diff --git a/AudioConfigESP32.h b/AudioConfigESP32.h
index fd3fcba76..26d19476d 100644
--- a/AudioConfigESP32.h
+++ b/AudioConfigESP32.h
@@ -1,6 +1,9 @@
 #ifndef AUDIOCONFIGESP32_H
 #define AUDIOCONFIGESP32_H
 
+#include <driver/i2s.h>
+#include <soc/adc_channel.h>
+
 #if not IS_ESP32()
 #error This header should be included for ESP32 architecture, only
 #endif
@@ -9,37 +12,69 @@
 #error HIFI mode is not available for this CPU architecture (but check ESP32_AUDIO_OUT_MODE, and PDM_RESOLUTION)
 #endif
 
-// Audio output options
+// Audio IO options
 #define INTERNAL_DAC 1 // output using internal DAC via I2S, output on pin 26
 #define PT8211_DAC 2 // output using an external PT8211 DAC via I2S
-#define PDM_VIA_I2S 3 // output PDM coded sample on the I2S data pin (pin 33, by default, configurable, below)
+#define PDM_VIA_I2S 3  // output PDM coded sample on the I2S data pin (pin 33, by default, configurable, below)
+#define I2S_DAC_AND_I2S_ADC 4  // output using an external DAC , input with exteran ADC - both via I2S
 
-// Set output mode
+// Set output & input mode
 #define ESP32_AUDIO_OUT_MODE INTERNAL_DAC
 
 // For external I2S output, only: I2S_PINS
 #define ESP32_I2S_BCK_PIN 26
 #define ESP32_I2S_WS_PIN 25
 #define ESP32_I2S_DATA_PIN 33
+#define ESP32_I2S_DATA_PIN_IN 32  
 
-#include <driver/i2s.h>
+
+// Preferred I2S port: note that this might be taken into consideration if there is a choice
+// The Internal ADC and DAC only work on port 0 and can not be used at the same time!
 const i2s_port_t i2s_num = I2S_NUM_0;
+
+
+// Select the data range of the ADC
+//#define ADC_VALUE(in) (in) // no scaling
+#define ADC_VALUE(in) (0.015625*(in + 32768)) // scale to 0 to 1023
+
+// Optionally select a higher Sample Rate
+//#define ESP32_AUDIO_RATE 8000
+
+
+///--------------------------------------------------------------------------------------------------------
 /// User config end. Do not modify below this line
+///--------------------------------------------------------------------------------------------------------
+#if !EXTERNAL_AUDIO_OUTPUT
+#  if (ESP32_AUDIO_OUT_MODE == INTERNAL_DAC)
+#    define AUDIO_BITS 8
+#    define PDM_RESOLUTION 1
+#    define IS_INTERNAL_DAC
+#  elif (ESP32_AUDIO_OUT_MODE == PT8211_DAC  || ESP32_AUDIO_OUT_MODE == I2S_DAC_AND_I2S_ADC)
+#    define AUDIO_BITS 16
+#    define PDM_RESOLUTION 1
+#    define IS_I2S_DAC
+#  elif (ESP32_AUDIO_OUT_MODE == PDM_VIA_I2S)
+#    define AUDIO_BITS 16
+#    define PDM_RESOLUTION 4
+#    define IS_PDM
+#  else
+#  error Invalid output mode configured in AudioConfigESP32.h
+#  endif
 
-#if (ESP32_AUDIO_OUT_MODE == INTERNAL_DAC)
-#define AUDIO_BITS 8
-#define PDM_RESOLUTION 1
-#elif (ESP32_AUDIO_OUT_MODE == PT8211_DAC)
-#define AUDIO_BITS 16
-#define PDM_RESOLUTION 1
-#elif (ESP32_AUDIO_OUT_MODE == PDM_VIA_I2S)
-#define AUDIO_BITS 16
-#define PDM_RESOLUTION 4
-#else
-#error Invalid output mode configured in AudioConfigESP32.h
-#endif
+#  define AUDIO_BIAS ((uint16_t) 1<<(AUDIO_BITS-1))
+#  define BYPASS_MOZZI_OUTPUT_BUFFER true
+
+// Use defined rate as new AUDIO_RATE_PLATFORM_DEFAULT
+#  ifdef ESP32_AUDIO_RATE
+#    undef AUDIO_RATE_PLATFORM_DEFAULT 
+#    define AUDIO_RATE_PLATFORM_DEFAULT ESP32_AUDIO_RATE
+#  endif
 
-#define AUDIO_BIAS ((uint16_t) 1<<(AUDIO_BITS-1))
-#define BYPASS_MOZZI_OUTPUT_BUFFER true
+// If ADC is available we support getAudioInput()
+#  if ESP32_AUDIO_OUT_MODE == I2S_DAC_AND_I2S_ADC
+#    define USE_CUSTOM_AUDIO_INPUT
+int getAudioInput();
+#  endif
+#endif
 
 #endif        //  #ifndef AUDIOCONFIGESP_H
diff --git a/MozziGuts.cpp b/MozziGuts.cpp
index b6aad9dda..b9f65f31b 100644
--- a/MozziGuts.cpp
+++ b/MozziGuts.cpp
@@ -140,7 +140,7 @@ int mozziAnalogRead(uint8_t pin) {
 #endif
 }
 
