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M-Three

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  1. I have the LM3s9b92 evaluation kit and get the following error when I try debug it. Anyone know what is going on? CORTEX_M3_0: Flash Programmer: Timed out while writing to Flash memory CORTEX_M3_0: Trouble Writing Memory Block at
  2. Jeez.. that's a neat little project. Lucky for him to get his hands on a Stellaris LP.
  3. Hackaday post. Flurry of activity. Looks like everyone has been waiting for this.
  4. Estore Link. Max limit of two. Spread the word.
  5. Yes.. I like all this competition.. good for us. Also, I hear that their StellarisWare is pretty decent.
  6. Here is a link with those two stellaris launchpad boosterpacks in the list.
  7. The board has micro-SD card, USB host, USB-OTG,all ports break out on connectors and ARDUINO platform connectors. MAPLE support for F4 is on the way, so this board will be one powerful Arduino alternative
  8. Was searching for FFT libraries when I came across this player. Reads files from an SD card using FatFS by ChaN, displays a spectrum graph on an LCD using the FFT dsp library from Ivan Mellen. Mini-STM32 WAVE Audio Player.7z
  9. I was looking around for a general dsp library to do FFTs when I came across this page. Has a sh*t ton of stuff, hopefully helpful to you guys. Four groups of functions: Windowing function Fast Fourier Transform Complex magnitude (absolute value of complex frequency) Miscellaneous functions: logarithm(x), exp(x), pseudorandom generator Three library versions GCC ( Rowley CrossWorks, Raisonance, …) Keil MDK-ARM IAR Embedded Workbench Windowing functions (e.g. Hamming window) Windowing is very common step before FFT calculation Perform speed optimized windowing of input signal before FFT 16 to 32 bit version performs proper scaling of 16 bit signal for 32 bit FFT FFT functions Complex and real FFT, 16 and 32bit FFT versions Radix4/2 FFT – sizes 4,8,16,32,64,128,256,512,1024,2048 and 4096 Inverse FFT available Real FFT enables much more efficient processing of the real signals 16 bit FFT precision comparable with other fixed point implementation – precision determined by necessary scaling by 0.5 in every FFT stage 32 bit FFT increases dynamic range by 90 dB , needs extra 20% to 50% cycles Coefficients located in Flash. RAM location means faster FFT for higher latencies. Magnitude functions Calculate complex frequency magnitude mag=sqrt (re^2 + im^2) Based on custom 32 bit square root algorithm (7/13 cycles) Multiple versions of different speed / precision tradeoffs for 64 bit sqrt Logarithm and exponent functions Calculate log2(x) and exp2(x) = 2^x log2 input, exp2 output: 16q16 unsigned 1/65536 to 65535+65535/65536 log2 output, exp2 input : 5q27 signed -15.99999 to 15.99999 speed: 11/10 cycles ; precision 0.4 ppm / 3 ppm for log2 / exp2 single multiply conversion to log10(x), ln(x), 10^x, e^x and generic base log, exp Parallel MLS pseudorandom generator for ARM cpu Maximum Length Sequence generated by Linear Feedback Shift Registers Periode 2^31-1 to 2^64-1 words (1 to 64 bits wide) 1 to 64 bits generated in parallel Order of magnitude faster than bit based approach, 3-10 cycles per whole word
  10. Choose as many as you work on.
  11. Thanks! Registered and submitted. Does it say "uk only" anywhere? I can't see it on the page.
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