SounDuke

Hi, I purchased a 7805CV, looks like this is stopping me from powering MB64 with only a display and a few buttons and pots (ca. 200 mA) with 4 AAs. It is obvious since datasheet says that 7,5 V are required to mantain line regulation. Is there a 7805 which requires at least 6 V? I can't add 2 more AAs due to lacking space on case, I suppose a regulator with low power consumption exist since people who powers their MB with 4 AAs are a lot on this forum, can you give me an hint? Thanks!

In my new design, I was wondering if I'll encounter problem with the following setup: I built a pedalboard with 60 keys, installed in it 2 DINx4 and I'd like to connect J1 of the first DINx4 on a 9 poles subD port. 2 m away I have another panel stuffed with core, LCD with the 4 navigation buttons near and 8 pots and another subD 9pole port. I would like to connect the 4 buttons to the female subD on the panel with the pots and the remaining 5 poles to J9 of core, so that core J9 and DIN J1 are connected this way, while the 4 buttons are connected to the serial pins of Dinx4. Do you think I'll have jitter problems? Since those are not analog signal I assume that I'll avoid self-playing keys right? The cables which are near and 2 m long are the connections between core J9 and din J1 + serial pin to buttons. Thanks!

Thank you Thorsten ;) I found a way out to customize my MB64 design, your help is truly valuable. As soon as I complete that damned case I'll post photos on forums! :D

I had tried this yet, in fact improvements were very slight. TK, do you think that mantaining the sub D port but using shielded cable I can fix the problem? I should use shielded cables for every pin of faders (Vss Vdd and wiper right?) and has anyone got an hint on good shielded cables without exagerated dimensions? thanks

Well, it happens that sometimes the two faders send random values of the controllers they are assigned to. And every time I move them or move the knobs the MB sends out those damned random values from the faders... I'm in a deadlock, it seems like the supply pin of the faders are floating, is this because of the length of the cables? I can't use shielded cables since they're too thick for my purpose.. Any idea?

I forgot: I donwloaded Thorsten's jitter_monitor app and I see jitter values from 01 to 06, worst case 08. I don't pretend to eliminate jittering, but at least eliminate the random data from the 2 faders.

Hi everyone, I read a lot of topics regarding jitter and signal interference between pots, but none seem to solve my problem. I have the following hardware on my MB64: 1x core 2x din I didn't stuff the hc165 on the DIN because I'm experiencing problem with pots and I would like to solve that issue first. They are connected on j5 of the core so I have 8 pots w/o multiplexers. 6 are knobs, 2 are sliders. The pots are connected near the core and they work perfectly, but I experience a lot of interference when I connect the 2 sliders. It is quite normal since the faders are connected via ribbon cable to j5 pins through a subD 25 pole port to another panel (about 2 metres of cable) and the Vss Vdd and wiper cable (4 in total) are very near. I have random data ONLY from the 2 faders, when I move the knobs or when I touch nothing. Is there a solution to this? note that the faders cables are very near to the display cables too, I tried to stuff a cap (different values from 330 pF to 1 mF) between Vss and Vdd, but I noticed only a small reduction of signal noise. Is the length of the cable the problem? Thanks in advance!

No problem - works perfectly and no jitter :D

Hello everyone, I built on a vectorboard a nice control panel with display and 4 buttons+2 sliders to control midibox64. I've got this about 1m away from core and din module, since the control panel is plug and play with a 25 pole subD connector I used 16 poles for the LCD and now I have only 9 wires available to interface 4 buttons and 2 faders. Can I save wires for ground connecting the Vss poles of buttons and faders directly to the chassis of the modular control panel? So that 1st Fader and 2nd fader use 2 wires for Vdd and wiper 4 buttons: each one a wire for Vdd total: 8 wires used Thanks in advance and keep up the good work!

I don't think this would be that effective: Midibox sid is an high quality synthesizer in its class, I own a sidstation and it is useless to compare them. If this is not enough, for what I know Elektron has discontinued building Sidstation, so a sid based synthesizer with full midi implementation is becoming a dream for most people. After finishing my midibox sid I received a lot of requests "please please build me one" from people resembling children asking for a ice cream. Here in Italy people would spend 200 € for a MBSID instead of learning a few basic notions of electronics (Even I was able to build a full fledged MBSID! Everyone can do it!). But not everyone is going to refuse as I did and there's no law or supervision which stops people from doing it. That's the price to pay for being a unique community like Midibox. These things make me feel sick

Thanks Moebius! As always good tips from you :D I don't know if common normally open pushbuttons are reliable for good velocity sensing :D

