View Full Version : Loading propeller from USB data logger

09-18-2007, 07:50 PM
I recently got the USB data logger (FTDI Vinculum chip) connected and working with my propeller. This is a very nice little addon!· It provides a DOS like prompt for reading, writing and managing files and directories on a USB flash drive.· With all that space available now I'm wondering, has anyone written a loader (like femto basic) to work with the vinculum?·

Mike Green
09-19-2007, 08:11 AM
It's a little more complicated than you might think because you need the loader to be running in assembly language in its own cog because it has to be able to fill most of hub memory with the program being loaded. It can probably be made to work more easily using SPI rather than serial I/O because SPI is clocked and the Vinculum can easily wait for the Propeller cog to process a byte. With serial, even though RTS/CTS is available, the Vinculum might not stop instantly when RTS goes false and the Propeller's serial routine would need to be able to handle this.

I'm using the Vinculum (VMusic2) for a project, so I'll be pretty comfortable with using it by the time the project is done in a few weeks. I've got some other stuff "on my plate", but a Vinculum-based loader is somewhere on the list.

09-19-2007, 08:39 AM
It sounds like you've given it a lot of thought. I am using SPI for the interface on this project. My thought was to first learn how the femto basic loader works, then work on trying to get it going from there. At this point it's not the focus of my project, but I may have to make it so. The complexity of my current goals may neccesitate the loading and unloading of various programs that communicate via some configuration info stored in files.

09-27-2007, 03:45 AM
I have posted my version of an interface object for the Viniculum chip to obex.parallax.com

I'm open to improvements!