A few noob questions...

[ignotus]

Hi there!

First of all thanks Dmitri for sharing your project, it looks really good!

I've been following the progress here for a while, gathering parts... but things have developed so fast that it's been hard to keep up! Synthex has made some very interesting contributions!

Anyway, as I said, I started putting components together some time ago, and then things got changed (I said 'Great!', put the bat85's aside and got some IC diode arrays), and then things got changed again (all for the best, I know ), but those 4051 replacements were a little hard to come by around here... so I decided to stick to Synthex's first all-in-one PCB design.

Right, here are my noob questions before I start on it:

1. For the 1uF caps: can I use electrolytics for the 3 of them? (it's what I've got lying around)

2. I don't need midi i/o; I know this has been dealt with, but just to get it straight, the components I don't need are:
-optocoupler
-3 x 220 ohm resistors
-1x 1N4148
and the rest stays the same, right?

3. They don't have 6k2 resistors at my local shop, they tell me that standard is 6k8 - will this do?

Thanks again and keep up the good work!

[dmitri]

1. For the 1uF caps: can I use electrolytics for the 3 of them? (it's what I've got lying around)

Yes, you can as long as you connect "-" to ground and "+" to Vcc

2. I don't need midi i/o; I know this has been dealt with, but just to get it straight, the components I don't need are:
-optocoupler
-3 x 220 ohm resistors
-1x 1N4148
and the rest stays the same, right?

Right. Plus you won't need 4k7 R26 resistor.

3. They don't have 6k2 resistors at my local shop, they tell me that standard is 6k8 - will this do?

It will but it will make gain level change slightly more narrow. You can use 4k7 and 1k5 resistors sequentially connected.

[ignotus]

Thanks Dmitri for the quick reply!

Ok, now that's sorted I'm off to the store to get some missing parts - and then it's soldering time!

Hopefully I'll be able to give you some feedback in the near future!

Cheers!

[Synthex]

but those 4051 replacements were a little hard to come by around here

Where do you live ?

[Synthex]

Ok, now that's sorted I'm off to the store to get some missing parts - and then it's soldering time!

Have you ever realized the PCB ?
Thanks.

[ignotus]

Where do you live ?

Hi Synthex - I live in Spain.
The thing is I'd have to order those parts and postage costs would be far greater than the components themselves - and I'd be stuck with a load of unwanted parts I already bought - so what the heck, it's not that much of a difference...

Have you ever realized the PCB ?
Thanks.

Unfortunately, no. I can't do it myself (I have enough on my hands without getting into that; I'd love to though...) so I took a print of your design down to an electronics store... and they just couldn't get it right (they gave it 3 tries and the result was crap, so they gave up. I really don't know what the story was, whether they're useless or what).
SO, what I'm doing is just lifting the layout from your PCB design, expanding it a tiny bit, and doing it on experiment board. I just did the digital part and I'm knackered. But it looks promising, so far so good . I'll see if I can hook it up sometime this week and give it a few whacks (the pads, not the module! ), see what it sounds like.
I'll keep ye informed.

Cheers!

[ignotus]

Hi

My progress so far (pics will have to wait till I can get hold of a camera ):

I managed to build an all-in one megadrum32 on perforated board, using the deprecated design with the diode arrays - it's quite crammed and a PCB would definitely have been easier.
I set up the isp cable for the atmega, ponyprog said that write was successful... but nothing happened on the lcd screen, I spent a while checking for shorts. errors, the usual... but then I happened to read the small lettering on the atmega... and I was given the wrong one - ARRRRGGHHHH!! it'a an atmega16, so I suppose that's one good reason why nothing was happening. It's really frustrating, because now I'll have to wait for the right one, and there was a brand new firmware release...

[dmitri]

When you programed your Atmega16 did you select Atmega16 or Atmega32 as a target device in PonyProg?

[dmitri]

You may try this firmware on your Atmega16(it's 22 inputs version):

megadrum16_16.hex

[ignotus]

Cheers Dmitri -that's quick!

I built a 32 channel version - will this firmware work?