From 6ab94e0b318884bbcb95e2ea3835f951502e1d99 Mon Sep 17 00:00:00 2001 From: jaseg Date: Wed, 14 Oct 2020 12:47:28 +0200 Subject: Move firmware into subdirectory --- .../ARM/arm_fir_example/arm_fir_example_f32.c | 233 +++++++++++++++++++++ 1 file changed, 233 insertions(+) create mode 100644 fw/cdc-dials/Drivers/CMSIS/DSP/Examples/ARM/arm_fir_example/arm_fir_example_f32.c (limited to 'fw/cdc-dials/Drivers/CMSIS/DSP/Examples/ARM/arm_fir_example/arm_fir_example_f32.c') diff --git a/fw/cdc-dials/Drivers/CMSIS/DSP/Examples/ARM/arm_fir_example/arm_fir_example_f32.c b/fw/cdc-dials/Drivers/CMSIS/DSP/Examples/ARM/arm_fir_example/arm_fir_example_f32.c new file mode 100644 index 0000000..3dd9f5a --- /dev/null +++ b/fw/cdc-dials/Drivers/CMSIS/DSP/Examples/ARM/arm_fir_example/arm_fir_example_f32.c @@ -0,0 +1,233 @@ +/* ---------------------------------------------------------------------- + * Copyright (C) 2010-2012 ARM Limited. All rights reserved. + * +* $Date: 17. January 2013 +* $Revision: V1.4.0 +* +* Project: CMSIS DSP Library + * Title: arm_fir_example_f32.c + * + * Description: Example code demonstrating how an FIR filter can be used + * as a low pass filter. + * + * Target Processor: Cortex-M4/Cortex-M3 + * +* Redistribution and use in source and binary forms, with or without +* modification, are permitted provided that the following conditions +* are met: +* - Redistributions of source code must retain the above copyright +* notice, this list of conditions and the following disclaimer. +* - Redistributions in binary form must reproduce the above copyright +* notice, this list of conditions and the following disclaimer in +* the documentation and/or other materials provided with the +* distribution. +* - Neither the name of ARM LIMITED nor the names of its contributors +* may be used to endorse or promote products derived from this +* software without specific prior written permission. +* +* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS +* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT +* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS +* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE +* COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, +* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, +* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; +* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER +* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT +* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN +* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE +* POSSIBILITY OF SUCH DAMAGE. + * -------------------------------------------------------------------- */ + +/** + * @ingroup groupExamples + */ + +/** + * @defgroup FIRLPF FIR Lowpass Filter Example + * + * \par Description: + * \par + * Removes high frequency signal components from the input using an FIR lowpass filter. + * The example demonstrates how to configure an FIR filter and then pass data through + * it in a block-by-block fashion. + * \image html FIRLPF_signalflow.gif + * + * \par Algorithm: + * \par + * The input signal is a sum of two sine waves: 1 kHz and 15 kHz. + * This is processed by an FIR lowpass filter with cutoff frequency 6 kHz. + * The lowpass filter eliminates the 15 kHz signal leaving only the 1 kHz sine wave at the output. + * \par + * The lowpass filter was designed using MATLAB with a sample rate of 48 kHz and + * a length of 29 points. + * The MATLAB code to generate the filter coefficients is shown below: + * 
+ *     h = fir1(28, 6/24);
+ *
+ * The first argument is the "order" of the filter and is always one less than the desired length. + * The second argument is the normalized cutoff frequency. This is in the range 0 (DC) to 1.0 (Nyquist). + * A 6 kHz cutoff with a Nyquist frequency of 24 kHz lies at a normalized frequency of 6/24 = 0.25. + * The CMSIS FIR filter function requires the coefficients to be in time reversed order. + * 
+ *     fliplr(h)
+ *
+ * The resulting filter coefficients and are shown below. + * Note that the filter is symmetric (a property of linear phase FIR filters) + * and the point of symmetry is sample 14. Thus the filter will have a delay of + * 14 samples for all frequencies. + * \par + * \image html FIRLPF_coeffs.gif + * \par + * The frequency response of the filter is shown next. + * The passband gain of the filter is 1.0 and it reaches 0.5 at the cutoff frequency 6 kHz. + * \par + * \image html FIRLPF_response.gif + * \par + * The input signal is shown below. + * The left hand side shows the signal in the time domain while the right hand side is a frequency domain representation. + * The two sine wave components can be clearly seen. + * \par + * \image html FIRLPF_input.gif + * \par + * The output of the filter is shown below. The 15 kHz component has been eliminated. + * \par + * \image html FIRLPF_output.gif + * + * \par Variables Description: + * \par + * \li \c testInput_f32_1kHz_15kHz points to the input data + * \li \c refOutput points to the reference output data + * \li \c testOutput points to the test output data + * \li \c firStateF32 points to state buffer + * \li \c firCoeffs32 points to coefficient buffer + * \li \c blockSize number of samples processed at a time + * \li \c numBlocks number of frames + * + * \par CMSIS DSP Software Library Functions Used: + * \par + * - arm_fir_init_f32() + * - arm_fir_f32() + * + * Refer + * \link arm_fir_example_f32.c \endlink + * + */ + + +/** \example arm_fir_example_f32.c + */ + +/* ---------------------------------------------------------------------- +** Include Files +** ------------------------------------------------------------------- */ + +#include "arm_math.h" +#include "math_helper.h" + +/* ---------------------------------------------------------------------- +** Macro Defines +** ------------------------------------------------------------------- */ + +#define TEST_LENGTH_SAMPLES 320 +#define SNR_THRESHOLD_F32 140.0f +#define BLOCK_SIZE 32 +#define NUM_TAPS 29 + +/* ------------------------------------------------------------------- + * The input signal and reference output (computed with MATLAB) + * are defined externally in arm_fir_lpf_data.c. + * ------------------------------------------------------------------- */ + +extern float32_t testInput_f32_1kHz_15kHz[TEST_LENGTH_SAMPLES]; +extern float32_t refOutput[TEST_LENGTH_SAMPLES]; + +/* ------------------------------------------------------------------- + * Declare Test output buffer + * ------------------------------------------------------------------- */ + +static float32_t testOutput[TEST_LENGTH_SAMPLES]; + +/* ------------------------------------------------------------------- + * Declare State buffer of size (numTaps + blockSize - 1) + * ------------------------------------------------------------------- */ + +static float32_t firStateF32[BLOCK_SIZE + NUM_TAPS - 1]; + +/* ---------------------------------------------------------------------- +** FIR Coefficients buffer generated using fir1() MATLAB function. +** fir1(28, 6/24) +** ------------------------------------------------------------------- */ + +const float32_t firCoeffs32[NUM_TAPS] = { + -0.0018225230f, -0.0015879294f, +0.0000000000f, +0.0036977508f, +0.0080754303f, +0.0085302217f, -0.0000000000f, -0.0173976984f, + -0.0341458607f, -0.0333591565f, +0.0000000000f, +0.0676308395f, +0.1522061835f, +0.2229246956f, +0.2504960933f, +0.2229246956f, + +0.1522061835f, +0.0676308395f, +0.0000000000f, -0.0333591565f, -0.0341458607f, -0.0173976984f, -0.0000000000f, +0.0085302217f, + +0.0080754303f, +0.0036977508f, +0.0000000000f, -0.0015879294f, -0.0018225230f +}; + +/* ------------------------------------------------------------------ + * Global variables for FIR LPF Example + * ------------------------------------------------------------------- */ + +uint32_t blockSize = BLOCK_SIZE; +uint32_t numBlocks = TEST_LENGTH_SAMPLES/BLOCK_SIZE; + +float32_t snr; + +/* ---------------------------------------------------------------------- + * FIR LPF Example + * ------------------------------------------------------------------- */ + +int32_t main(void) +{ + uint32_t i; + arm_fir_instance_f32 S; + arm_status status; + float32_t *inputF32, *outputF32; + + /* Initialize input and output buffer pointers */ + inputF32 = &testInput_f32_1kHz_15kHz[0]; + outputF32 = &testOutput[0]; + + /* Call FIR init function to initialize the instance structure. */ + arm_fir_init_f32(&S, NUM_TAPS, (float32_t *)&firCoeffs32[0], &firStateF32[0], blockSize); + + /* ---------------------------------------------------------------------- + ** Call the FIR process function for every blockSize samples + ** ------------------------------------------------------------------- */ + + for(i=0; i < numBlocks; i++) + { + arm_fir_f32(&S, inputF32 + (i * blockSize), outputF32 + (i * blockSize), blockSize); + } + + /* ---------------------------------------------------------------------- + ** Compare the generated output against the reference output computed + ** in MATLAB. + ** ------------------------------------------------------------------- */ + + snr = arm_snr_f32(&refOutput[0], &testOutput[0], TEST_LENGTH_SAMPLES); + + if (snr < SNR_THRESHOLD_F32) + { + status = ARM_MATH_TEST_FAILURE; + } + else + { + status = ARM_MATH_SUCCESS; + } + + /* ---------------------------------------------------------------------- + ** Loop here if the signal does not match the reference output. + ** ------------------------------------------------------------------- */ + + if ( status != ARM_MATH_SUCCESS) + { + while (1); + } + + while (1); /* main function does not return */ +} + +/** \endlink */ -- cgit