Duggle

hi Vercengetorex , I think the main substantive criticism of what has gone on is, that it is parasitic on the midibox community if there is a flood of support requests from people with no interest in building midibox stuff. This is clearly not your situation. If you support your clients so that they get what they pay for then all is well. If you interact with the midibox community in this endevour, then I dont see how your different from a musician midiboxer who hopes to make money from his music or runs a studio or whatever. I think it makes sense that people who build midiboxes whatever thier motivation, potentially contribute to midibox community. On the other hand people who's only envolvement is paying for and using midi controll surfaces really have little/nothing to do with the welfare of the midibox community.

Hi, Ive made a surge of progress over the last 2 weeks and now have basic functionality of auto detecting and decoding any combination of mice and keyboards into basic midievents. The midimerge port provides passthrough of an external midi source (no sysex passthrough yet). I am currently refining the I/O engine to handle worst case throughput without errors. (Average case throughput is fine). I will also look at supporting a wider range of devices. Does anyone have specs on the toughpads? (Do they look exactly like a mouse to the ps/2 interface?) I'm interested in info on any other kind of PS/2 device midiboxers may want to input with a view to including as many devices supported as possible. Unfortunately I have a very busy 6-8 weeks ahead so progress will slow a little, however the release of this code and various h/w versions to the midibox community later this year is assured! (hey, Ive been on this ps/2 "hobby horse" for nearly a year and I ain't stopping now! :D) cheers

hi Thorsten, I can test it on my standard mb64. cheers

hi smash, points taken! I think its worth taking the time, at least for now, to state the reasons why things are done the way they are done and what is at stake and why. cheers

Hi, please correct me if I'm wrong, but the only thing SMG did that was wrong was publish the picture of the Midibox that was clearly not the kit they were selling. Also not crediting the work of the originator! These are serious issues but the principle of selling kits of "public domain" IP is something I support, in that it provides DIYers a valuable service, and is an honest enterprise. So long as it is tranparent and it offers what it gives and reveals it's sources then there should be no complaint. cheers

hi, just a few points to consider: the brightness of LED's is directly proportional to the duty cycle. The update of DOUT modules is in the 10's of uS. Flicker becomes visible 50->100Hz. -> period of dutycyle < 10mS This suggests that what you mention is do-able with 6 DIN modules. The number of levels of brightness will be determined by the acceptable period.

hi, trial and error is a good idea, so only buy a couple of parts until you know the results are satisafactory. Without knowing what light source your using (I will asume natural light), the one with the lowest "light" resistance should be best (N59AY from your list). If you use R attached to 5V end and LDR to ground. Try 22k,47k,100k,220k some will give a lower minimum and some will give a higher maximum. Swap the LDR and R to reverse the response. A pot is not a good idea in that if it is in the "short" position you will get maximum current int the LDR and may destroy it. If you use a 10k resistor in series with 1M trim pot this should be ok though. cheers

hi the simplest effective way to do this is to connect the LDR in series with a fixed resistor between 0 and 5V and connect the junction to AIN. (ie voltage divider). The value of the fixed resistor will determine the operating range. It may not be possible to produce output values close to 0 and 127 because the LDR will have a limited "light" minimum resistance and limited "dark" maximum resistance. Using more complicated circuitry it is possible to overcome this limitation but whether it is worth the design effort would depend on the application. cheers

well done, indeed, the point Ive been trying to make in this thread is that the total current available from the 7805 is not the limiting factor (>1A!) but the heat produced when regulating down by a significant voltage. Remember the diodes in the recitifier will contribute a constant drop of about 1 to 1.2V total. This means that the regulator is seeing about 6.3 to 6.5V across it's input, which is about perfect as far as minimising the heat goes! cheers

If you keep the 5V outputs from the two regulators separate, you can supply a different set of Vcc's on each. This will not reduce the total heat just spread it out between 2 devices which in most case wont be a real help. It also means you have to separate the Vcc (+5V) wires into 2 groups to split the load...

hi, just to add my earlier post: The heat dissipated in the voltage regulator (measured in Watts) is determined by Voltage multiplied by current. The voltage is the voltage drop from input to output of the regulator. The current is the load current being supplied. eg midibox current= 200mA =0.2Amp input voltage=12V power(heat)=0.2*(12V-5V)=1.4W now with lower input voltage midibox current= 200mA =0.2Amp input voltage=6.5V power(heat)=0.2*(6.5V-5V)=0.3W less than 1/4 heat produced!

