MegaDrum 56 inputs latest schematic and PCB

[cschlipp]

Okay, thanks.

Previously I've found your post saying only 10µH to 1mH, so I was a bit confused.
Just have to wait for my 4851s to start drumming...
Thanks for this project!

[oskar]

the solder of the poles of electrolytic capacitor 10uf is this:
positive pole in the CN7
negative pole in the 6N138N

or

positive pole in the 6n138n
negative pole in the CN7

tks

Polarity capacitor, elko, smd :

[oskar]

Here a picture of my 56i push buttons and rotary encoders PCB. The numbers are upside down because I wanted to be able to read them when I look into the enclosure, front facing towards me, and so normally look upside down.
The main reason to build a PCB, for the rotary encoders and push buttons, is the fact that I don't like screw heads on the face of the enclosure and my encoders are ment for PCB mounting. This PCB has no wire jumps (bridges). The numbers correspond with the header pins of single sided 56i design of Dmitri (conn_4 to CN2 / conn_5 to CN3).

[Chunky Kev]

Hi all,

I see from another post on forum I need to use an Atmega 644 with protected bootloader viewtopic.php?f=3&t=1251&start=0 .
Unfortunately I didn't see this until after I bought one from Ebay with its own Bootloader pre-installed. Is there anyway to get the protected bootloader onto my Atmega 644P rather than having to buy another one?

Cheers for any help.

[dmitri]

Unfortunately I didn't see this until after I bought one from Ebay with its own Bootloader pre-installed. Is there anyway to get the protected bootloader onto my Atmega 644P rather than having to buy another one?

No.

[Chunky Kev]

As that is the case, are there any bulk orders still active? most recent one I can see is V11, in 2012? What is price for single chip (atmega 644 20p) uninsured in UK at moment? Can you put link to thread if there is one?

[dmitri]

See prices in viewtopic.php?p=21010#p21010
You can revive the bulk order, start a new one or just order on your own.

[Chunky Kev]

Anyone got a PCB layout for the inputs which uses PCB mount jack sockets and a 40 pin connector. Trying to keep it looking nice and easy to assemble. Any other PCB artwork for switches etc would be good if you have it.

[jjpl2001]

Hi, recently I got a MD644 56 Input workingo with an old firmware. I made a new PCB an changed all the components from the old to the new board. BBut it dosent work

the display shows al triggers and responds to the hits, the usb (18f2550) is working and detected by the pc. the tx pin on the 644 is giving output in the oscilloscopoe, but for some reason toontrack solo sometimes crashes.

I wonder if it has something to do with R3 R4 R5 and R6? the are not exactly the same than in tis schematic. I didnt found the correct so I did put

Schematic Used (viewtopic.php?f=3&t=1623)

R3=1.9k
R4=3.2k
R5=10k (ok)
R6=6.5k

Do this resistors have something to do with Midi send or they are just for voltage reference? Thanks

[dmitri]

Use components values as shown in the schematics unless you know you can use different values. After that test it again and describe the problem if it's still there. 99% chance is you have a short or a break somewhere on the board.