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Thomas1426459898

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  1. Thomas1426459898

    SLLogicLogger - A simple logic analyser for the Stellaris Launchpad

    The UART is used and is mapped through the "debugging Stellaris" to CDC/USB. This communication path ist not very fast but it matches the concept of SUMP.. sampling is done to RAM and in a next step is transmitted over serial to a PC.
  2. Thomas1426459898

    Interfacing Stellaris Launchpad to CAN bus

    Hi, I've played around with the CAN module of the Stellaris controller on the Launchpad. To connect the Stellaris Launchpad to a CAN bus, an external CAN transceiver is needed... but only a few wires are necessary. See the attached circuit diagram. Some further details about my experiments: http://www.fischl.de/arm/can_bus_interface_for_stellaris_launchpad/ Thomas
  3. Thanks! I've created a new thread in the Project folder: http://forum.stellarisiti.com/topic/418-sllogiclogger-a-simple-logic-analyser-for-the-stellaris-launchpad/
  4. Hi, Here is my last project with the Stellaris Launchpad: SLLogicLogger - A simple logic analyser for the TI Stellaris Launchpad. Logic levels on PORTB are sampled with 10MHz to RAM (16 kBytes) and then transmitted through the debugging controller over USB to a host computer. No additional hardware is needed - a pure Stellaris Launchpad connected over the debug-USB to an PC is enough. The firmware implements the main functions of SUMP, a serial protocol for logic analysers. There are some clients which supports SUMP. I used LogicSniffer OLS (http://www.lxtreme.nl/ols/) which is a multiplatform Java client. A simple OLS profile file is sufficient to read out the sampled data from the Launchpad. Sampling starts on any state change on PORTB, no further trigger functions are supported yet. Further description and download: http://www.fischl.de/arm/sllogiclogger_logic_analyser_for_stellaris_launchpad/ The logic states are sampled from the GPIO to an array within an for-loop: // sampling buffer char buffer[BUFFERSIZE]; // aquire data for (i = BUFFERSIZE; i != 0; i--) { buffer[i - 1] = GPIO_PORTB_DATA_R; } With this method I get 10 MHz sampling rate at 80 MHz system clock. Does anybody know, if there is a chance to speed it up? E.g. using AHB, uDMA, ...? Thomas
  5. Thomas1426459898

    How fast is the IO?

    Interesting topic! I played around with the other direction: reading fast as possible from GPIO and save the values to RAM (see project description http://forum.stellarisiti.com/topic/335-open-nov-dec-2012-stellarisiti-project-of-the-month-contest/?p=1972). I got a maximum sample rate of 10 MHz. Perhaps some of this hints are also useful for reading GPIO instead of toggling!
  6. Here is my December project: SLLogicLogger - A simple logic analyser for the TI Stellaris Launchpad. Logic levels on PORTB are sampled with 10MHz to RAM (16 kBytes) and then transmitted through the debugging controller over USB to a host computer. No additional hardware is needed - a pure Stellaris Launchpad connected over the debug-USB to an PC is enough. The firmware implements the main functions of SUMP, a serial protocol for logic analysers. There are some clients which supports SUMP. I used LogicSniffer OLS (http://www.lxtreme.nl/ols/) which is a multiplatform Java client. A simple OLS profile file is sufficient to read out the sampled data from the Launchpad. Sampling starts on any state change on PORTB, no further trigger functions are supported yet. Further description and download: http://www.fischl.de/arm/sllogiclogger_logic_analyser_for_stellaris_launchpad/
  7. Thomas1426459898

    What arm-gcc toolchain are you using ?

    I followed the tutorial on http://www.jann.cc/2012/12/11/getting_started_with_the_ti_stellaris_launchpad_on_linux.html to install this toolchain on linux/ubuntu. It compiles the "Stellarisware" with its demos and examples without any problems. But I've no further experiences with it.. I just played around with small test programs yet.
  8. Thomas1426459898

    LM4F120 CAN peripheral

    I also used the MCP2551 to connect a LM4F120 (on the Stellaris Launchpad) to a CAN bus. It's really simple.. just connect the TX and RX lines to the MCP2551 and set the proper pin configuration in the simple_tx example (I used PE4/PE5 for the CAN0 module). Here is my mini-howto: http://www.fischl.de/arm/can_bus_interface_for_stellaris_launchpad/
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