if it's toast, it's your fault. Congratulations, you have just voided your warranty!! :-) In the long run, it might be cheaper/safer/easier to build the "real" power supply first. Have Fun, LyleHaze

A few problems: Running 5 volts straight out of the wall wart without any local regulation may be a problem. Few of those supplies are regulated as well as would be needed. Since that 5 volts is your logic supply AND the "bottom" regulator for all other voltages, it should be as stable as possible. The problem is, before you can add a 7805 there, you'll need at least 7 or 7.5 volts to feed it. depending on the manufacturer, there is up to 2.5 volt dropout across the 7805. Another problem: The LED you have across the 5 volt supply needs a resistor in series, or it won't last long. Finally, for the voltage tests: If you are providing reasonable input power, most 78xx series regulators are fairly precise, being within 5% of their rated voltages. Try measuring each ones output voltage compared to it's own center pin, and you'll probably get just what you were looking for. The rest is up to your circuit. If the readings are still high, check your meter batteries. Have Fun, LyleHaze

All of the postings so far are for trigger to MIDI converters.. They can take some number of piezo triggers and convert them to MIDI OUT. You mentioned in your topic line that you only want mono.. the whole mono/stereo thing comes after the MIDI signals are converted to something you can hear. Nothing that has been posted so far makes any sound, at least not unless you use it to trigger sounds from your computer or synthesizer. On the topic of easy-to-use PIC programmers, the PICkit2 is small, affordable, supported directly in MPLab as well as from the command line, and works great right off a USB jack with no other power cords. The EDrum is cool kit.. I hope you find the info you're looking for. Good Luck, LyleHaze

CBX also supports multiple MIDI OUTs, though I think you can limit yourself to just one.

Thanks Twin-X. I feel more secure already. It will be a good day, LyleHaze

I'm a bit confused.. (Anyone who knows me will agree) The topic says you want to have a new keyboard built, but the thread says you are most interested in an AFM Synthesizer. Perhaps the best way to get what you want is to buy two separate devices. Buy a (used, older) AFM synth that has all the sounds you want, then control it from a new keyboard that is whatever size, shape, and key action that you are most comfortable with. Because the synth is not getting all the abuse, it will probably last forever, and you get the bonus of choosing the keyboard you want. If you want a "special" control surface to tweak the synth settings, get the tech manual for the synth and build what you want with a Midibox. I thought the original purpose of MIDI was to allow the separation of keyboards and synths, so that the performers onstage would not get lost behind a dozen keyboards. Just thinking. LyleHaze [edit] there is a "lightly used" TG-77 on E-Bay for $300. It is the rackmount version of the SY-99. That seems like the best way to get what you want.. and you get to choose your key action!

By default, the MIDI OUT port on the M-Audio keyboard will echo what the keyboard is doing. If you can find the right options, you can make the MIDI IN and MIDI OUT jacks work just like a USB-MIDI interface. You'll need to do this before you can use the MIDI bootloader for MIOS. 1.3.3 Using The Axiom with Your Software When installed, the Axiom appears as a simple MIDI device with two input ports and one output port. You should select the first listed Axiom input port as the MIDI input device in your software. Once this is set, your software should be able to receive notes and controller data from the Axiom. If you have connected external MIDI gear like a drum machine or another keyboard to your Axiom’s MIDI IN port, this gear can be interfaced to the computer by selecting the second listed Axiom input port. This way, your Axiom is acting as a MIDI to USB interface. It is also possible to stream data from your computer to external MIDI gear connected to the MIDI OUT port of your Axiom— effectively a USB to MIDI interface. To do this, you should select the Axiom output device in your software. Note that some other steps are necessary to make this work that will be fully explained later in this manual. later in the manual.. 4.1 MIDI Out from USB Function MIDI Out from USB can be used to switch the source of the MIDI data seen at the MIDI Out port of your Axiom. On initial power up, MIDI Out from USB mode is off. This means that as you play your Axiom, MIDI data will be sent to the MIDI Out port. If you turn MIDI Out From USB mode on, playing your Axiom will no longer send data to the MIDI Out port. The data is instead streamed from the computer. So, as long as you have selected your Axiom as the active output port in your computer’s sequencer, this is the data that will be sent the MIDI Out port. For example, if you want to control a sound module from your Axiom, you should ensure MIDI Out from USB remains off. If you want the sound module to play data streamed from your computer however, then you should turn MIDI Out from USB on and ensure that the output port for your Axiom is selected as the computer’s MIDI output device (this is done in your computer software). Hope that helps. It's all from your User Guide. To summarize: Connect the core to the MIDI IN and MIDI OUT of your axiom keyboard. Perform the following instructions to turn the MIDI Plug symbol ON: < Press Data 2 and Data 3 together to change the MIDI Out setting to MIDI Out from USB. < You will see a MIDI plug symbol appear on the LCD display. < To turn MIDI Out from USB mode back off, press the same button combination again. When you do this, the MIDI plug symbol disappears. Connect MIOS Studio to the second input and the first output from the axiom keyboard. That should take care of the MIDI connections.. that well-hidden switch for MIDI OUT has fooled a lot of people. Have Fun, LyleHaze

