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dellwoodbu

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Everything posted by dellwoodbu

  1. Worth noting... The floating point unit is single precision. C/C++ language defaults to a double for constants in code (that include a decimal point). Unless you need double precision constants i always suffix all my constants with 'f'. So "3.141f" is more efficient on this machine than "3.141".
  2. It also includes support for the new EK-TM4C1294XL Connected LaunchPad. Out of the box cloud connected. Support with working examples for CC3000 on EK-TM4C123GXL and the new Connected LaunchPad. NFC support on the boost-dlptrf7970abp with both launchpads Built in support with examples for the QVGA 3.5" Kentec BoosterPack on the new Connected LaunchPad. Built in support and example for the boostxl-battpack Battery Booster. Probably missing some other good stuff that i am currently forgetting as well. Dellwood.
  3. If you choose to use Code Composer and are new to MCU's then the LaunchPad workshop is a great resource as well. http://processors.wiki.ti.com/index.php/Getting_Started_with_the_TIVA%E2%84%A2_C-Series_TM4C123G_LaunchPad?DCMP=tivac&HQS=TM4C123G-Launchpad-Workshop Dexter
  4. I suggest connecting the center pin to the outside pin. This way if the switch is to the left it is still "off" for your application. If you connect the outer two then the switch will always be "on". Also look at adding the two resistors to PB0 and PB1 so you can monitor VBUS and ID with the USB peripheral. Be aware this could put 5V on the boosterpack pins that aren't normally getting that much voltage. Dellwood
  5. The transistors have 10 k built in series and pull down resistance. If you are using PF1 - PF3 as an output no action is required. If using as an PF1 - PF3 as an input you need to evaluate if your drive signal can overcome the pull down resistance created by the transistor built in resistance.
  6. start with the launchpad workshop http://processors.wiki.ti.com/index.php/Getting_Started_with_the_TIVA%E2%84%A2_C-Series_TM4C123G_LaunchPad?DCMP=tivac&HQS=TM4C123G-Launchpad-Workshop Chapter 10 covers the display and graphics library. The workshop has lots of other good stuff as well.
  7. Spoke with TI on this the other day and they expected to clear the remaining back-orders and have units in stock by early September. Original EK-LM4F120XL shows still in stock at $9.95 on the TI eStore. Dellwood
  8. Lm flash programmer has an unlock feature. Far right tab. Use fury class for 1968 device.
  9. John, This was a known problem with the REV A boards. On REV B the connector moved out closer to the edge of the board. The problem was that with the connector mounted in the flare of the SMD connector would float and cause the whole connector to lift in re-flow. By moving the connector out the whole connector sits more flat to the board and makes a stronger bond. Even on REV B it is not a super strong solder joint care and gentleness encouraged. If you have solder equipment a bit of extra solder on the outside of the SMD housing could be a good idea. Don't use too much or it w
  10. You can use the LaunchPad to program standalone chips that you purchase and install on your own PCB. There is a how-to at http://processors.wiki.ti.com/index.php/Stellaris_LM4F120_LaunchPad_Debug_How_To I'd suggest putting a standard ARM connector on any board you create and interface that to the pins on the LaunchPad http://www.keil.com/support/man/docs/ulinkpro/ulinkpro_hw_if_jtag10.htm This is what the programmers from Keil, IAR and others use this gives you flexibility if you want a different "standard" programmer later. The chip you buy from TI will identical to the chip on the
  11. http://e2e.ti.com/support/microcontrollers/tiva_arm/f/908/p/266853/942510.aspx#942510 TI posted updated code for the MPU9150.
  12. dellwoodbu

