15b4baba28
- minimize RAM usage of all components - use both IRAM and DRAM in player component so we can buffer up to 1s on modules without SPI RAM - support fragemented pcm chunks so we can use all available RAM if there isn't a big enough block available but still enough HEAP - reinclude all components from jorgen's master branch - add custom i2s driver to get a precise timing of initial sync - change wrong usage of esp_timer for latency measurement of snapcast protocol - add player component
102 lines
3.1 KiB
C
102 lines
3.1 KiB
C
// Copyright 2018-2019 Espressif Systems (Shanghai) PTE LTD
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include "freertos/FreeRTOS.h"
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#include "freertos/task.h"
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#include "esp_system.h"
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#include "driver/spi_master.h"
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#include "soc/gpio_struct.h"
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#include "driver/gpio.h"
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#include "driver/uart.h"
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#include "soc/uart_struct.h"
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#include <math.h>
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#include "esp_dsp.h"
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static const char *TAG = "main";
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// This example shows how to use FFT from esp-dsp library
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#define N_SAMPLES 1024
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int N = N_SAMPLES;
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// Input test array
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float x1[N_SAMPLES];
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float x2[N_SAMPLES];
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// Window coefficients
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float wind[N_SAMPLES];
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// working complex array
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float y_cf[N_SAMPLES*2];
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// Pointers to result arrays
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float* y1_cf = &y_cf[0];
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float* y2_cf = &y_cf[N_SAMPLES];
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// Sum of y1 and y2
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float sum_y[N_SAMPLES/2];
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void app_main()
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{
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esp_err_t ret;
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ESP_LOGI(TAG, "Start Example.");
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ret = dsps_fft2r_init_fc32(NULL, CONFIG_DSP_MAX_FFT_SIZE);
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if (ret != ESP_OK)
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{
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ESP_LOGE(TAG, "Not possible to initialize FFT. Error = %i", ret);
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return;
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}
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// Generate hann window
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dsps_wind_hann_f32(wind, N);
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// Generate input signal for x1 A=1 , F=0.1
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dsps_tone_gen_f32(x1, N, 1.0, 0.16, 0);
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// Generate input signal for x2 A=0.1,F=0.2
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dsps_tone_gen_f32(x2, N, 0.1, 0.2, 0);
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// Convert two input vectors to one complex vector
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for (int i=0 ; i< N ; i++)
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{
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y_cf[i*2 + 0] = x1[i] * wind[i];
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y_cf[i*2 + 1] = x2[i] * wind[i];
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}
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// FFT
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unsigned int start_b = xthal_get_ccount();
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dsps_fft2r_fc32(y_cf, N);
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unsigned int end_b = xthal_get_ccount();
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// Bit reverse
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dsps_bit_rev_fc32(y_cf, N);
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// Convert one complex vector to two complex vectors
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dsps_cplx2reC_fc32(y_cf, N);
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for (int i = 0 ; i < N/2 ; i++) {
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y1_cf[i] = 10 * log10f((y1_cf[i * 2 + 0] * y1_cf[i * 2 + 0] + y1_cf[i * 2 + 1] * y1_cf[i * 2 + 1])/N);
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y2_cf[i] = 10 * log10f((y2_cf[i * 2 + 0] * y2_cf[i * 2 + 0] + y2_cf[i * 2 + 1] * y2_cf[i * 2 + 1])/N);
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// Simple way to show two power spectrums as one plot
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sum_y[i] = fmax(y1_cf[i], y2_cf[i]);
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}
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// Show power spectrum in 64x10 window from -100 to 0 dB from 0..N/4 samples
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ESP_LOGW(TAG, "Signal x1");
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dsps_view(y1_cf, N/2, 64, 10, -60, 40, '|');
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ESP_LOGW(TAG, "Signal x2");
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dsps_view(y2_cf, N/2, 64, 10, -60, 40, '|');
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ESP_LOGW(TAG, "Signals x1 and x2 on one plot");
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dsps_view(sum_y, N/2, 64, 10, -60, 40, '|');
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ESP_LOGI(TAG, "FFT for %i complex points take %i cycles", N, end_b - start_b);
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ESP_LOGI(TAG, "End Example.");
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}
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