огшор
Dependencies: CMSIS_DSP_401 mbed
Fork of fir_f32 by
main.cpp@4:397e8f4699df, 2014-10-23 (annotated)
- Committer:
- Sergeev
- Date:
- Thu Oct 23 15:58:45 2014 +0000
- Revision:
- 4:397e8f4699df
- Parent:
- 3:1f56b8f439a1
- Child:
- 5:bd3887263120
- Child:
- 6:173ae8477ae1
Yes
Who changed what in which revision?
User | Revision | Line number | New contents of line |
---|---|---|---|
Sergeev | 0:b712470aea1d | 1 | #include "mbed.h" |
Sergeev | 1:9b1df0b2507d | 2 | #include <ctype.h> |
Sergeev | 0:b712470aea1d | 3 | #include "arm_math.h" |
Sergeev | 1:9b1df0b2507d | 4 | #include "arm_const_structs.h" |
Sergeev | 1:9b1df0b2507d | 5 | |
Sergeev | 1:9b1df0b2507d | 6 | void arm_cfft_f32( |
Sergeev | 1:9b1df0b2507d | 7 | const arm_cfft_instance_f32 * S, |
Sergeev | 1:9b1df0b2507d | 8 | float32_t * p1, |
Sergeev | 1:9b1df0b2507d | 9 | uint8_t ifftFlag, |
Sergeev | 1:9b1df0b2507d | 10 | uint8_t bitReverseFlag); |
Sergeev | 0:b712470aea1d | 11 | |
Sergeev | 1:9b1df0b2507d | 12 | Serial pc(USBTX, USBRX); |
Sergeev | 1:9b1df0b2507d | 13 | |
Sergeev | 1:9b1df0b2507d | 14 | AnalogIn left(A2); |
Sergeev | 1:9b1df0b2507d | 15 | AnalogIn right(A3); |
Sergeev | 1:9b1df0b2507d | 16 | |
Sergeev | 1:9b1df0b2507d | 17 | int SAMPLE_RATE_HZ = 40000; // Sample rate of the audio in hertz. |
Sergeev | 1:9b1df0b2507d | 18 | const int FFT_SIZE = 16; // Size of the FFT. |
Sergeev | 1:9b1df0b2507d | 19 | |
Sergeev | 1:9b1df0b2507d | 20 | const static arm_cfft_instance_f32 *S; |
Sergeev | 3:1f56b8f439a1 | 21 | //static arm_cfft_radix2_instance_f32 *S; |
Sergeev | 1:9b1df0b2507d | 22 | Ticker samplingTimer; |
Sergeev | 1:9b1df0b2507d | 23 | float samples[FFT_SIZE*2]; |
Sergeev | 1:9b1df0b2507d | 24 | float magnitudes[FFT_SIZE]; |
Sergeev | 1:9b1df0b2507d | 25 | int sampleCounter = 0; |
Sergeev | 1:9b1df0b2507d | 26 | |
Sergeev | 1:9b1df0b2507d | 27 | void samplingCallback() |
Sergeev | 3:1f56b8f439a1 | 28 | { |
Sergeev | 1:9b1df0b2507d | 29 | // Read from the ADC and store the sample data |
Sergeev | 3:1f56b8f439a1 | 30 | samples[sampleCounter] = 1000*left.read(); |
Sergeev | 1:9b1df0b2507d | 31 | // Complex FFT functions require a coefficient for the imaginary part of the input. |
Sergeev | 1:9b1df0b2507d | 32 | // Since we only have real data, set this coefficient to zero. |
Sergeev | 1:9b1df0b2507d | 33 | samples[sampleCounter+1] = 0.0; |
Sergeev | 1:9b1df0b2507d | 34 | // Update sample buffer position and stop after the buffer is filled |
