Turning the Stellaris Launchpad into a logic analyzer

acquisition

If you have a Stellaris Launchpad sitting around, have a go at using it as a logic analyzer

The Stellaris logic analyzer is based upon this earlier build that took code from a SUMP comparable Arduino logic analyzer and ported it to the much faster and more capable Stellaris Launchpad with an ARM Cortex 4F processor.

This build turns the Launchpad into a 10 MHz, 8-channel logic analyzer with a 16 kB  buffer comparable with just about every piece of software thanks to the SUMP protocol. Even though the ARM chip in the Launchpad isn’t 5 Volt tolerant, only pins 0 and 1 on Port B are limited to 3.6 Volts. All the other pins on Port B are 5 Volt tolerant.

Not a bad piece of work to turn a Launchpad that has been sitting on your workbench into a useful tool.

20 thoughts on “Turning the Stellaris Launchpad into a logic analyzer

    1. If you’re interested in keeping jitter (basically, not distorting the timing of the signals) to a minimum, as you generally do when using a logic analyzer then you would not use a level converter/re-driver.

      1. I think this depends on how much you spend for the translator :D
        Though it is worth a try, even if it’s to find out if it will work as intended of have noticable failures. Sadly i only have 1.83.3V translators or i would’ve tried out on my own.

          1. The HAD page code interprets those symbols as a (broken) HTML tag and skips them. I hope there’s some way to add an escape code to show them, never tried though.

  1. This is awesome. I couldn’t justify the $150 for Saleae since I’m just playing around with this stuff, but $5? No problem! I already have a Launchpad sitting unused on my desk! Thanks for this!

    1. This is to be expected: the code appears to make absolutely no attempt at sampling at regular intervals. Instead it just uses a for loop and hardcoded “samplerate” that is not accurate. Considering this device has DMA and everything, it could be written much better. And run-length-encoding would make it a lot more useful..

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