Megadrum by Japi - Documentation / Pictures -

[japi]

The only alternative to 74hc4851 is to use any variant of 4051 with bat85 diodes (or equivalents), i.e. using my original schematic.

I'll leave that as a last resort, isn't funny to make so many holes and soldering
Thanks !

viewtopic.php?f=3&t=187&start=0#p2455

Yes, i have seen that, in fact, i've asked about this before But didn't know if that applied to dmitri's schemas as well.. thankss!!!

I can sell you 4* 74HC4851 for 9 euros (Shipping cost by Regular airmail and fees included).

That's interesting. i couln't find it here for now, i'll look a little more and will contact you by PM. Thanks!!

Would you be able to let us know what you used to drill the holes? Dremel rotary type tool? Regular drill? Drill press? What size bits?

I am following your build with interest!

Thanks Jamdat!
To make the holes we did a two pass job. First pass, i used a needle in a dremel to mark the holes, and second pass, we make the actual holes with a standard drill, i think the bit size was 0.8 mm

[japi]

Update

Today I got some rack and pads, can't wait to finish my build and start playing !!

http://www.japiwebcam.com.ar/japi/megadrum/04-dbdrums/

Tomorrow I will continue making the board, I have all the components to finish the digital board, I will keep you posted here

[japi]

UPDATE

Today we finished the digital board, woa!

http://www.japiwebcam.com.ar/japi/megad ... /index.php

We tried uploading the firmwares with mixed results.

PIC18F2550
Didn't find a guide on how to program it
We tried Winpic as suggested here but always failed in the verification. Later we tried with another program "winpic800" and it went everything ok. The firmware was downloaded from the downloads section. The device is now recognized as a "usb audio device"

ATMEGA32 16PU
As per the instructions in the howto here , we loaded ponyprog up, set up the LPT but the "probe" button always said error. We had a lot of doubts, as the howto only says "program the atmega" but not what buttons to use in the ponyprog.. there are many of 'em.. and we are novices at this PIC thing.. Anyway, tried write program and write data and seem to write ok but we got some errors. Finally, loaded the latest firmware from the forum, and hit "write all" and that did the trick. No errors. . We used ponyprog 2.07.

Right now we don't have the analog board done yet, there's a way to know if everything went ok? How I know if megadrum is working? Also don't have the lcd
We tried the MD32Controller1.1b.zip and I get the screen with the sliders but I don't know how to test the digital board alone, without the triggers.

Thanks

[japi]

I think the 18F2550 programming went ok, but i don't know how to test the atmega without the triggers

device manager:



midi ox

[japi]

Right now we don't have the analog board done yet, there's a way to know if everything went ok? How I know if megadrum is working? Also don't have the lcd
We tried the MD32Controller1.1b.zip and I get the screen with the sliders but I don't know how to test the digital board alone, without the triggers.
Thanks

Nobody?
I'm waiting the 4851's to arrive to make the board
I have the jacks, one 4051 and 2 diodes. Can i try at least one input with these?

[japi]

UPDATE
I hope i'm not alone in this thread

My megadrum is alive!!!!!!!! yeeeeeeeess



Today i got the lcd and the buttons, and finally put everything together! After adjusting the contrast the copyright stuff showed up

More pictures from today
http://www.japiwebcam.com.ar/japi/megad ... /index.php

I'll see if in the following days i can make a test at least with one trigger (I have only two schottkys for now)

[milk]

Hey japi, nice going on the project.
I got stuck trying to record the pic... it seems my pc won't do serial very well.

Since you are in Argentina, where did you get the 4851's?

saludos!

[japi]

Hey japi, nice going on the project.
I got stuck trying to record the pic... it seems my pc won't do serial very well.

Thanks!
Right now i'm trying to figure a short or something that makes the board being recognized at times only

Since you are in Argentina, where did you get the 4851's?
saludos!

I didn't.
I asked in every single electronic shop and seems like is not sold here.
I purchased the 4851s from synthex, i'm waiting the delivery yet

[japi]

Well, my board is oficially malfunctioning
First I had the "disconnecting" issue, ie: the board would dissapear from device manager, and now my lcd displays the first 8 channels with activity and there isn't anything plugged

I'm starting to get frustrated, maybe is time to start from scratch

[gastric]

Troubleshooting is a process of elimination. First, start with looking at anything connected with wires as they're the most likely to suffer breakage from movement. Then inspect the board for anything obvious. Then I'd start double-checking all traces and solder points by using the V2.5 TOP image and checking continuity from the component side. Checking continuity with the component leads would seem most thorough as it checks the component lead, the solder point, and the board lead running to whatever component lead the trace leads to. At least that's what I've been doing in my effort to figure out why I cannot program the ICs.

I've seen a lot of posts related to failure to program the ICs, and even to successfully transfer firmware updates via SYSEX. I'm not sure what that means other than doing these processes isn't as easy as they should be.

But I absolutely wouldn't start from scratch. That's more work than identifying your current problem. And you're likely to just have other, different problems along the way. If I did have to do it all over again I'd just have purchased a V2.7 kit with pre-programmed ICs, skipped the jacks board, and probably have been done a couple weeks ago. That reduces all of the potential issues to soldering and stripping wires.