Saturday, 22 December 2012

TI Stellaris Launchpad

My Stellaris Launchpad finally arrived the other day. I ordered it back when they were under £4 each several months back. They're now about £10, which still isn't bad.

The example software bundle is over 340MB and requires signing up for an account, along with requesting 'permission' to see the code. The drivers seem to be BSD licensed, but the example programs cannot be redistributed. I also tried to get the popular 'Code Sourcery' GCC compiler they recommend but all I got was login screens and talk of professional versions.

Screw that.

On Github you will find my solution. You can use either the ARM Linux toolchain in the Ubuntu repostories (yes, even for bare-metal programming) or fetch the one built by ARM. No click throughs. No legalese. Just free software. The bits I wrote are even under the MIT license so you can crib away, guilt-free.

So far, the example flashes an LED and changes the colour if you press either of the buttons. I think I'll build up a simple library for GPIO and UART because, you know, that stuff's fun.

Thanks to http://eehusky.wordpress.com/, http://scompoprojects.wordpress.com/ and http://recursive-labs.com/ who gave me some great pointers (although I've used the mildly-insane SCons build system rather than the deeply-insane and incomprehensible Make).

3 comments:

  1. I'll definitely have to check scons out!
    Nice work man!

    ReplyDelete
  2. I'd tried the summon build previously and it built but anything more complex than the blinky example didn't work. The pre-built ones for for not only blinky and the rgb example but also the freertos example. The pre-built compiler tools are from here( running on ubuntu 12.04 ):
    https://launchpad.net/gcc-arm-embedded/4.6/4.6-2012-q4-update/+download/gcc-arm-none-eabi-4_6-2012q4-20121016.tar.bz2

    Thanks.

    ReplyDelete
  3. Yeah, I switched to that toolchain too (see https://github.com/thejpster/launchpad/blob/master/prerequisities.sh). Using Ubuntu ARM Linux one is a nice demonstration of using a desktop OS compiler for bare metal but you quickly get annoyed by not having a C library. I haven't tried the Summon ARM Toolchain because I'm not patient enough to wait for GCC to compile and I don't like clogging up my laptop with GCC build pre-requisites. From what you've said, I won't bother.

    ReplyDelete