TK.

Initially I planned to nominate only one well-made MIDIbox design per week, but this time it's really difficult.. in the last days I got photos from three outstanding projects which are the dream of everything from us :) So here they are - just choose your private favourite: MIDIbox64 with integrated TB303 synthesizer by Tom303: MIDIbox64 as "typographical synthesizer" by Rob: Multi-MIDIbox environment with a lot of motorfaders/encoders/buttons by Axel: Best Regards, Thorsten.

Hi Andre, normaly there isn't a buzzing sound - just download the schematic from the MBHP SID page and follow the tracks. Check especially the polarity of the rectifier and the electrolytic capacitors! I've no experiences with the MultiPic burner - are you able to verify the flash content? On this way you can ensure that the programming was successfull. Therafter you can do the following test to check if the program is running: start MIDI-Ox and send a program change to the MIDIbox SID: it should response with a lot of controller events (the sound parameters) Best Regards, Thorsten.

Hi Christoffer, the second AINX4 has to be connected to exactly the same pins like the first AINX4, expect for the analog outputs of the AINX4 module - they have to be connected to J5:A4-J5:A7 a connection diagram can be found here: http://www.ucapps.de/mbhp/mbhp_ainx4_64pots.pdf Best Regards, Thorsten.

first check the diodes, if they aren't connected in the right direction, the fader will not move. I think that this pictures explains more than 1000 words ;-) And check the voltage behind the LM317 during the motor is running. It should be stable and shoudln't go down under load. Best Regards, Thorsten.

I cannot recomment it, since the current drain of a LED (ca. 20 mA) is too high for the JDM circuit. It would only work with an external power supply for the LED + a transistor as electronic switch, but do you really want to spent so much effort just for a LED? Best Regards, Thorsten.

Hi Ian, since the current MIDIbox MF design is a realtime system with a defined update cycle, the faders won't be moved slower or faster... but possibly some features will be provided in the next years which are really usefull for the daily work and cannot be implemented with a PIC16F anymore (especially RAM consuming features) Best Regards, Thorsten.

Does the rest of the circuit work correctly? Does your computer receive any MIDI data? Did you adjust the contrast pot so that you see anything on the display after poweron? Best Regards, thorsten.

yes - and with an additional shift register for the DIN, you can control all LEDs with 32 buttons. I will add a more detailed description about the button/LED assignments in the next days. Best Regards, Thorsten.

Hallo Malte, ueber Pin 2 und 3 werden normalerweise keine Pulse gesendet - das sind analoge Eingaenge. Wenn Du schon ein Oszi zur Verfuegung hast (ich hoffe, dass hier nicht der Eindruck entsteht, man koenne die MIDIbox nur mit teuren Geraeten debuggen ;-)) dann schaue Dir mal den XTAL1 an - an diesem Pin muss ein 20 MHz Sinus zu sehen sein. Interessant ist auch die Enable-Leitung zum LCD: die muss waehrend des Einschaltens wackeln. Mit einem PIC-Programmer koenntest Du auch den Flash-Inhalt ueberpruefen. Dazu musst Du lediglich die Firmware, die sich im PIC befindet/n (sollte) in IC-Prog (o.ae.) einladen und den Verify-Button anklicken. Gruss, Thorsten.

Es geht noch einfacher: Du kannst den Tx-Pin des PICs auch direkt an den Rx-Eingang des GamePorts anschliessen --- ohne Optokoppler dazwischen. Zusaetzlich muessen dann auch noch die Masseleitungen miteinander verbunden werden. Im MIDIbox Plus Hardware HowTo findest Du dazu einen Schaltplan (demnaechst wird es auch eine eigene Seite geben, auf der alle Moeglichkeiten aufgelistet sind) Gruss, Thorsten.

Zusammenfassung: o to-COM spielt mit Deiner Windows XP installation nicht zusammen o MIDI-Out Deines PCs/MIDI-In der MIDIbox funktionieren o MIDI-Out der MIDIbox/MIDI-In Deines PCs funktionieren nicht Einfachster Test: schalte den MIDI-Merger ein, die to-COM Option aus, schicke mit MIDI-Ox eine Note zur MIDIbox: Die Note sollte genauso zurueckkommen, im MIDI-Ox-Fenster sollte alles, was zur MIDIbox gesendet wird, doppelt angezeigt werden (einmal als internes, einmal als externes Event). Falls MIDI-Ox stattdessen ein Pitch Bender Event anzeigt, kann der Fehler eigentlich nur noch am MIDI-In Deines PCs liegen. Der CNY17 ist ein wenig problematisch, mit einem 6N138 oder PC900 wuerde der MIDI-Eingang sicherlich zuverlaessiger funktionieren. Probiere mal verschiedene Pull-Up und Vorwiderstaende aus, so wie unter http://www.ucapps.de/howtodebug.html beschrieben aus (was fuer die MIDIbox Plus gilt, ist natuerlich fuer jede andere Schaltung mit dem CNY17 gueltig) Gruss, Thorsten.

