Board will now run in stand alone mode

A project log for Stepmotor Driver Board for TI Tiva Launchpad

Three axis stepmotor driver, limit switch conditioning and power supplies.

BharbourBharbour 11/08/2015 at 00:100 Comments

I was having problems getting the MCU to run without the debugger connected to the development IDE. After some digging around, it turned out that the vector table was not in the ROM code. I located a startup file from one of the example programs and carved it up to match my interrupt usage, and now the system will start up and run if not connected to the debug environment. I am using an older version of the Code Composer Studio (5.4) and it refused to generate the startup file when creating a new project. Hopefully the newer versions are better behaved in this respect.

There is a 5V regulator on my driver board to supply the Launchpad board power. It's a little quirky, in that you have to install a jumper if you want to run the system without a USB connection. The Launchpad boards are very USB centric, so they expect to run from the 5V VBus power on the USB debug connector. That VBus rail is brought out on the expansion connector, but back feeding the USB hub would likely cause problems, so there is a jumper to disconnect the on-board power from the VBus rail when using the USB connection.

The 32K boundary issue seems to have disappeared by magic. Adding the vector table and framework for the Non-Volatile-Memory operaion pushed up through the 32K bound and it loads and operates fine.

My day job is starting to get intense again, and so work on this project is going to take a back seat.