The problem is more than just SysEx.. I would not do it. You, I suspect, will do what you want to. Have Fun, LyleHaze

The Microchip Technology Inc. 24AA512/24LC512/ 24FC512 (24XX512*) is a 64K x 8 (512 Kbit) Serial Electrically Erasable PROM, So there it is.. 512 k BITS.. we usually use Byte-sized chunks. :-) LyleHaze

Madox: Well said, but I take one exception to your comments: As best I can tell, the problems with making a USB-MIDI interface that is PIC based are related to internal problems in the PIC devices. Based on what I have read, it is NOT POSSIBLE to make it right, unless you are somehow more talented than all who have tried so far. The PICs are broken, and until Microchip bothers to fix this, they will remain broken. Enjoy the day, LyleHaze

Because it works with "Class compatible" drivers, the GM5 should be replaceable with any class compatible interface if it should "go wrong". Only a device with a device-specific driver could leave you hanging in a bad spot. The bonus points for the GM5 include: being expandable up to 5 in and 5 out, being "embeddable" into a MIDI device so that only a USB cable is needed for connection, and the rather cool option of being able to add an eeprom and make "custom" text labels for each port. Even though this community is based on "Do It Yourself", we have seen a great deal of problems as a result of cheap USB-MIDI converters that almost work right. Because we NEED a solid connection from our computers to our toys, we have collectively learned that a dependable USB-MIDI cable is not a project so much as it is a tool. a tool that HAS to work right if we want to build toys with it. Have Fun, LyleHaze

Unlike most of the projects here, the GM5 chip is a commercial product. Ploytec gets to make all the choices regarding how to distribute their property. I think the bulk orders they have filled for our community represent excellent value, as well as an unusual willingness to work with hobbyists. Because the GM5 is "closed", I really don't care what silicon it's running on. But that's just my opinion. :-) LyleHaze

The PIC based solution is not reliable. I would advise against it. But it's your decision. Read more here: http://www.ucapps.de/mbhp_usb_pic.html Have Fun, LyleHaze

There are questions... Did you buy your PIC from Mike or Smash? There are a few steps.. Burn the bootloader into the PIC (requires a PIC burner), not needed if you bought it from Smash. Set up your computer to run MIOS studio. Load MIOS into the PIC using MIOS Studio.(not needed if you got your PIC from Smash.. I THINK) Load the application into MIOS using MIOS studio. Try this link for details: http://www.ucapps.de/mios_bootstrap_newbies.html If you have troubles, test your MIDI interface by doing a loopback test. All the details should be on the page I pointed out. Have Fun, LyleHaze

Do you really think that the delay differences between a Darlington pair and a BJT will be significant when compared to the physical delays involved? I really don't know, but I usually assume that the longest delays are the physical ones, especially when building momentum from zero to x is involved. I'd build one to find out, but I have WAY too many open projects already. :-) LyleHaze

It seems you have three choices: Either buy a matching cylindrical jack and wire that to J1, Change the cylindrical connector on your power supply to a 2 pin connector to match pins at J1. Or cut the plug off and wire the adapter directly to J1. The connector choices are the best choices, so you can connect and disconnect your power supply. Have Fun, LyleHaze