Sergeev | 3:1f56b8f439a1 | 35 | |
Sergeev | 1:9b1df0b2507d | 36 | sampleCounter += 2; |
Sergeev | 2:707eb5bc5dfc | 37 | |
Sergeev | 1:9b1df0b2507d | 38 | if (sampleCounter >= FFT_SIZE*2) { |
Sergeev | 1:9b1df0b2507d | 39 | samplingTimer.detach(); |
Sergeev | 1:9b1df0b2507d | 40 | } |
Sergeev | 1:9b1df0b2507d | 41 | } |
Sergeev | 1:9b1df0b2507d | 42 | |
Sergeev | 1:9b1df0b2507d | 43 | void samplingBegin() |
Sergeev | 1:9b1df0b2507d | 44 | { |
Sergeev | 1:9b1df0b2507d | 45 | // Reset sample buffer position and start callback at necessary rate. |
Sergeev | 1:9b1df0b2507d | 46 | sampleCounter = 0; |
Sergeev | 3:1f56b8f439a1 | 47 | samplingTimer.attach_us(&samplingCallback, (float)(1000000/SAMPLE_RATE_HZ)); |
Sergeev | 1:9b1df0b2507d | 48 | } |
Sergeev | 1:9b1df0b2507d | 49 | |
Sergeev | 1:9b1df0b2507d | 50 | bool samplingIsDone() |
Sergeev | 1:9b1df0b2507d | 51 | { |
Sergeev | 1:9b1df0b2507d | 52 | return sampleCounter >= FFT_SIZE*2; |
Sergeev | 0:b712470aea1d | 53 | } |
Sergeev | 1:9b1df0b2507d | 54 | |
Sergeev | 1:9b1df0b2507d | 55 | int main() |
Sergeev | 0:b712470aea1d | 56 | { |
Sergeev | 1:9b1df0b2507d | 57 | // Set up serial port. |
Sergeev | 3:1f56b8f439a1 | 58 | //pc.baud (38400); |
Sergeev | 1:9b1df0b2507d | 59 | |
Sergeev | 1:9b1df0b2507d | 60 | // Init arm_ccft_32 |
Sergeev | 1:9b1df0b2507d | 61 | switch (FFT_SIZE) |
Sergeev | 1:9b1df0b2507d | 62 | { |
Sergeev | 1:9b1df0b2507d | 63 | case 16: |
Sergeev | 1:9b1df0b2507d | 64 | S = & arm_cfft_sR_f32_len16; |
Sergeev | 1:9b1df0b2507d | 65 | break; |
Sergeev | 1:9b1df0b2507d | 66 | case 32: |
Sergeev | 1:9b1df0b2507d | 67 | S = & arm_cfft_sR_f32_len32; |
Sergeev | 1:9b1df0b2507d | 68 | break; |
Sergeev | 1:9b1df0b2507d | 69 | case 64: |
Sergeev | 1:9b1df0b2507d | 70 | S = & arm_cfft_sR_f32_len64; |
Sergeev | 1:9b1df0b2507d | 71 | break; |
Sergeev | 1:9b1df0b2507d | 72 | case 128: |
Sergeev | 1:9b1df0b2507d | 73 | S = & arm_cfft_sR_f32_len128; |
Sergeev | 1:9b1df0b2507d | 74 | break; |
Sergeev | 1:9b1df0b2507d | 75 | case 256: |
Sergeev | 1:9b1df0b2507d | 76 | S = & arm_cfft_sR_f32_len256; |
Sergeev | 1:9b1df0b2507d | 77 | break; |
Sergeev | 1:9b1df0b2507d | 78 | case 512: |
Sergeev | 1:9b1df0b2507d | 79 | S = & arm_cfft_sR_f32_len512; |
Sergeev | 1:9b1df0b2507d | 80 | break; |
Sergeev | 1:9b1df0b2507d | 81 | case 1024: |
Sergeev | 1:9b1df0b2507d | 82 | S = & arm_cfft_sR_f32_len1024; |
Sergeev | 1:9b1df0b2507d | 83 | break; |
Sergeev | 1:9b1df0b2507d | 84 | case 2048: |
