Memos From the Cube

Late last week a new package arrived on my doorstep, containing the new product lineup from AVROpendous. Matt has always been very generous with sending me samples of his new hardware, and I can’t say no to packages (although, on occasion, they so no to me and end up flying around Belgium for not apparent reason).

The three big contenders in the consumer USB AVR market (making USB AVR based boards for hobbyists and experimenters) are AVROpendous with the Opendous boards, PJRC with the Teensy boards and of course Atmel with their official USB AVR evaluation boards. This is a great step forward, since a year ago two of those didn’t exist, and USB AVRs were the realm of commercial enterprises with lots of time and money on their hands.

Of the two smaller companies, AVROpendous and PJRC have been engaged in somewhat of an innovation war, trying to grab customers from the same limited market. As such they have taken slightly different directions; Matt, with the open source/open hardware AVROpendous, appeals to the open source crowd. On the flipside, Paul over at PJRC has been trying to win over the novice crowd with the Teensy and its “HalfKay” bootloader, has a closed design but open source (except for the bootloader).

From the beginning, the designs of the two were very different: AVROpendous V1 had an innovative SIL layout, inserting vertically into a breadboard for maximum space savings, while the Teensy had a DIP layout similar to the old – and entirely useless – BASIC Stamp. Since then AVROpendous has also brought out the AVROpendous Mini, a smaller board which used female sockets instead of pin headers and so was wired to a breadboard rather than inserted into it.

Now it’s time for the next wave of designs. PJRC has brought out the Teensy++ sporting a larger ATMEGA32U4 AT90USB646 microcontroller, while AVROpendous has gone for a similar DIP design but with four different versions.

First up, is the tiny AVROpendous-DIP, essentially a clone of the original Teensy – although it has seperate buttons for HWB and RESET rather than the Teensy’s single all-in-one button. I liked the combined button of the Teensy for its super-ease-of-use while programming but found it limiting when I just wanted to reset the AVR and not reprogram it, or just have a “Do Something” hardware button prewired onto the board. This version of the AVROpendous uses the same AT90USB162 microcontroller used on all previous AVROpendous boards, plus the original Teensy.

Second is the interesting AVROpendous2-DIP, which is a slightly larger version of the board mentioned above, due to its use of the newer ATMEGA32U4  microcontroller. This is my first ATMEGA32U4 board and so I’ll be happy to finally have a test-target for the U4 series USB AVRs. Due to space constraints Matt’s used the smaller pin header layout for the JTAG which no one can easily use — unless you got the adapter in the Atmel Raven kits, that is. Got to love free hardware!

Thirdly is one board Matt didn’t send me, the AVROpendous-3D, because it is a subset of the largest board. Sporting a AT90USB646 microcontroller, it provides plenty of FLASH space, a normal JTAG layout and device-only USB operation for the development of complex USB peripherals. This is the same AVR model used on the new Teensy++ board.

Finally is the last board in Matt’s package to me, the AVROpendous-3H. This is the superset of the 3D above and contains a AT90USB647 microcontroller, and so provides USB Hosting capabilities. This board is unusual for two reasons; first, it’s the first non-Atmel general USB AVR board to offer a USB AVR that supports USB hosting mode, and secondly, it contains two USB connectors. The first connector is the standard mini-USB B connector on all the other Opendous/Teensy/USBKEY/etc. boards, but the second is a full-size USB-A connector mounted right on the board. Rather than have the user work out where to get a mini-USB a to USB-A converter cable, Matt decided to just put a second connector on the board for USB hosting and have a jumper select between the two. It’s an unusual move, but after using it for a while I have to say it’s more convenient than the USBKEY, as it means that the mini-USB B connector can be left into the host for reprogramming and powering the board.

All in all, an impressive lineup. Matt’s busy working on porting his AVROpendous package to the latest LUFA release, so users of his boards stay tuned! As mentioned, this month’s release holds the last of the major API changes, with future releases focusing on preserving backwards compatibility. If you haven’t already upgraded, get to it already!