01-08-2009

The RF portion is now complete. The component on the left hand side of the image below is a Analog Devices ADC4360 synthesizer running at 870 MHz and serves as the local oscillator to jump down to our first intermediate frequency. One leg of the output is used to drive the transmitter and the other …

01-06-2009

A nudge here, a tweak there, and slowly but surely the layout comes together. I’ve removed a couple of things (most notably the logic analyzer connector) to make routing a bit easier and bumped up to a six layer board. Having a header to connect the logic analyzer is a nice to have feature but …

01-05-2009

Merry New Year! Well I’m back after a two week winter break. It was weird taking so much time off and utterly unproductive so I’m glad to be back at work. 🙂 Today I’m working on the main board that the receiver and transmitter boards plug into. This is the board with the ARM, ADC/DAC, …

12-18-2008

Alright, well I’ve written my DMA configuration macros for the ARM (I don’t like ST‘s library) and I have simple DMA transfer to the SSP working! That was pretty easy. Next trick is to get it running continuously and pinging me back with an interrupt when a buffer is complete.

12-17-2008

Today I’m going to work on getting the final piece of the ARM firmware settled: DMA. Right now, I’m acquiring samples from the SSP manually but I won’t be able to process data if I’m wasting all my time grabbing samples so I need to pass that task to the DMA controller. The unknown at …

12-10-2008

Final exam day. They say the waiting is the hardest part. 😐 Update: 1:32 PM Well that was easier than I thought. I finished early so that’s a good sign. We’ll find out how I did once he posts the solutions online. Grades are due on the 15th so hopefully I’ll know my final grade …

12-08-2008

Not much to post today. I spent most of the day tracing down little bugs here and there. There was a interesting bug where small, seemingly insignificant code changes would sometimes cause the compiler to push some registers onto the stack, changing the amount of time it would take to perform a computation because of …

12-05-2008

It slipped my mind that using the dot product yields the absolute value of the angle difference and we care very much which vector leads of lags the other. No matter, cross product to the rescue! Because the cross product is anti-commutative, the sign of the resultant vector will tell us if the angle difference …