tranzport 0.1 oct 18, 2005 arthur@artcmusic.com --- The Frontier Design Tranzport(tm) (www.frontierdesign.com) is a simple wireless USB device. It is not a MIDI device. The document on their web site "Tranzport(tm) Native Mode Interface Description" describes the Tranzport(tm) as if it were a MIDI device, but this is implemented by their Windows and Macintosh software drivers. This code will allow you to use your Tranzport(tm) at a lower level of abstraction. This code relies on libusb, which can be obtained from libusb.sourceforge.net. To compile the program, type "make". You should end up with a executable called "tranzport". You'll probably have to run this program as root. Using the program is straightforward. It will simply tell you which buttons are being pressed and what not. If you press one of the buttons with a light, the light will turn on. If you hold shift and press one of the buttons with a light, the light will turn off. If you take out the batteries to the device (or go out of range), it will tell you that the device is offline. When you replace the batteries (or come back in range), it should tell you it is back online. Once you understand how everything works, you should be able to incorporate it into your own setup however you wish. This code was developed on a Linux machine, but (theoretically) it should work on any system that is supported by libusb, since that is how it communicates with the device. Here are a few more details about the device: There are two endpoints for communication with the device. All data reads and writes are done in 8-byte segments. One endpoint is for interrupt reads. This is used to read button data from the device. It also supplies status information for when the device goes out of range and comes back in range, loses power and regains power, etc. The format of the data is: 00 ss bb bb bb bb dd 00 (hexadecimal) where: ss - status code, 01=online ff=offline bb - button bits dd - data wheel, 01-3f=forward 41-7f=backward Please refer to the source code for a list of the button bits. The other endpoint is for interrupt writes. This is used to toggle the lights on the device, and to write data to the LCD. There are 7 lights on the device. To turn a light on, send the following sequence of bytes: 00 00 nn 01 00 00 00 00 (hexadecimal) where nn is the light number. To turn a light off: 00 00 nn 00 00 00 00 00 (hexadecimal) Here is the list of lights: 00 Record 01 Track Rec 02 Track Mute 03 Track Solo 04 Any Solo 05 Loop 06 Punch The size of the LCD is 20x2, and it is split into 10 cells, each cell being 4 characters wide. The cells progress across, then down. To write to the LCD, send the following sequence of bytes: 00 01 cc aa aa aa aa 00 (hexadecimal) where: cc - cell number aa - ASCII code Here is a list of the cells to clarify: 00 row 0, column 0-3 01 row 0, column 4-7 02 row 0, column 8-11 03 row 0, column 12-15 04 row 0, column 16-19 05 row 1, column 0-3 06 row 1, column 4-7 07 row 1, column 8-11 08 row 1, column 12-15 09 row 1, column 16-19 You should refer to the "Tranzport(tm) Native Mode Interface Description" document for a listing of the ASCII codes the LCD uses.