Arduino questions

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Marius,

> I guess you're the same Paul Maddox who wrote the article "MIDI and
> the AVR" for AVR Freaks half a decade ago.

<UGH> was it that long ago?
I feel old..

Yes that was me.

> First of all, I just want to thank you for a great tutorial on MIDI!

no problem, I'm happy to help and share when/where I can.

> The only difference between Diecimila and the Arduino Mini, apart from
> size, is the missing USB interface.

okdoky.

> There also is an Arduino Nano, where they added the USB again
> (http://www.arduino.cc/en/Main/ArduinoBoardNano
> ).

spotted that, nice... but I worry about breaking something so small :-)

> Yep, just replace the chip. The board should be the same, although an
> older revision.
> Note that the older Arduinos have an annoying feature of waiting to
> seconds in the bootloader before they start. This is fixable by
> hacking the bootloader though.

okdoky, I have an AVR programmer around, looking at the schematic I should
be able to fudge a cable and upload a new bootloader.

> As you may have read in another thread, Jay and I are hacking around
> on an Arduino Synth project.

indeed.

> Last week, I hacked together basic MIDI input support (we're using the
> Diecimila):
> https://whatever.metalab.at/user/kintel/Arduino/ArduinoSynth/

looks good to me.

> The code is not pretty at the moment, but you'll get the idea. Any
> insights or suggestions for improvement are welcome :)

For the moment I want to use it to trial some of my whacky controller ideas.
My biggest concerns was speed, now I know it's compiled not interpreted
code on the arduino I'm not that worried. The next concern is IO, I can
see I'm going to end up using some of the midibox digital in/out modules
to expand to what I need.
but I'll worry about that when I get there.

I assume there's an arduino mailing list somewhere (I found the forum), is
there?

> Both RX and TX on the Arduino board come directly from the ATmega.
> However, these pins are also used by the USB2serial chip, so some work
> is needed to make them co-exist. At the moment, I have to disconnect
> the midi optcoupler to be able to use serial over USB. This might be
> fixable by using a weaker pullup on the RX pin.

or, you could break it out into voltage controlled switch type arangement,
so that when you hit 'reset' it sits and waits for data from the USB
serial port, then once that goes 'quiet' for say 5 seconds, it switches to
the RX and TX pins on J1.

With previous projects I've used the Reset line to control a 4016 (or 4066
if I had one) to select the programmer in/out lines when being programmed
(the reset line is held low during ISP) and then reconnect my circuit
afterwards.

Alternativly, you could just add a DPDT switch which keeps it simple and
cheap :-)

All those require a degree of board modding to work though.

> I'm not sure what you're referring to here. The "Arduino programming
> language" is really just C++ (avr-gcc) with some libraries to make it
> easier to use for beginners. Nothing is interpreted. You can look at
> the Arduino board as a normal ATmega developmen board.

for some reason I thought it was interpretted... I must be having a blonde
day.

Thanks for the input and help guys
Paul