Arduino and the Si570

I've been wanting to experiment with replacing my little AD9850 DDS modules with the Si570 device. Not out of any sense of dissatisfaction with the former - more out of a spirit of adventure and in preparation for future experiments with extended bandwidth. The big problem with the Si570 - apart from cost - is the package.

I decided to solve the problem by mounting the awkward package on one of my little plug in modules, which start with a small printed circuit board...

Here are a few of the "carrier" PCBs, knocked up yesterday in my "back yard fab", along with an Si570

I got out my little USB microscope and did the best I could with my soldering iron, failing eyesight and shaking hands- here's a close-up shot from the microscope part-way through assembly...

Once the chip was on the carrier, I added some header pins to serve as "legs" for the module, which acts as an 8 pin DIL "wide" (i.e. 0.6 inch) package, which is infinitely easier for me to handle (and, indeed, see) than the original bare device...

Now - I just need to program the thing.

I have driven an Si570 before from a PIC (in my original multi-mode beacon) - that was a pretty brute-force piece of coding. This time I wanted something a little more elegant, so I looked around on the 'net.

The first fruit of that search was the ArduinoSi570 Library , by Gabriel Fournier.

I downloaded that library, but could not get it to compile, either with the provided example sketch or with my own simplified examples. Gabriel quickly and graciously answered an email asking for help - but his suggestion was that I should find another library! So I searched some more...

Fortunately, that search soon reminded me of Farhan's new Minima transceiver, and I found the "Radiono" code for it, which includes library resources for controlling the Si570. I downloaded that library and soon had modified the code (which is intended for the ATmega328P) to run on an Arduino MEGA, which allowed me to confirm that my new Si570 module was working correctly...

My real interest was in getting the new Si570 module running under the control of the Arduino DUE and - I'm ashamed to say - I still haven't succeeded in that goal.

My modified program now compiles and I can see the I2C activity between the DUE and the Si570, but they are not yet successfully communicating.

You can see how much I'm struggling by the presence of an empty coffee cup in the frame below - things are obviously bad...

I guess it won't be long before we have Si570-derived RF for the Arduino SDR - but not today!

...-.- de m0xpd