Hi Frank, I never have tested the MIDIbox MF with less than 8 faders, maybe the timer interrupt consumes more cycles in that case and therefore causes a MIDI overrun. I will check this when I'm home again and evtl. release a fixed version. To 1): this error occurs when the MIDIbox receives a MIDI byte before the last byte has been processed. In my interrupt routines I have to ensure that this case never happens - I will check it. To 2): The feedback elimination routines are working on the following way: when a fader is moved manually, all incoming events which are assigned to that fader will be ignored for 250 mS - this ensures that the motor doesn't start to run during the manual move. For the other direction: when a fader has been moved by the motor, no MIDI event will be sent for 250 mS - on this way a feedback (MIDI program -> MIDIbox MF -> MIDI program -> MIDIbox MF -> ...) will be prevented. Best Regards, Thorsten.

Hi Frank, yes :D you must know that the LM317 has a different pinout compared to the LM78xx. Take a look into the PCB layout, where you can see, which component has to be connected to which pin. Random values: you should take care for the connections between the analog inputs of the PIC and the faders. The cables should be very short (less than 30 cm) and shielded to ground. Otherwise the analog signals could be affected by the motor driver signals. Best Regards, Thorsten.

Yes, the core will work (it's 1:1 compatible) --- but the 20 MHz crystal has to be replaced by a 10 MHz type, since the PIC18F452 contains an internal PLL which quadruples the clock rate. Best Regards, Thorsten.

Hallo Stefan, dieses Fehlerbild ist mir voellig neu. Wenn die Baudrate falsch waere, muesste die MIDIbox z.B zufaellige Events senden. Pitch Bender Events sollten nur dann versendet werden, wenn sie auch einem Poti/Button zugewiesen wurden.... Der Fehler muss irgendwo ganz anders liegen... Kannst Du mir mal mehr Input geben? Welche Events siehst Du auf dem Display (einfach mal durch die verschiedenen Display Modes blaettern). Welche MIDI-Schnittstelle haengt bei Dir am PC, wie verhaelt es sich mit der to-COM Option und dem Roland Driver? Gruss, Thorsten.

Tja, so ist das mit Windows... :-/ Verzeihe die dumme Frage, aber hast Du im Merger Menue auch die richtige Interface-Option eingestellt? Wenn Du die normale MIDI-Schnittstelle verwendest, muss to-COM deaktiviert sein, ansonsten passt die Baudrate nicht (passt zum Fehlerbild). Gruss, Thorsten.

Jep, das passt schon. Du muesstest dann halt noch im Source code in led.inc die LED-Register invertieren ('movf LED_x, F' durch 'comf LED_x, F' ersetzen). Am besten gleich mit v0.34, fuer aeltere Versionen uebernehme ich keine Gewaehr (ich weiss ja, wie ungerne Du updatest ;-) Hast Du mittlerweile eigentlich schonmal die neue MIDIbox MF beta ausprobiert? Gruss, Thorsten.

Ok, this explains everything. Before trying various resistors, you should check if the optocoupler circuit is really correctly connected to the Rx pin. You could also try the second optocoupler which is currently connected with RA4. Best Regards, Thorsten.

Great to hear that it finally works :) Best Regards, Thorsten.

It's available at Farnell, see the http://www.ucapps.de/mbhp_bankstick.html page for the order number. Best Regards, Thorsten.

If you have to switch between the modes very often, I could compile a special version which allows to select the mode with the spare pin (J14 of the core module). In this case, you have to connect a 10k pull-up resistor between J14 and +5V and can select the to-COM option by using a jumper to ground. I have to test this version, because I don't know if it already works correctly. You will get it next week (I'm not at home and currently have no access to my source files). Best Regards, Thorsten.

Yes, I forgot to add this to the list (fixed) It would be great if somebody could evaluate the quality of this programer, just to save my effort. I already own the PICstart kit by Microchip and therefore have no problems to program the newer PICs... Best Regards, Thorsten.

