Tomona Nanase
DISCO-F746NGのAudioOutから正弦波をスイープとして出力します。ダブルバッファリングを使って、リアルタイムにデータ生成をしています。 This program outputs sine sweep from AudioOut on DISCO-F746NG. The program uses double buffering when generates data signals.
Dependencies: BSP_DISCO_F746NG_patch_fixed LCD_DISCO_F746NG mbed
Diff: main.cpp
- Revision:
- 0:ece4ec581d2b
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/main.cpp Sat Dec 26 07:20:53 2015 +0000
@@ -0,0 +1,64 @@
+#include "main.h"
+
+LCD_DISCO_F746NG lcd;
+int16_t sweep_buffer[BufferSize];
+double sweep_phase = 0.0;
+double sweep_freq = MinFreq;
+
+void init_audio()
+{
+ if (BSP_AUDIO_OUT_Init(OUTPUT_DEVICE_BOTH, AudioVolume, SamplingFreq) == AUDIO_ERROR)
+ error_trap();
+
+ NVIC_SetVector(AUDIO_OUT_SAIx_DMAx_IRQ, (uint32_t)&AUDIO_OUT_SAIx_DMAx_IRQHandler);
+ BSP_AUDIO_OUT_SetAudioFrameSlot(CODEC_AUDIOFRAME_SLOT_02);
+}
+
+void play_audio()
+{
+ if (BSP_AUDIO_OUT_Play((uint16_t*)&sweep_buffer, BufferByteSize) == AUDIO_ERROR)
+ error_trap();
+}
+
+void fill_buffer(uint32_t offset, uint32_t size)
+{
+ static double sweep_freq_delta = 1.0 + SweepSpeed;
+ double sweep_phase_delta = 1.0 / SamplingFreq;
+ double new_freq;
+
+ for (int i = 0, j = offset; i < size / 2; i++ ) {
+ int16_t value = (int16_t)(Amplifier * sin(2.0 * PI * sweep_freq * sweep_phase) * 32767.5);
+ sweep_buffer[j++] = value;
+ sweep_buffer[j++] = value;
+
+ sweep_phase += sweep_phase_delta;
+ }
+
+ new_freq = sweep_freq * sweep_freq_delta;
+ sweep_phase = sweep_phase * sweep_freq / new_freq;
+ sweep_freq = new_freq;
+
+ if (sweep_freq > MaxFreq)
+ sweep_freq_delta = 1.0 - SweepSpeed;
+ else if (sweep_freq < MinFreq)
+ sweep_freq_delta = 1.0 + SweepSpeed;
+}
+
+int main()
+{
+ char strbuf[64];
+
+ lcd.Clear(LCD_COLOR_BLACK);
+ lcd.SetBackColor(LCD_COLOR_BLACK);
+ lcd.SetTextColor(LCD_COLOR_WHITE);
+ lcd.SetFont(&Font12);
+
+ init_audio();
+ play_audio();
+
+ while(1) {
+ sprintf(strbuf, "Freq: %.2f Hz, Phase: %.2f ", sweep_freq, sweep_phase);
+ printlcdAt(strbuf, 0);
+ wait_ms(100);
+ }
+}
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