Well, sorry that I haven’t posted lately, but I’ve been really quite busy. I’ve had quite a bit of success and the mp3 player project has gone through several key changes.
First, and most importantly, I’ve successfully (and reliably!) interfaced to the SD card. This took some work. On the breadboard pictured in one of the previous posts, I was getting some strange interference on the data line of the SD card. Because of this, I decided to switch to wire wrapping for my prototyping. It’s my first time wire wrapping so its still a bit sloppy, but is still leagues ahead of the breadboard in terms of expandability and neatness. After a few more headaches, I realized the problem; the first couple hundred bytes of my SD card are 0x00. I chose a more suitable address to read and it appeared to be working. After a few more tweaks it was reading consistantly and I was able to bump up the peak rate to around 305Kb/s.
Now I am on to the challenge of writing a FAT16 driver. Expect another post on details of this in a day or two.