Interesting. Carefully written C++ can be as fast as C and often faster because types can be managed more flexibly.

Have you compared the footprint of your library? It is probably a little smaller as it doesn't support multiple serial ports. Is it faster?

The quality of this kind of sine wave is limited by the 8-bit table and the analog reconstruction filter you need on the output of the pwm.

I would be careful about building measuring tools with this approach,

My  implementation of the DDS  algorithm for Arduino has a parameterization of the algorithm that could be adapted for different resolutions and table sizes and comes with some examples of how to smoothly interpolate frequecy and amplitude for <a href="http://www.adrianfreed.com/content/arduino-sketch-high-frequency-precision-sine-wave-tone-sound-synthesis">Arduino music and sound applications</a>

I prefer to have a bigger table and keep all the conditional code out of the inner loop. My NCO code can be found here for reference:
http://adrianfreed.com/content/arduino-sketch-high-frequency-precision-sine-wave-tone-sound-synthesis

It has the interpolation code you need to smoothly ramp frequency and amplitude if you want to make clean music synthesizer out of this idea. I also include the tables to map midi note numbers into phase increment values.

You could just make a 3.3V shield with appropriate power supply from USB 5V (a la seeeduino) and some shields just wont work (or work as well).

I don't use shields because my applications need something much
smaller. I suspect most users of this device want the small speed so things like a small connector for lipo (and the charger electronics)
would be attractive.
I just need a 0.1inch breakout board with the FTDI or sparkfun dongle pinout. I suppose for this the nano pinout could be emulated, but I am not attached to that as I use teensy for most projects.

The boardID concept is definitely needed unless the Arduino leaders
believe there should only be one best standard "Arduino" board for each chip.

"We decided to go for Diecimila because the RFA1 is a mega1281 device and has less ports then the mega1280 used on the mega arduino.  

Here is the current pin wiring, any advice is very welcome, because
we are not sure what to do, whether to sprinkle around with the megaRFA1 ports to match exactly diecimila mapping or keep RFA1 ports intact and bundled. Generally the second level AVR functions generate headaches:
- does some shields use T0/T1 ?
- swap AIN0 and AIN1 to have a PWM at D6 ?
- is ICP at D8  used from anybody?
- MOSI and /SS have now PWM at megaRFA1!
"

Good idea. I would use the seeeduino as a reference.
In particular it is a shame to lose the two extra analog inputs to
the digital ports as you propse.  On the seeeduino they are placed on two addtional pins on the bottom row.

I am using the same development board as you. How can I help without duplicating effort?
I was going to start from the 1281 arduino software port you can find
here: http://sites.google.com/site/arduino1281/

Also, there are so few variations from the atmega1280 code how
can we get the atmega1281 and Atmega128rfa1 conditional
code into the core?

They announced RF4CE certification so presumably prototypes exist.
It takes a while to design and build a board so why not start now? The pinout and recommended circuit are established.

The claim is that
"The Atmel Atmega128RFA1 is available now with a suggested price of $4.78 for 10K quantities."

Anyone planning to build an Arduino IDE compatible board with the new AVR with integrated zigbee?

http://www.atmelroma.it/dyn/products/product_card_mcu.asp?part_id=4692

I am collecting up your feature requests for a board.
My own enthusiasm is for a small footprint like the teensy or nano.
What about these ideas:

Lithium charger and battery socket?
lilypad form factor?

I just posted an announcement of my weekend workshop in Berkeley.

Just a couple spots left for this weekend's workshop.
It is going to be a lot of fun: I just received some new interesting music shields.

Half full already.

Please don't leave your signup to the last minute as I have both a
preference to keep the class small and a constraint on the room size which makes it impossible to accommodate late comers when it is full.

July 24th and 25th


During this hands-on workshop we will survey Arduino platforms, libraries, shields and programming techniques for a broad range of musical and sound applications. We will learn how to synthesize useful wave shapes including square, sine, triangle and pulses, how to manage polyphony and timing and how to playback and record sampled sounds.

We will write software to move gestural data from sensors to synthesis software and hardware via MIDI and Open Sound Control.

We will look at effective techniques for building musical gesture sensors including piezoelectric disk triggering, piezoresistive etextiles for pressure and touch sensing and build examples of capacitive proximity sensing for Theremin-like interfaces.

We will review my extensive collection of augmented instruments and new controllers with an eye to what techniques you can adapt to your own projects.

For more information and to sign up:

http://www.adrianfreed.com/content/arduino-music-and-sound-weekend-workshop-berkeley

Last chance: there are just a couple of spots left for this weekend's workshop.

Interactive Soft Circuits and eTextiles Workshop with Arduino Lilypad in Berkeley, California

Saturday June 26 and Sunday June 27, 2010

"In this hands-on weekend workshop we will cut, sew, weave, knit, felt and layer specialized electrotextiles, conductive threads and conventional electronics to create interactive soft circuits for wearables, musical instruments, jewelry and other responsive systems. We will make e-textile pressure, stretch and position sensors connect them to the Lilypad wearable computing platform and use led's and small speakers for output. We will draw inspiration from my large collection of materials, devices and projects reviewing best practices in commercial, academic and DIY eTextile work."

http://www.adrianfreed.com/content/interactive-soft-circuits-and-etextiles-workshop-arduino-lilypad-berkeley-california

Just got a last minute cancellation for this weekend's class so there is one spot left

Sorry about the $$$. Some years I have sponsors to fund scholarships but it has been a lean year for everyone...
I give short free presentations at various arduino events around the bay area and I will showing things at Maker Faire...

There are 2 spots left now so if anyone was dithering it is time to make a decision!