update ring mod

4 files changed, 44 insertions, 25 deletions

diff --git a/Core/Inc/Effects/ringmod.h b/Core/Inc/Effects/ringmod.h
index 42cb229..516ca6c 100755
--- a/Core/Inc/Effects/ringmod.h
+++ b/Core/Inc/Effects/ringmod.h
@@ -10,7 +10,16 @@
 

 #include <stdint.h>

 #include <stddef.h>

+#include <stdbool.h>

 

-void ringmod(float *samples, size_t range_min, size_t range_max);

+typedef struct RingModParams {

+    float mix;

+    float frequency;

+    float lfo_amount;

+    float lfo_rate;

+    bool square_lfo;

+} RingModParams;

+

+void ringmod(float *samples, const size_t range_min, const size_t range_max, const struct RingModParams *params);

 

 #endif /* INC_EFFECTS_RINGMOD_H_ */

diff --git a/Core/Src/Effects/ringmod.c b/Core/Src/Effects/ringmod.c
index 732f68e..1b411dc 100755
--- a/Core/Src/Effects/ringmod.c
+++ b/Core/Src/Effects/ringmod.c
@@ -8,30 +8,34 @@
 #include "cs4272.h"

 #include "ringmod.h"

 #include <math.h>

+#include <float.h>

 

-/* ring modulator */

-void ringmod(float *samples, size_t range_min, size_t range_max) {

+/* MF-102S ring modulator */

+void ringmod(float *samples, const size_t range_min, const size_t range_max, const struct RingModParams *params) {

     static float lfo_phase = 0.0f;

     static float carrier_phase = 0.0f;

 

-    const float frequency = 156.0f;

-    const float amount = 0.67f;

     const float sample_rate = (float)SAMPLE_RATE;

+    const float inverse_sample_rate = 1.0f / sample_rate;

 

-    float lfo_increment = M_TWOPI * (0.18f / sample_rate);

-

-    /* plus two because of */

+    /* samples are interleaved */

     for (size_t i = range_min; i < range_max; i += 2) {

-        lfo_phase = fmodf(lfo_phase + lfo_increment, M_TWOPI);

+        float frequency_lfo = 0.0f;

 

-        float lfo = sinf(lfo_phase);

+        if (params->square_lfo) {

+            frequency_lfo = (lfo_phase < 0.5f) ? params->lfo_amount : -params->lfo_amount;

+        } else {

+            frequency_lfo = params->lfo_amount * sinf(M_TWOPI * lfo_phase);

+        }

 

-        float carrier_increment = M_TWOPI * ((frequency + lfo * (frequency * 3.0f * amount)) / sample_rate);

+        float carrier = sinf(M_TWOPI * carrier_phase);

 

-        carrier_phase = fmodf(carrier_phase + carrier_increment, M_TWOPI);

+        samples[i] = (samples[i] * (1.0f - params->mix)) + (samples[i] * carrier * params->mix);

 

-        float carrier = sinf(carrier_phase);

+        lfo_phase += params->lfo_rate * inverse_sample_rate;

+        lfo_phase = fmod(lfo_phase, 1.0f);

 

-        samples[i] = (samples[i] * 0.50f) + (samples[i] * carrier * 0.50f);

+        carrier_phase += (params->frequency + frequency_lfo) * inverse_sample_rate;

+        carrier_phase = fmod(carrier_phase, 1.0f);

     }

 }

diff --git a/Core/Src/cs4272.c b/Core/Src/cs4272.c
index 81179c7..9a7f0d1 100755
--- a/Core/Src/cs4272.c
+++ b/Core/Src/cs4272.c
@@ -9,6 +9,14 @@
 #include "cs4272.h"

 #include "ringmod.h"

 

+const struct RingModParams params = {

+    0.40f,

+    156.0f,

+    6.90f,

+    0.18f,

+    true,

+};

+

 volatile int32_t rx_buffer[BUFFER_SIZE] __attribute__((section(".audio_buffers")));

 volatile int32_t tx_buffer[BUFFER_SIZE] __attribute__((section(".audio_buffers")));

 volatile float samples[BUFFER_SIZE] __attribute__((section(".sdram")));