    UART problem

    I have not tried this personally. However, you are using UART0 which is connected to the ICDI microcontroller. The baud rate therefore must match between the ICDI microcontroller and the target. It is possible that the ICDI is not correctly changing its baud rate to match the settings in PuTTY. At a minimum the ICDI will come out of reset or power up with settings at 115200 and it may just not be in sync with PC. You could try sending characters in PuTTY and see with a scope what baud rate they get sent from the ICDI to the target. The test points are near the reset button TXD and
  13. Make the variable scope wide enough to include the interrupt function. static global or global. Make it volatile. Make the interrupt handler a dummy function that passes the variables to another sub-function. This still requires that the int handler have visibility to the variables in question.
  14. Soldering iron to gently heat and remove best choice. Side cutters will also cut the resistors. Or cut trace (last choice). No side effects. They are there for msp launchpad compatibility. Puts i2c and spi on same boosterpack pin.
  15. It seems to be working here. I download the drivers and tried to attach but they are 9MB and over the file size limit. I split it in two parts with 7zip tried to upload the parts and get a file type not permitted error. Tried to change file extension and still get the same error. Keep trying back on the ti website http://www.ti.com/tool/stellaris_icdi_drivers Sorry.
  16. http://www.ti.com/lsds/ti/microcontroller/tiva_arm_cortex/c_series/tm4c_arm_cortex-m4/overview.page Tiva MCU overview page. Bluehash, your 43oh blog is not quite accurate. "The part LM4F230H5QR on the Launchpad is still the same, but now changed to TM4C1233GH6PM." The Stellaris LaunchPad has a LM4F120H5QR. The Tiva appears to have a TM4C123GH6PM which appears to be equal to the LM4F230H5QR. This is how Tiva adds motion PWM, QEI and USB host/OTG. Looks like the TI web folks are still tinkering with things, I'd suspect a more formal announcement is coming soon. Datasheets ar
  17. What you are asking doesn't sound like "standard" practice. Can you give us a bigger picture of why you want this behavior? Instead of us trying to help implement a single possible solution, if you first help us understand the bigger problem you want to solve chances are good that someone has seen this before and may have a different approach that you had not considered which is likely more elegant. If you really want to implement this particular solution, i'd suggest using a general purpose timer. Set it to interrupt on the threshold. Do not enable the timer to count automatically.
  18. What you want is a USB composite serial plus mass storage. Get a full copy of StellarisWare for all boards. http://www.ti.com/sw-lm3s The old EK-LM3S9D92 kit has a composite example that is a HID with serial. Find that example in C:\StellarisWare\boards\ek-lm3s9d92\usb_dev_chidcdc\ port it to the LM4F120. The port should be only to configure the USB Port D Pins as USB mode not GPIO during your init code. The rest should work. almost straight away. Once you have that working on the LM4F120 remove the HID stuff from the example and replace it with mass storage. Look for usb_dev_msc
  19. This was done for MSP430 compatibility on those pins. PB6 and 7 provide SSI functions. PD0 and PD1 provide I2C function. The MSP has a module that provides both on the same MCU pin. The Stellaris requires using two pins to match the MSP functionality. Dexter
  20. The I2C is available in the same place on the right hand header. Examine the schematic closely there is a zero ohm that ties some I2C pins over to the right hand outside header at the same place as the MSP430 LaunchPad. StellarisWare\docs\SW-DRL-UGxxxx.pdf is the API documentation for StellarisWare Driver Library. It is very helpful. it's designed to work across 5+ different IDE's/Compilers so it is much more independent of the compiler. Start with the examples in StellarisWare\boards\ek-lm4f120xl and build on them.
  21. UARTprintf does not yet support floats directly. A couple of options exist. 1) use sprintf or similar from the standard 'C' libraries to do the float to string conversion into a character array and then use %s with UARTprintf to put the float (which is now stored as a string in the array) on the UART. 2) Do a little bit of casting and multiplying. cast the float to a integer. Call this the integer part. multiply the float by something like 1000 to get three decimal points of precision. cast this new number to an integer again and now subtract off the integer part * 1000. Call
  22. The asserts are OFF by default in all StellarisWare projects that i know of. If they are on you would see DEBUG defined in the project settings or makefile as a "pre-defined' symbol. the GPIO functions in DriverLib take advantage of the bit masking feature of the GPIO ports (think atomic read modify write in hardware). However, the calculate the address offset on the fly so are not the fastest. For fastest operation you will want to access GPIO through the AHB interface not the default (per driverlib) APB. Dellwood
  23. The Wiki has a how-to document for debugging the board with an external JTAG adapter. The still working LaunchPad could be used as the JTAG adapter in this case. http://processors.wiki.ti.com/index.php/Stellaris_LM4F120_LaunchPad_Debug_How_To
  24. The Stellaris GPIOS connect to the core through both the APB and the AHB busses. The AHB is faster. Use SysCtlGPIOAHBEnable to enable the port you want. Then for absolute fastest toggle use HWREG(AHB BASE ADDRESS + (pin mask << 2)) = GPIO_PIN_x; // or zero. The pin mask is a feature of stellaris that allows you to add an offset to the base address which becomes a pin mask. You can then write a single pin of a GPIO port without doing a read modify write. The hardware only twiddles the pins that set in the mask value. The right shift by 2 makes each pin mask a unique 32 bit ad
  25. Also look at the examples for the earlier stellaris kits that have an SD card. EK-LM3S6965, EK-LM3S3748, EK-LM4F232 Examples in the StellarisWare\Boards\<board part number>\ directory of the full StellarisWare download http://www.ti.com/tool/sw-lm3s TI uses an older version of FATFs open source file system. I think they even have a example to be a USB Mass storage device using the SD Card. usb_dev_msc.
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