on synthex scheamtics things I can remove

[whiskey29]

Hi Synthex and Dmitri

I want to prepare my next project after the DIY drum is done,
I could use the time I have now to hunt for parts.
I want to attempt to create megadrum based on synthex schematics.

I already have working megadrum from Dmitri and one for my brother.
But seeing pictures people posted, now I want to have one build by myself.

I have to get the pic and atmega from Dmitri right ?

And on synthex's schematics,
Can I ommit both ICSP connection since the chips are preprogrammed?
Can I remove the 5volt regulator circuit if I were to get the power directly from USB ?
Can I replace the resistors and caps to the closest value if I cant find them ?
And I can just cut down the inputs by ommiting the U6-U11 right? And by doing that the pin 33-40 on atmega will connect to nothing if I were to reduce the inputs?
And I should keep the crystal and caps closest to the IC it self right ?

Thanks in advance
Even just to think about it, excites me

[Firelord]

I have to get the pic and atmega from Dmitri right ?

Only ATMega.

[dmitri]

Can I ommit both ICSP connection since the chips are preprogrammed?

You need ICSP to program PIC.

Can I remove the 5volt regulator circuit if I were to get the power directly from USB ?

Yes

Can I replace the resistors and caps to the closest value if I cant find them ?

You'd better not unless you know what effect a different value will have.

And I can just cut down the inputs by ommiting the U6-U11 right? And by doing that the pin 33-40 on atmega will connect to nothing if I were to reduce the inputs?

Yes, you can exclude unneeded MUXers.

And I should keep the crystal and caps closest to the IC it self right ?

Correct.

You can also exclude 6n138 and associated parts if you're not going to use MIDI In port.

[whiskey29]

Hi Dmitri, Thanks for the reply.

What if I put two resistor in serial to achieve same value? That would work right ?
On the PIC, in case if I cant find exact one, I can get it from you Dmitri?

[dmitri]

Hi Dmitri, Thanks for the reply.

What if I put two resistor in serial to achieve same value? That would work right ?

Yes

On the PIC, in case if I cant find exact one, I can get it from you Dmitri?

I don't have or use any chips in DIP packaging but if you were to get an Atmega
chip then I can probably order this PIC for you as well.

[whiskey29]

YESSSSSSS If you are willing to order the PIC as well, that is a huge help and may be 74HC4851 as well
Is the PIC and multiplexer have replacement similar parts ?
I went the electronics are in Surabaya(town I live, Second biggest here), and I cant find the PIC and the 74HC4851.
I havent try to look for them in Jakarta(the capital), but I have to do it together with my trip next time.


In the mean time, I will design and etch the PCB first. Once its near ready I will let you know

Thanks a lot Dmitri

[dmitri]

YESSSSSSS If you are willing to order the PIC as well, that is a huge help and may be 74HC4851 as well
Is the PIC and multiplexer have replacement similar parts ?

For PIC see viewtopic.php?f=3&t=702&hilit=pic18f14k50
For multiplexers it is 4051, the ICs used in the original Analogue board schematic: http://www.megadrum.info/content/schematics but you will need BAT85 diodes and protection resistors.

[Synthex]

If you want, I can provide you the programmed PIC18F14K50 and 74HC4851, all in DIP format.

[whiskey29]

If you want, I can provide you the programmed PIC18F14K50 and 74HC4851, all in DIP format.

Yay Thanks for the offer if the PIC is preprogrammed, I can remove the ICSP part
To save shipping, can I get the Atmega in DIP from you too ? (If Dmitri doesn't mind)
I don't mind give a donation for the project as if I'm buying a kit The money is better spend for that, rather being used as extra shipping
(shipping for atmega and shipping for pic and multiplexer).

I have checked the price for the IC's from farnell, its qutie cheap actually. But shipping is the most part for the bucks.

Dmitri: I just look at the original schematics, is the 4051 is 74HC4051 ? I have used that ic for binary clock,
but BAT is no where to be found and I have been avoiding circuits with BAT for a while now

By the way, the total I spend for C, R connectors all without the ATmega, PIC and 4851, is about USD15.
LCD is the most expensive part about USD8.

[Synthex]

To save shipping, can I get the Atmega in DIP from you too ? (If Dmitri doesn't mind)

Yes, you can. (If Dmitri doesn't mind)