USB v1.1 support on the MSP430 Launchpad

M-atthias was excited to report about his success is getting USB v1.1 running on the MSP430G2452. He’s currently bit-banging the USB  and using ~2Kb code space. He’s been in touch with Christian Starkjohann who is the developer of V-USB on the AVR. Clock is fed through an 18Mhz crystal. Code is under mecrimus-b-0.1.tar.gz on Sourceforge.

This is pretty big for the MSP430 community and will open up alot more projects on a reasonably priced platform.

- Yes, this is similar to the efforts of V-USB for AVR, but in a very early stage. I am in contact with Christian Starkjohann who wrote V-USB, and he helped me with valuable comments. Thank you !

- For now, Mecrimus-B implements a “vendor specific” do-nothing low speed USB 1.1 device, which essentially only connects and gives back its descriptors, which are quite small. But as this is a test for receiver, transmitter, checksum generation and protocol handling, I am very happy with that yet.

- I feed in clock with an external 18 MHz crystal oscillator; I choosed this so that I can hook up an oscilloscope probe without detuning.

- Memory footprint is 2,5kb now, as there are debug message routines included and an halt-disconnect-and-dump-packet point for unknown requests. USB alone should fit in 2kb code.