Is there any difference between the Freetronics eleven and the Arduino Uno R3.
I think that before the Uno R3 the Freetronics eleven might have been a lot different, but now with Uno R3 I think they are similar?
Anyone know?
Yes, they are very similar. The freetronix Eleven has some additional features and costs a little more. I think the main advantage is the prototyping area but that's just me.
The Uno R3 is more flexible if you're into reprogramming USB interface. It has an ATmega16U2 instead of an 8U2, and breaks out an extra four pins.
If you really want to play with USB, then get a board that allows you to play with USB in the sketch
vs having to mess with the USB to serial interface chip. There are many things that are difficult
or not possible to do with either the 8U2 or 16U2 that can be done with other boards that
have an AVR with native USB support.
For USB control, I'd look at:
Teensy: Teensy USB Development Board
Vinciduino: electroFUN LTD: vinciDuino
Leanardo: Arduino Leonardo ATmega32u4 with headers : ID 849 : $24.95 : Adafruit Industries, Unique & fun DIY electronics and kits
--- bill
Actually I'd say USB experimentation is easier with the Uno board. Changing the USB code of a 32U4-based board involves sacrificing the Arduino bootloader, in which case it's no longer an Arduino and cannot run Arduino sketches. It also means you have to merge your program with the new USB code and find some way to make them run together on a single CPU. It's doable, but not especially easy.
On the Uno you can upload LUFA projects (for example) with little or no modification to the 16U2 chip, and still run ordinary Arduino sketches on the 328p chip. It's even possible to run an Arduino sketch on the 328p which updates the 16U2 code, so you don't need an ISP programmer.
tim7:
Actually I'd say USB experimentation is easier with the Uno board. Changing the USB code of a 32U4-based board involves sacrificing the Arduino bootloader, in which case it's no longer an Arduino and cannot run Arduino sketches. It also means you have to merge your program
HUH? Not in my experience. Have you played with a Teensy board?
You don't have to modify the bootloader to use USB on a 32U4.
That is the beauty of having native USB in the AVR.
Once the application code (sketch) gets control, it can program the internal USB hardware directly.
When using the AVR chips with native USB the AVR sketch code (or its USB libraries) has control over the USB.
Interfacing with USB can easily be done with already existing libraries for a sketch just like any other hardware
for arduino.
When doing things like serial emulation over USB you can take advantage of the built in low level
flow control of USB. When the USB control is fragmented/split between multiple chips this is much more difficult
and requires some sort of software handshaking between the 328 and the 16U2 chips.
Not doing flow control can (and often does) mean loss of serial data can occur.
(Just look at all the issues in ArduinoISP)
When using an AVR with native USB support, everything is in the sketch and you don't have to
deal with partitioning functionality across multiple & different processors.
USB interfacing is doable using already written easy to use USB libraries.
It also means you do a single download using the IDE with a single sketch and don't have to mess with
programming any other chip or potentially trashing your USB to serial interface.
Like I said there are many things you can do when the main AVR code has control over the USB
device interface that are difficult or not possible when using a split model.
--- bill
I stand corrected. I've played around with a few of the USB-enabled AVR chips, but hadn't noticed the availability of Arduino libraries to do anything more sophisticated than talk serial over USB. The new libraries make things, as you say, very easy.
It has an ATmega16U2 instead of an 8U2, and breaks out an extra four pins.
Yes, true for the current version of the Eleven. However, the ElevenR3 is on its way: the first thousand have been assembled already, and they'll replace the Eleven as stock runs down. The R3 version has the R3 headers (of course!), microUSB instead of miniUSB, and a 16u2.
If you really want to play with USB, then get a board that allows you to play with USB in the sketch
vs having to mess with the USB to serial interface chip.
To make really small USB devices there's also the LeoStick, which is basically a Leonardo in memory-stick form factor:
LeoStick (Arduino Compatible) | Freetronics
Jon
Sounds good, I'll look out for those. I especially appreciate the crystal clocks on the Freetronics boards, which I use to generate fast-but-accurate timing windows.