diff options
Diffstat (limited to 'Core/Src/main.c')
| -rw-r--r-- | Core/Src/main.c | 65 |
1 files changed, 53 insertions, 12 deletions
diff --git a/Core/Src/main.c b/Core/Src/main.c index aa520a3..6b7fad0 100644 --- a/Core/Src/main.c +++ b/Core/Src/main.c @@ -22,18 +22,23 @@ /* Private includes ----------------------------------------------------------*/
/* USER CODE BEGIN Includes */
#include <stdio.h>
+#include <qfplib-port.h>
/* USER CODE END Includes */
/* Private typedef -----------------------------------------------------------*/
/* USER CODE BEGIN PTD */
-typedef struct {
+typedef struct {
int32_t value : 18;
} sample_t;
/* USER CODE END PTD */
/* Private define ------------------------------------------------------------*/
/* USER CODE BEGIN PD */
-
+#define SAMPLE_COUNT (512) // Sample count per half-transfer
+#define MIC_OFFSET_DB ( 0.f) // Linear offset
+#define MIC_SENSITIVITY (-26.f) // dBFS value expected at MIC_REF_DB
+#define MIC_REF_DB ( 94.f) // dB where sensitivity is specified
+#define MIC_BITS (18)
/* USER CODE END PD */
/* Private macro -------------------------------------------------------------*/
@@ -50,10 +55,16 @@ DMA_HandleTypeDef hdma_spi1_tx; UART_HandleTypeDef huart2;
/* USER CODE BEGIN PV */
-static /*const*/ uint8_t I2S_Frame_Buffer[8] = {
+static const uint8_t I2S_Frame_Buffer[8] = {
0x00, 0x00, 0x00, 0x00, 0xFF, 0xFF, 0xFF, 0xFF
};
-static uint8_t I2S_Receive_Buffer[4096];
+static uint8_t I2S_Receive_Buffer[SAMPLE_COUNT * sizeof(sample_t)];
+
+float ln10;
+float MIC_REF_AMPL;
+
+static float DB_Sum_Squares = 0.f;
+static unsigned DB_Count = 0;
/* USER CODE END PV */
/* Private function prototypes -----------------------------------------------*/
@@ -65,7 +76,7 @@ static void MX_USART2_UART_Init(void); /* USER CODE BEGIN PFP */
static HAL_StatusTypeDef HAL_SPI_TransmitReceive_DMA_Mixed(
SPI_HandleTypeDef *hspi,
- uint8_t *pTxData,
+ const uint8_t *pTxData,
uint8_t *pRxData,
uint16_t TxSize,
uint16_t RxSize);
@@ -91,7 +102,9 @@ int main(void) {
/* USER CODE BEGIN 1 */
-
+ ln10 = qfp_fln(10.f);
+ MIC_REF_AMPL = qfp_fmul(qfp_int2float((1 << (MIC_BITS - 1)) - 1),
+ qfp_fpow(10.f, MIC_SENSITIVITY / 20.f));
/* USER CODE END 1 */
/* MCU Configuration--------------------------------------------------------*/
@@ -426,7 +439,7 @@ static void MX_GPIO_Init(void) /* USER CODE BEGIN 4 */
HAL_StatusTypeDef HAL_SPI_TransmitReceive_DMA_Mixed(
SPI_HandleTypeDef *hspi,
- uint8_t *pTxData,
+ const uint8_t *pTxData,
uint8_t *pRxData,
uint16_t TxSize,
uint16_t RxSize)
@@ -507,13 +520,44 @@ void SPI_DMATransmitReceiveCplt(DMA_HandleTypeDef *hdma) (void)hspi;
}
+static float process(float in_div4)
+{
+ static float z1 = 0, z2 = 0, z3 = 0, z5 = 0;
+
+ float out1 = qfp_fadd(in_div4, z1);
+ z1 = qfp_fadd(qfp_fmul(1.062f, out1), z2);
+ z2 = qfp_fsub(qfp_fmul(-0.14f, out1), in_div4);
+
+ float out2 = qfp_fadd(out1, z3);
+ z3 = out1;
+
+ float out3 = qfp_fadd(out2, z5);
+ z5 = qfp_fsub(qfp_fmul(0.985f, out3), out2);
+
+ return out3;
+}
+
void SPI_DMAHalfTransmitReceiveCplt(DMA_HandleTypeDef *hdma)
{
SPI_HandleTypeDef *hspi = (SPI_HandleTypeDef *)hdma->Parent;
(void)hspi;
- sample_t sample = *(sample_t *)I2S_Receive_Buffer;
- printf("%d\r\n", sample.value);
+ sample_t *sample = (sample_t *)I2S_Receive_Buffer;
+ for (int i = 0; i < SAMPLE_COUNT / 8; i++) {
+ float f = process(qfp_int2float(sample[i].value / 4));
+ DB_Sum_Squares = qfp_fadd(DB_Sum_Squares, qfp_fmul(f, f));
+ }
+ DB_Count += SAMPLE_COUNT / 8;
+
+ if (DB_Count > 48000 / 4) {
+ float rms = qfp_fsqrt(qfp_fdiv(DB_Sum_Squares, qfp_uint2float(DB_Count)));
+ float db = qfp_fadd(MIC_OFFSET_DB + MIC_REF_DB, qfp_fmul(20.f,
+ qfp_flog10(qfp_fdiv(rms, MIC_REF_AMPL))));
+ DB_Sum_Squares = 0.f;
+ DB_Count = 0;
+
+ printf("%d\r\n", qfp_float2int(db));
+ }
}
/* USER CODE END 4 */
@@ -524,7 +568,6 @@ void SPI_DMAHalfTransmitReceiveCplt(DMA_HandleTypeDef *hdma) void Error_Handler(void)
{
/* USER CODE BEGIN Error_Handler_Debug */
- /* User can add his own implementation to report the HAL error return state */
__disable_irq();
printf("Unhandled error, halting!\r\n");
while (1)
@@ -544,8 +587,6 @@ void Error_Handler(void) void assert_failed(uint8_t *file, uint32_t line)
{
/* USER CODE BEGIN 6 */
- /* User can add his own implementation to report the file name and line number,
- ex: printf("Wrong parameters value: file %s on line %d\r\n", file, line) */
printf("Wrong parameters value: file %s on line %d\r\n", file, line);
/* USER CODE END 6 */
}
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