@@ -50,13 +58,13 @@ const uint8_t CS4272_CONFIG[7] = {
         0b00000010,

 };

 

-void int32_t_to_float(int32_t *in, float *out, size_t range_min, size_t range_max) {

+inline void int32_t_to_float(int32_t *in, float *out, const size_t range_min, const size_t range_max) {

     for (size_t i = range_min; i < range_max; ++i) {

         out[i] = ((float)(in[i] << 8)) / ((float)INT32_MAX);

     }

 }

 

-void float_to_int32_t(float *in, int32_t *out, size_t range_min, size_t range_max) {

+inline void float_to_int32_t(float *in, int32_t *out, const size_t range_min, const size_t range_max) {

     for (size_t i = range_min; i < range_max; ++i) {

         out[i] = ((int32_t)(in[i] * ((float)INT32_MAX))) >> 8;

     }

@@ -65,7 +73,7 @@ void float_to_int32_t(float *in, int32_t *out, size_t range_min, size_t range_ma
 void HAL_SAI_RxHalfCpltCallback(SAI_HandleTypeDef *hsai) {

     int32_t_to_float((int32_t *)rx_buffer, (float *)samples, 0, BUFFER_SIZE / 2);

 

-    ringmod((float *)samples, 0, BUFFER_SIZE / 2);

+    ringmod((float *)samples, 0, BUFFER_SIZE / 2, &params);

 

     float_to_int32_t((float *)samples, (int32_t *)tx_buffer, 0, BUFFER_SIZE / 2);

 }

@@ -73,20 +81,18 @@ void HAL_SAI_RxHalfCpltCallback(SAI_HandleTypeDef *hsai) {
 void HAL_SAI_RxCpltCallback(SAI_HandleTypeDef *hsai) {

     int32_t_to_float((int32_t *)rx_buffer, (float *)samples, BUFFER_SIZE / 2, BUFFER_SIZE);

 

-    ringmod((float *)samples, BUFFER_SIZE / 2, BUFFER_SIZE);

+    ringmod((float *)samples, BUFFER_SIZE / 2, BUFFER_SIZE, &params);

 

     float_to_int32_t((float *)samples, (int32_t *)tx_buffer, BUFFER_SIZE / 2, BUFFER_SIZE);

 }

 

 

-HAL_StatusTypeDef CS4272_ReadRegister(uint8_t addr, uint8_t *data) {

-    return HAL_I2C_Mem_Read(&hi2c4, CS4272_I2C_ADDR, addr, I2C_MEMADD_SIZE_8BIT,

-            data, 1, HAL_MAX_DELAY);

+HAL_StatusTypeDef CS4272_ReadRegister(const uint8_t addr, uint8_t *data) {

+    return HAL_I2C_Mem_Read(&hi2c4, CS4272_I2C_ADDR, addr, I2C_MEMADD_SIZE_8BIT, data, 1, HAL_MAX_DELAY);

 }

 

-HAL_StatusTypeDef CS4272_WriteRegister(uint8_t addr, uint8_t data) {

-    return HAL_I2C_Mem_Write(&hi2c4, CS4272_I2C_ADDR, addr,

-    I2C_MEMADD_SIZE_8BIT, &data, 1, HAL_MAX_DELAY);

+HAL_StatusTypeDef CS4272_WriteRegister(const uint8_t addr, uint8_t data) {

+    return HAL_I2C_Mem_Write(&hi2c4, CS4272_I2C_ADDR, addr, I2C_MEMADD_SIZE_8BIT, &data, 1, HAL_MAX_DELAY);

 }

 

 void CS4272_Reset(void) {

diff --git a/Core/Src/main.c b/Core/Src/main.c
index 9c58861..f7fdeac 100755
--- a/Core/Src/main.c
+++ b/Core/Src/main.c
@@ -121,7 +121,7 @@ int main(void)
   /* USER CODE BEGIN 2 */

 

   FMC_Init();

-  SDRAM_Test();

+  //SDRAM_Test();

 

   __HAL_RCC_SAI1_CLK_ENABLE();

   __HAL_SAI_ENABLE(&hsai_BlockA1);