si570 breakout fun

In researching SDRs, I discovered that a very popular chip that is used to provide accurate variable frequencies is the Silicon Labs' si570 XO chip. This little dandy has a low additional parts requirement, and is controlled via I2C. I managed to get a hold of a sample and I intended to try and mount it on a breakout board (in fact, this breakout board). Unfortunately, I was unable to get the SDA and SCL pins to solder correctly for me to the point that I could control it. I would power it up, and there is the factory-set frequency being generated on the CLK+ pin like you would expect. I would then hook up a Bus Pirate and try and interrogate for I2C devices, and nothing is discovered.

So I scotched that breakout board, flipped the chip over, and attached it using right-angle 1mm pin connectors to some protoboard. After powering it up with the Bus Pirate, I was able use it and detect the default I2C addressess for the si570. I'm now at a place where I can now play around with this guy with the MSP430 and LPC810 chips.

Here is the initial take, prior to adding pull-up resistors for SCL and SDA.

And the after-pic:

I'm thinking of using this chip in a comparable way to the Tenna Dipper, allowing me to figure out the resonant frequency for antennas for a wide range of bands (I'm guessing  anything from around 7 MHz to 300 MHz with this particular version of the si570; higher frequencies with different variants).

Additionally I would like to maybe use it as the oscillator with some simple filters to create some simple transmitters.

I also would like to maybe explore building my own Tayloe detector/mixer.

Too many things to do, too little time!

LPC810 ARM Processor board

So apparently I'm very distracted by shiny things. I received a little while back the LPC810 starter kit from Adafruit [1]. And while I was working through their little tutorial [2] on setting up build chains and gettting the Hello World blinky to work, I was really just annoyed with the breadboarding of it, so I decided to make it a bit more permanent. I ended up putting it all on some protoboard with breakout headers, an ISP header row for the serial cable, an ISP jumper for programming, the 3.3V power regulator and caps provided by Adafruit, and a simple power LED indicator. It works like a champ, although I am thinking I might add a pinout for ground and the +3.3 pins so I can swing power out.

Here's its obligatory picture

Update: I went ahead and added the proposed headers, as well as a simple little jumper to allow the running of the Hello World Blinky delivered with the microBuilder LPC810 codebase [3]. Here is the new obligatory picture!

Update: I can't stop myself; I ended up adding a button tied to reset so I wouldn't have to keep pulling the programming headers to cut power each time I wanted to reprogram it. Final iteration:

I also downloaded the generic launchpad ARM binaries so that I could build things without using the LXPresso IDE [4]. I also found some small little sample projects that had no reliance on any external LXP libraries [5]. Just tweaking the included makefile, I was able to compile their little blinky programs and load them using FlashMagic (I need to spend a little time and set up automatic commandline flashing as well) [6].

[1] - http://www.adafruit.com/products/1336
[2] - http://learn.adafruit.com/getting-started-with-the-lpc810/introduction
[3] - https://github.com/microbuilder/LPC810_CodeBase
[4] - http://lpcxpresso.code-red-tech.com/LPCXpresso/
[5] - http://www.midibel.com/
[6] - http://www.flashmagictool.com/

I am the very model of a modern major general...ham

Summer has been busy with vacations and work, so I've not been able to really play around much. However, I did recently upgrade my amateur license from Technician to General, which opens up a much wider range of frequencies to play around with. To celebrate that, I have gotten a couple of toys with which to play around. These include the very impressive FUNCube Dongle Pro + [1] and since I have new privileges, the Ultimate QRSS 2 multiband QRSS/WSPR transmitter [2]. We'll see if I can actually get out of my house with that; my location apparently is a black hole for all forms of reception/coverage. While I have several plug-in band filters for the U2, I've only assembled the ones for 20m and 30m, and up till now, I'm not seeing anything coming out, so I have some debugging to do....

Obligatory picture of the assembled U2

[1] - http://www.funcubedongle.com/
[2] - http://www.hanssummers.com/ultimate2.html