Latest MegaDrum schematics. 32 inputs.

[dmitri]

And for those who wonders why I switched from DipTrace to KiCad - the main reason is that KiCad doesn't place components/nodes number on a board limit compared to a free version of DipTrace.
And of course a nice 3d preview of a board with components like shown below:)

Digital Board:

digital_board_3d.png

Analogue Board:

analogue_board_3d.png

[andrex289]

Hi dmitri, i think there is something wrong with digital and analog board schematics. The 15th and 16th pins from analogue connector are wired to ground and vcc respectively on both boards... I think these pins just dont do anything, does they?

[dmitri]

They do. They're connected to ground and Vcc. ICs and other parts pick up ground and Vcc from them.

[CairnsFella]

Ok all.. accepting that I am pretty dumb on such matters, I am having problems re the keyboard (button) connectors.

On the schematic, it shows two different connections for the encoders and keyboards. On my (or rather "synthex's" rather excellent) board, I see only the keyboard connector.. BUT, this has 5 pins rather than the schematics 4 ?? I seem to be able to get the buttons to function using pin 5 as the "common connector" (I dont know what the technical term is) but as this doesnt appear to be as per the schematic, I didnt want to pursue this for fear of breaking something....

On a slightly different note, many thanks to synthex, the board is great and.. so far (having connected one piezo to the pins and the board via usb to my pc... it seems to be fully functional

This is despite my almost wrecking the board thinking I had several shorts on the lcd connector, and aggressivly scraping at the solder, only to find that they are meant to be connected

Thanks for any help received.

[Synthex]

All informations, schematics, ... about my v2.7 PCB are here :
http://www.megadrum.info/forums/viewtopic.php?f=3&t=187#p2450

For keyboard :
http://www.megadrum.info/forums/viewtopic.php?f=3&t=187&st=0&sk=t&sd=a&start=60#p3481

[CairnsFella]

Thanks,

Thank second link ties in with what I "discovered" to work.. but I would say that there is info on the site that contradicts.. maybe its for a different set up.. I'm not that "up with electronic" to know for sure, but it is confusing. I cant remember where it was posted, but it only uses for pins for the keyboard and shows the use of diodes on pin 4.

Anyway. no matter, as I am back on track.

Thanks again.

[jamalpiper]

I have a question about the programming cables, Is it at all possible to program the Atmega from a a 9pin COM port? My computer only has that style.

Schematics would help if its possible.

[dmitri]

I have a question about the programming cables, Is it at all possible to program the Atmega from a a 9pin COM port? My computer only has that style.

Schematics would help if its possible.

As far as I know it is not possible.

[horkam]

First of all, this info is absolutely wonderful.

Secondly, can I assume that wattages and voltages on the resistors and capacitors can fluctuate quite a bit or should I stick with specific ones like 1/4 watt resistors and 50vdc caps? Reason I ask is that everywhere I go and search for the parts, I get several of each type with differing voltage or wattage ratings and I get a tad confused

Lastly, regarding the resistors that you list as 4k7 and 3k3 etc. Can I read that as 4.7k and 3.3k?

[Synthex]

First of all, this info is absolutely wonderful.

Secondly, can I assume that wattages and voltages on the resistors and capacitors can fluctuate quite a bit or should I stick with specific ones like 1/4 watt resistors and 50vdc caps? Reason I ask is that everywhere I go and search for the parts, I get several of each type with differing voltage or wattage ratings and I get a tad confused

Lastly, regarding the resistors that you list as 4k7 and 3k3 etc. Can I read that as 4.7k and 3.3k?

You can use 1/4 or 1/2 watt resistors and more than 10vdc caps.
Yes, 4k7 = 4.7k and 3k3 = 3.3k