one way of making of making the 7805 run *much* cooler is to feed it with a lower input supply voltage. The lower limit input supply of these 78xx voltage regulators is 1.2V above the output voltage. This means using 6.2V on input. Make sure the input voltage never falls below 6.2V during the AC cycle otherwise your 5V regulated output will dip causing possibly quite subtle problems. Feeding your midibox core with a regulated 6.5V plug pack would be perfect. cheers

my undstanding is that the hardware samples at 10bits and MIOS has this data available but most applications reduce the resolution (and jitter) to fit the 7bit midi CC format. So, yes this is possible but you will need to some code to use it. cheers

hi, the MIDIbox LC would be a good place to start. see uCApps.de cheers

hi, a simple single pole changeover switch could be used to select wether midi-in comes from the max232 or the opto. This avoids the short circuit of the opto and the max232 trying to drive the core's midiRx line in opposite directions. Midi-out connected to both max232 and midiout does not imply a short circuit, however the baud rate will be wrong for one of the outputs. If you use one double pole changeover (switching both midi-in as above and midi-out) you will avoid sending the wrong baud rate if both types of devices are connected to your midibox. Of course when you flick the switch to change midi/rs232 you must change the baudrate in the midibox. cheers

hi, a simple single pole changeover switch could be used to select wether midi-in comes from the max232 or the opto. This avoids the short circuit of the opto and the max232 trying to drive the core's midiRx line in opposite directions. Midi-out connected to both max232 and midiout does not imply a short circuit, however the baud rate will be wrong for one of the outputs. If you use one double pole changeover (switching both midi-in as above and midi-out) you will avoid sending the wrong baud rate if both types of devices are connected to your midibox. Of course when you flick the switch to change midi/rs232 you must change the baudrate in the midibox. cheers

hi, thats sounds great, do you dunk in water (the pcb and paper) after ironing, while still hot. (this works great with plain paper). Or do you just peel the paper of immediatly, or when cool? thanks

hi, thats sounds great, do you dunk in water (the pcb and paper) after ironing, while still hot. (this works great with plain paper). Or do you just peel the paper of immediatly, or when cool? thanks

hi, yes I lurk from time to time ;) I'm really busy with study these days but I would like to "finish" this one during my midyear break. I have implemented ps/2 I/O functionality (for keyboard and mouse) as well as midi-merge. I have a bit of debugging to do but the idea is to have (1xCore) support up to 4x ps/2 ports (for say 2 kbds, 2 mice ) and a midi in and midi out With the midi merge function system integration is really easy as you just cascade control surfaces as many as you want. You set up your host application to do what you want with the midi events. So the IIC I/O becomes less important given that midimerge will allow integration fairly well for most users. I guess its still a couple of months before I can look at it again. cheers

yes, this is very easy, just a hint, if you are going to power the op amp with the 5V supply common to the rest of the circuit, you should use a rail to rail op amp (capable of outputing voltages from close to 0V up to close to 5V).

hi, if youre planning to merge the output of rack units for the purpose of saving sysex dumps etc. and you are able to control the dump requests to make sure they are not simultanious then why not OR the inputs by connecting the open collectors from the optos? (dead simple solution!)Of course active sensing or timecode from any of the inputs would shag this approach :-/ A more sophisticated approach whould be a multiplexer with a arbiter circuit to prevent interruptions to the midi stream (still much simpler than 8 UARTs and buffers and plenty of firmware to write!). The suitable solution really depends on what you need the merger for.

yes it will work, make sure you identify the switch common wire (gnd), wire it to one side of your expansionbox switches, take the other wire for each switch from the existing switches you wish to "mirror".

guys, why not use a low cost DB9 plug/socket which would carry the switch common plus 8 switch wires. Simply connect the switch wires to 8 (or 5) of the existing midibox switches and loop them to the DB9 socket. If you want 8 new midibox buttons why not mount a single shift register IC (same as used in DIN) on a tiny piece of matrix board and mount that in in your pedal board and wire it with five conductors back to the midibox (as suggested earlier).

I don't know what the fuss is about, after all, NewYork is the centre of the planet, and besides most midiboxes are sperical and do have sliders and flexible skin that can be withdrawn to solder connections underneath. ???

I agree with mobius, in fact if you used if you used signal quality sheilded relays mounted "in" the PCB and motor pots there should be no sound quality degradation from the original at all. cheers