This was a fun and short little project that I’ve recently updated. If you’re thinking about building a cheap signal generator that’ll work to 20 MHz or so, and would be DDS (direct digital synthesis) based, take a look at this:
http://www.frankvh.com/dds-signal-generator.html
It works pretty well.

I had a need for a cheap, quick & not-so-dirty signal generator [...]

Over on AVRfreaks there are a lot of code snippets describing how to connect an AVR to a character LCD display, such as a standard HD44780-compatible display. But not a lot talking about how to do the same using an Xmega.
For a small project I’d been working on, I had an LCD display connected [...]

Time marches on and we’ve had to perform a new PCB revision for the board containing the Atmel Xmega part. So I had the opportunity to add an external voltage reference to the chip. This was one of the things I recommended considering in my last post.
There are some constraints. We wanted the reference’s voltage [...]

I’ve been working with the A/D converter on the Atmel Xmega AVR processors, and it’s been quite the handful. At this point in time (Jan 2010) the parts have some very serious issues, and I’ve lost a lot of time trying to get them to work as advertised. This posting is to share what I’ve [...]

Atmel kindly gave me an Xplain Xmega board at one of their Xmega seminars. It’s a useful tool for ATXmega development, but it does have a couple of problems. I thought I’d mention the ones I’ve tripped over, in case anybody else sees the same problems.
Board Doesn’t Restart Properly
I’ve found that when the AVRISP2 programmer [...]

This is a surprisingly common question.  When using WinAVR, how do you get printf() working on an Atmel Xmega processor?  Hopefully this post will help explain how.
First of all, this documentation page has some good information regarding the different flavours of WinAVR printf:
http://www.nongnu.org/avr-libc/user-manual/group__avr__stdio.html
Note the existence of the printf_P() function, which makes it easy to work [...]

A little while ago I wrote about implementing fast JPEG encoding on an Analog Devices Blackfin. See the original post here:
Blackfin Fast JPEG Encoding
Since then I’ve moved to a new hardware platform, with a different blackfin processor and a different image sensor, which has caused me to revisit this code. I found that with the [...]

Recently I’ve been doing some Atmel AVR Xmega work. The Atmel website says that their low-cost programmer, the AVRISP2, can be used to program an xmega device. But their (current) documentation would appear to tell a very different story. If you read the documentation, you’d reasonably conclude that it wouldn’t work at all.
In fact the [...]

Recently I’ve been doing a lot of embedded uClinux programming for the Analog Devices Blackfin BF537 processor. Writing drivers, application code, things like that. It’s a lot of fun.

One of the things I’d been battling with was finding a reasonably fast JPEG encoder. Now you need to understand that the BF537 doesn’t have a JPG [...]