During the last weeks I got a lot of hints regarding the new PIC18F family of Microchip. In the meantime the more advanced microcontrollers are also available for hobbyists, and the public domain community began to write tools for programming the chip. I already played with a PIC18F452 two months ago to evaluate the possibilities. The PIC18F452 is 1:1 hardware compatible to the PIC16F877 (the heart of the MBHP core module), and is currently available for about 15 EUR at Conrad.com (Europe), US$9 at DigiKey (USA), AUS$25 at "unknown" in Australia (the user didn't tell me where to buy it). In fact the PIC18F452 is worldwide available for the same price like the PIC16F877! And I expect that also Reichelt will offer it next year for less money (about 10 EUR). Compared to the PC world the difference between the 16F and the 18F is like between a 286 and a 486 - the 18F452 has 2 times more flash memory (and a reduced code size), 4 times more RAM, runs with 40 MHz, has some new instructions for table read/writes (appr. 16 times faster than 16F), mutliplication (about 50 times faster), multiple pointer handling (3 instead of 1), Stack handling, ... but the best: it has a linear program memory which helps to reduce the development cycles a lot! It was very difficult for me to balance, when I should introduce my plans, which features I should already implement with the 16F, when I should start to migrate the firmwares, when I will support the new chip. But now everything is clear, so here are my notions: Most of the features which are already on my ToDo lists will be implemented for the PIC16F, because as long as it doesn't get too complex, the PIC16F877 is still sufficient: advanced MIDIbox64 sequencer with dedicated firmware finished MIDIbox MF MIDIbox-Link more features for MIDIbox SID I think that these projects will be finished end of this year. Thereafter I will support the PIC16F firmwares only for bugfixes anymore, and will completely switch to PIC18F with my new project. It is the MIDIbox SID with control surface MIDIbox NG The MIDIbox NG will be a combination of MIDIbox64, MIDIbox16E, MIDIO128 - in fact I will merge all existing routines to a single firmware which will act as a MIDI Operating System (MIDI OS or short: MIOS ;-) ). The MIOS will support 128 analog inputs, 128 digital inputs, 128 digital outputs: up to 128 pots or faders or 8 motorfaders (since they cannot be multiplexed) up to 128 buttons or 64 rotary encoders up to 128 LEDs or 64 LED rings the MIOS will also come with some new concepts, which were already discussed: Display plugins (make your own MIDIbox skin for LED display, graphical or text LCDs) Meta Event plugins MIDI processing plugins IO processing plugins Plugins will be exchangable via MIDI, so that you don't need to connect a programmer to the core module, just to play with the code. The MIOS will be programmed in assembler, but plugins may also be programmable in the C language. My hope is, that the GNU community starts with a gcc for the PIC18F family, like they did it for Atmel AVR. This all may sound "expensive", but it isn't. In fact it will still be possible to build a very reduced MIDIbox with (for example) 16 pots and 8 buttons for less than 50 EUR! The advantages: only one scalable firmware for all projects will reduce my support effort a lot, and with the plugin technology everybody will be able to program and provide own features for the community. :-) Btw.: beside of the ongoing 16F development, there is another thing which prevents me from switching to the 18F family now: although IC-Prog is able to program the PIC18F452, it will not be possible to use it in conjunction with the JDM, since the programming current is too high for this design. An external power supply is necessary. So, I hope that somebody introduces a cheap and stable PIC18F programmer on the web until next year. Update: With v1.05A of IC-Prog, the JDM can be used to program the PIC18F452! - so, this issue has been solved! Best Regards, Thorsten.

Hallo Andre, eine Liste findest Du unter http://www.ucapps.de/mbhp/mbhp_sid_orderlist.txt Die unterschiede zur Original-Schaltung sind dort ebenfalls aufgelistet. Welche Bauteile fehlen Dir denn? Gruss, Thorsten.

Hier treffen zwei fehlertraechtige Dinge aufeinander: a) Onboard Soundkarten werden von den Boardherstellern meist recht stiefmuetterlich behandelt und sorgen immer wieder fuer Probleme. Aber vielleicht ist ja nur der MIDI-Interrupt deaktiviert, das wuerde zumindest erklaeren, warum der MIDI-In Deines PCs nicht reagiert. Ueberpruefe mal im BIOS-Startup-Menu unter "Onboard Peripherals", ob dort der entspr. Interrupt freigegeben ist. Defaultmaessig steht der Schalter sicherlich auf disabled. b) Windows XP. Probiere mal den Roland Driver aus, der funktioniert angeblich besser mit den neueren Wintendo Versionen. Gruss, Thorsten.