diff --git a/Core/Inc/tlv320aic3104_ctrl.h b/Core/Inc/tlv320aic3104_ctrl.h
new file mode 100644
index 0000000..e75c1d5
--- /dev/null
+++ b/Core/Inc/tlv320aic3104_ctrl.h
@@ -0,0 +1,22 @@
+#ifndef __TLV320AIC3104_CTRL_H__
+#define __TLV320AIC3104_CTRL_H__
+
+#include <stdint.h>
+
+
+typedef enum CODEC_SELECT_en {
+   CODEC_A = 0,
+   CODEC_B = 1,
+} CODEC_SELECT;
+
+typedef enum TLV_PAGE_SELECT_en {
+   TLV_PAGE_0 = 0,
+   TLV_PAGE_1 = 1,
+} TLV_PAGE_SELECT;
+
+extern int16_t TlvPageSelect(CODEC_SELECT codec, TLV_PAGE_SELECT page);
+extern int16_t TlvReadReg(CODEC_SELECT codec, TLV_PAGE_SELECT page, uint8_t reg);
+extern int16_t TlvWriteReg(CODEC_SELECT codec, TLV_PAGE_SELECT page, uint8_t reg, uint8_t val);
+
+
+#endif
diff --git a/Core/Src/tlv320aic3104_ctrl.c b/Core/Src/tlv320aic3104_ctrl.c
new file mode 100644
index 0000000..fa7ba36
--- /dev/null
+++ b/Core/Src/tlv320aic3104_ctrl.c
@@ -0,0 +1,90 @@
+/***************************************************************************//**
+* @file  tlv320aic3104_ctrl.c
+* @brief Control functions for TLV320AIC3104 audio codec using I2C
+*//****************************************************************************/
+
+//------------------------------C library---------------------------------------
+#include <stdint.h>
+//----------------------------user includes-------------------------------------
+#include "tlv320aic3104_ctrl.h"
+#include "i2c_master.h"
+#include "main.h"
+//------------------------------------------------------------------------------
+
+
+/* Private macros ------------------------------------------------------------*/
+
+// Codecs on different I2C buses
+#define I2C_CODEC_A     I2C1
+#define I2C_CODEC_B     I2C3
+
+#define CODEC_I2C_ADDR  0x30     // left-aligned 7-bit slave address
+
+/* Private variables ---------------------------------------------------------*/
+static uint8_t PageSelect[2] = {0xFF, 0xFF}; // current page selected for each codec, to optimize page switching
+
+/* Functions -----------------------------------------------------------------*/
+
+
+/***************************************************************************//**
+* @brief  Read register value from codec
+* @param  codec: codec select (0 for CODEC_A, 1 for CODEC_B)
+* @param  page: page select (0 or 1)
+* @param  reg: register address (0-127)
+* @return register value (0-255) on success, negative error code on failure
+*//****************************************************************************/
+int16_t TlvReadReg(CODEC_SELECT codec, TLV_PAGE_SELECT page, uint8_t reg) {
+   if (page != PageSelect[codec]) {
+      int err = TlvPageSelect(codec, page);
+      if (err < 0) return err;
+   }
+   if (reg) reg--; // workaround: reading gives regaddr+1 positions back at (datasheet is wrong...)
+   uint8_t val = 0;
+   int err = I2C_ReadReg((codec == CODEC_A) ? I2C_CODEC_A : I2C_CODEC_B,
+                         CODEC_I2C_ADDR,
+                         &reg, 1,
+                         &val, 1);
+   if (err < 0) return err;
+   return val;
+}
+
+/***************************************************************************//**
+* @brief  Write register value to codec
+* @param  codec: codec select (0 for CODEC_A, 1 for CODEC_B)
+* @param  reg: register address (0-127)
+* @param  val: register value to write (0-255)
+* @return 0 on success, negative error code on failure
+*//****************************************************************************/
+int16_t TlvWriteReg(CODEC_SELECT codec, TLV_PAGE_SELECT page, uint8_t reg, uint8_t val) {
+   if (page != PageSelect[codec]) {
+      int err = TlvPageSelect(codec, page);
+      if (err < 0) return err;
+   }
+   uint8_t data[2] = {reg, val};
+   int err = I2C_Write((codec == CODEC_A) ? I2C_CODEC_A : I2C_CODEC_B,
+                         CODEC_I2C_ADDR,
+                         data, 2);
+   return err;
+}
+
+/***************************************************************************//**
+* @brief  Write register value to codec
+* @param  codec: codec select (0 for CODEC_A, 1 for CODEC_B)
+* @param  reg: register address (0-127)
+* @param  val: register value to write (0-255)
+* @return 0 on success, negative error code on failure
+*//****************************************************************************/
+int16_t TlvPageSelect(CODEC_SELECT codec, TLV_PAGE_SELECT page) {
+   if (codec > CODEC_B) codec = CODEC_B;  // clamp codec select
+   PageSelect[codec] = page;              // update current page for the codec
+   uint8_t reg = 0;                       // page select register address is 0
+   uint8_t data[2] = {reg, page};
+   int err = I2C_Write((codec == CODEC_A) ? I2C_CODEC_A : I2C_CODEC_B,
+                        CODEC_I2C_ADDR,
+                        data, 2);
+   return err;
+}
+
+
+
+