Hello everyone ;) I finished my MBSID and MB64, I'm planning to add a keyboard to them. Since I read the reply of TK to a post of a midiboxer who wanted to have buttons interfaced to DIN module capable of sending midi note on, I'm quite sure that because I don't possess experience with PIC assembler neither time to learn, this is going to be a hard work :D So I thought of routing note on message to midi in of MBSID and MB64 from this midi encoder http://www.geocities.com/midiboutique/ (mkc-MG). I could build a matrix of buttons for the MBSID and connect it to a mkc-MG, then route the midi out of the encoder to midi in of midibox. The same for MB64, with another matrix and another mkc-MG but I'm using push buttons from arcade games for this one, to turn it into an impressive keyboard midi controller :D It's an expensive way out (100 € for both encoders), but I need a keyboard for my midibox, do you know if there's a better and cheaper way to achieve my objective? I don't want to use casio or similar things because I need a more personalized keyboard (very small for MBSID and very big for MB64) Thanks!

http://cgi.ebay.it/ws/eBayISAPI.dll?ViewItem&category=4660&item=7508177952&rd=1&ssPageName=WD2V I noticed it has got touch screen too. Is it possible with mios to eliminate the buttons needed for menu navigation and use the touch screen as navigator? Thanks

Solved this one too. Better not tell you the reason of that short or Thorsten himself would solder my butt together :D

When I connect J5 Vss to the chassis, I experience a short circuit. I'm pretty sure this is because of a component, maybe you can help me tracing which one is it? The weird thing for me is that when I do not clamp Vss to the chassis everything goes ok, woltages too and the pic runs without problems except that the 8 pots connected to J5 send occasionally random midi data when I turn them.

Hi everyone! Since I can't have velocity with serial DIN inputs, I was thinking to use this module http://www.geocities.com/midiboutique/manuals/mkc-mg-usman.pdf to create a 5x8 matrix. Connecting this module to the midi in of core should do the trick. The only thing I am worried about is the priority of events: can I control a parameter with pots connected to AIN and at the same time press a key connected to the module without loss of data (Mios gives priority first to serial inputs from AIN or from midi in?) or is it able to manage in realtime midi events coming from both modules? Thanks

Well, the transformer is stabilized and switched to 9V, but the effective current is 10V so I think it would be bad to leave out the rectifier and the voltage regulator.. Maybe the cause is the lcd, my transformer delivers 500mA and the 7805 in the core gets hot. I haven't a PSU so I was thinking to put two separate alimentations since my midibox has a new mios implemented function: MIOS_TIMER_COOK CHICKENS :D. However my intention was to build step C, which values for the transformers do you suggest for the separate alimentations (I'm going to use the C64 power connector and switch, but no PSU) with all sid modules stuffed with 8580?

I'm a little worried about it because people from the community who use an 8580 say the chip is "ice cold" :D mine is angry

My fault, I did not notice the hardware mod needed for mios v1.7 ;) However, Is it normal that the sid gets warm after few minutes from power on? I use a stabilized 9Vdc transformer for both core and Sid

I built the minimal hardware requirements for midibox sid and uploaded the midibox sid 8580 withouth CS on the pic. Just to test, I connected an LCD to the core and tried to send some notes to the sid with midiOX. After power on, I hear a high pitch note for a while, then the hum of the 9v voltage. If I send a midi event, I hear continously the high pitched note, sounds like the Sid resets itself when serial data is received. What do you think? All connections seem to be okay

Hi everyone, I decided to use the 8 analog pins of core j5. Which is the best way to connect each ground pin of the pots to the Vss pin of j5 and each 5v pin of the pots to Vdd of j5? Since J5 has Vss and Vdd there's no need to connect ground pin of the pots to the metal chassis right?

Hello, first of all I'd like to thank the whole community, this forum is truly a valuable source of info, with a quick view I was shooting troubles like in bird hunting! Unfortunately there's something I couldn't understand. I saw that it is possible to use J5 as a digital input if multiplexers in the source code are disabled. Anyway, I didn't understand how to connect analog pots to j5. Is it possible? To have 8 pots which regulates midi parameters from 0 to 127 I absolutely need an AIN module with the multiplexers or I can use J5? In main.asm I read that I can have up to 8 pots with multiplexers disabled. Thanks!

Thanks for the advice, but there's something I can't catch: I have to supply the transistor array with another power supply of 5V right? So I'll have a power supply for the VE module (3V) and a power supply (5V) for the DS2003 right?

Well, since VE is programmable in C language, I should only train it with 11 different words and then write an app which activate the 3V output in the output assigned to the uttered word. I think the most difficult part for me is the integration to DINx4. What do you mean by "driving the base of an NPN transistor? I have to supply that transistor with another 5V supply?

The dinx4 I built is low active, the input pins when no buttons are connected stay at 5V. To send a signal to the pic I should send 5V to a digital input from the VE module in order to have 0V on that input and thereby 0V=on right? I noticed that VE module is supplied by 3V. The problem is that I can supply only 3V from the VE module. Do you think it will work or i need absolutely 0V?