Protocol Disappointment

I ran into some headaches with electronics tonight. First, I tried to get recognizable data out of the Honda Music Link, using most of the hardware mentioned last night. Unfortunately, this didn’t work out as I hoped. While the PIC and NEC-branded IEbus controller communicate via SPI, a Control / Data line is also used. This means that the data I sniff in either direction could either be control or data, and without knowing the state of that line it’ll be even harder to figure out the protocol.

I’m thinking that the best thing to do (if I want to continue the project) is to pick up a PIC with two SPI lines, so I can read both of them into buffers at the same time. Then I can also check the status of C/D, bundle all this together, and easily output it to the PC, already in a somewhat readable format.

Or, I can just stop working on the project again.

After getting frustrated with that, I decided to tear into the Xbox 360 Chatpad (photo gallery retired) and see if I could figure out what it is spitting out. Well, the short answer is that I couldn’t. I was able to see something, but I’m not sure what it is. (Screenshot of data being captured.)

The serial data is 0-2V when coming out of the 360, and it appears to do some regular polling, back and forth. I couldn’t figure out the baud rate and whatnot, so I couldn’t really tell if what I was seeing was valid data or not. That said, it’s a start.

Here’s two more photos:

· Test leads connected to Chatpad.
· Detail of leads soldered to internal Xbox 360 Chatpad connector.