Sergeev | 1:9b1df0b2507d | 85 | S = & arm_cfft_sR_f32_len2048; |
Sergeev | 1:9b1df0b2507d | 86 | break; |
Sergeev | 1:9b1df0b2507d | 87 | case 4096: |
Sergeev | 1:9b1df0b2507d | 88 | S = & arm_cfft_sR_f32_len4096; |
Sergeev | 1:9b1df0b2507d | 89 | break; |
Sergeev | 1:9b1df0b2507d | 90 | } |
Sergeev | 1:9b1df0b2507d | 91 | float maxValue = 0.0f; |
Sergeev | 1:9b1df0b2507d | 92 | unsigned int testIndex = 0; |
Sergeev | 1:9b1df0b2507d | 93 | |
Sergeev | 1:9b1df0b2507d | 94 | // Begin sampling audio |
Sergeev | 1:9b1df0b2507d | 95 | samplingBegin(); |
Sergeev | 1:9b1df0b2507d | 96 | |
Sergeev | 1:9b1df0b2507d | 97 | while(1) |
Sergeev | 1:9b1df0b2507d | 98 | { |
Sergeev | 1:9b1df0b2507d | 99 | // Calculate FFT if a full sample is available. |
Sergeev | 1:9b1df0b2507d | 100 | if (samplingIsDone()) |
Sergeev | 3:1f56b8f439a1 | 101 | { |
Sergeev | 1:9b1df0b2507d | 102 | // Run FFT on sample data. |
Sergeev | 1:9b1df0b2507d | 103 | //arm_cfft_radix2_f32(arm_cfft_radix2_instance_f32*S, samples); |
Sergeev | 1:9b1df0b2507d | 104 | arm_cfft_f32(S, samples, 0, 1); |
Sergeev | 4:397e8f4699df | 105 | samples[0] = 0; |
Sergeev | 3:1f56b8f439a1 | 106 | /* Initialize the CFFT/CIFFT module */ |
Sergeev | 3:1f56b8f439a1 | 107 | //arm_cfft_radix2_init_f32(S, 128, 0, 1); |
Sergeev | 3:1f56b8f439a1 | 108 | //arm_cfft_radix2_f32(S, samples); |
Sergeev | 1:9b1df0b2507d | 109 | for(int i = 0;i < FFT_SIZE*2;++i) |
Sergeev | 3:1f56b8f439a1 | 110 | pc.printf(" Samples[%d]: %8.2f ",i,samples[i]); |
Sergeev | 2:707eb5bc5dfc | 111 | pc.printf("\r\n"); |
Sergeev | 1:9b1df0b2507d | 112 | // Calculate magnitude of complex numbers output by the FFT. |
Sergeev | 1:9b1df0b2507d | 113 | arm_cmplx_mag_f32(samples, magnitudes, FFT_SIZE); |
Sergeev | 1:9b1df0b2507d | 114 | for(int i = 0;i < FFT_SIZE;++i) |
Sergeev | 3:1f56b8f439a1 | 115 | pc.printf(" Magnitude: %d = %8.2f ;", i, magnitudes[i]); |
Sergeev | 3:1f56b8f439a1 | 116 | pc.printf(" \r\n"); |
Sergeev | 1:9b1df0b2507d | 117 | arm_max_f32(magnitudes, FFT_SIZE, &maxValue, &testIndex); |
Sergeev | 3:1f56b8f439a1 | 118 | pc.printf(" MAX value at magnitudes[%d] : %+8.2f\r\n", testIndex, maxValue); |
Sergeev | 1:9b1df0b2507d | 119 | // Wait for user confirmation to restart audio sampling. |
Sergeev | 1:9b1df0b2507d | 120 | //pc.getc(); |
Sergeev | 1:9b1df0b2507d | 121 | wait(1); |
Sergeev | 1:9b1df0b2507d | 122 | samplingBegin(); |
Sergeev | 1:9b1df0b2507d | 123 | } |
Sergeev | 1:9b1df0b2507d | 124 | } |
Sergeev | 0:b712470aea1d | 125 | } |