-#if (USE_AUDIO_INPUT == true)
+#if (USE_AUDIO_INPUT == true && !defined(USE_CUSTOM_AUDIO_INPUT))
 static AudioOutputStorage_t audio_input; // holds the latest audio from input_buffer
 AudioOutputStorage_t getAudioInput() { return audio_input; }
 #endif
diff --git a/MozziGuts_impl_ESP32.hpp b/MozziGuts_impl_ESP32.hpp
index 7657eb62c..a5cb72efd 100644
--- a/MozziGuts_impl_ESP32.hpp
+++ b/MozziGuts_impl_ESP32.hpp
@@ -9,14 +9,19 @@
  * Attribution-NonCommercial-ShareAlike 4.0 International License.
  *
  */
-
 #if !(IS_ESP32())
 #  error "Wrong implementation included for this platform"
 #endif
+#include "AudioConfigESP32.h"
+#include <driver/i2s.h>   // for I2S-based output modes
+#include <driver/timer.h> // for EXTERNAL_AUDIO_OUTPUT
+
+static const char module[]="Mozzi-ESP32";
+
+
+// ////// BEGIN analog input code ////////
+#define getADCReading() 0;
 
-////// BEGIN analog input code ////////
-//#define MOZZI_FAST_ANALOG_IMPLEMENTED // not yet
-#define getADCReading() 0
 #define channelNumToIndex(channel) channel
 uint8_t adcPinToChannelNum(uint8_t pin) {
   return pin;
@@ -36,32 +41,110 @@ void setupMozziADC(int8_t speed) {
 ////// END analog input code ////////
 
 
+#if (EXTERNAL_AUDIO_OUTPUT) // for external audio output, set up a timer running a audio rate
+
+void CACHED_FUNCTION_ATTR timer0_audio_output_isr(void *) {
+  TIMERG0.int_clr_timers.t0 = 1;
+  TIMERG0.hw_timer[0].config.alarm_en = 1;
+  defaultAudioOutput();
+}
 
 
-//// BEGIN AUDIO OUTPUT code ///////
-#include <driver/i2s.h>   // for I2S-based output modes
-#include <driver/timer.h> // for EXTERNAL_AUDIO_OUTPUT
+static void startAudio() {
+  static intr_handle_t s_timer_handle;
+  const int div = 2;
+  timer_config_t config = {
+    .alarm_en = (timer_alarm_t)true,
+    .counter_en = (timer_start_t)false,
+    .intr_type = (timer_intr_mode_t) TIMER_INTR_LEVEL,
+    .counter_dir = TIMER_COUNT_UP,
+    .auto_reload = (timer_autoreload_t) true,
+    .divider = div // For max available precision: The APB_CLK clock signal is running at 80 MHz, i.e. 2/80 uS per tick
+                 // Min acceptable value is 2
+  };
+  timer_init(TIMER_GROUP_0, TIMER_0, &config);
+  timer_set_counter_value(TIMER_GROUP_0, TIMER_0, 0);
+  timer_set_alarm_value(TIMER_GROUP_0, TIMER_0, 80000000UL / AUDIO_RATE / div);
+  timer_enable_intr(TIMER_GROUP_0, TIMER_0);
+  timer_isr_register(TIMER_GROUP_0, TIMER_0, &timer0_audio_output_isr, nullptr, 0, &s_timer_handle);
+  timer_start(TIMER_GROUP_0, TIMER_0);
+}
+
+void stopMozzi() {
+  timer_pause(TIMER_GROUP_0, TIMER_0);
+  timer_disable_intr(TIMER_GROUP_0, TIMER_0);
+}
+
+#else // I2S Output
 
-#if (EXTERNAL_AUDIO_OUTPUT != true)
-#  include "AudioConfigESP32.h"
 // On ESP32 we cannot test wether the DMA buffer has room. Instead, we have to use a one-sample mini buffer. In each iteration we
 // _try_ to write that sample to the DMA buffer, and if successful, we can buffer the next sample. Somewhat cumbersome, but works.
 // TODO: Should ESP32 gain an implemenation of i2s_available(), we should switch to using that, instead.
 static bool _esp32_can_buffer_next = true;
-#  if (ESP32_AUDIO_OUT_MODE == INTERNAL_DAC)
+#  if defined(IS_INTERNAL_DAC)
 static uint16_t _esp32_prev_sample[2];
-#    define ESP_SAMPLE_SIZE (2*sizeof(uint16_t))
-#  elif (ESP32_AUDIO_OUT_MODE == PT8211_DAC)
+#  elif defined(IS_I2S_DAC)
 static int16_t _esp32_prev_sample[2];
-#    define ESP_SAMPLE_SIZE (2*sizeof(int16_t))
-#  elif (ESP32_AUDIO_OUT_MODE == PDM_VIA_I2S)
+#  elif defined(IS_PDM)
 static uint32_t _esp32_prev_sample[PDM_RESOLUTION];
-#    define ESP_SAMPLE_SIZE (PDM_RESOLUTION*sizeof(uint32_t))
 #  endif
 
+
+/// Make sure that we provide a supported port
+int getI2SPort(){
+  switch (ESP32_AUDIO_OUT_MODE){
+    case INTERNAL_DAC: 
+      return 0;
+    case PDM_VIA_I2S:  
+      return 0;
+    case PT8211_DAC:     
+      return i2s_num;
+    case I2S_DAC_AND_I2S_ADC:  
+      return i2s_num;
+  }
+  ESP_LOGE(module, "%s - %s", __func__, "ESP32_AUDIO_OUT_MODE invalid");
+  return -1;
+}
+
+
+/// Determine the I2S Output Mode (and input mode if on same port)
+int getI2SMode(){
+  switch (ESP32_AUDIO_OUT_MODE){
+    case INTERNAL_DAC: 
+      ESP_LOGD(module, "%s: %s", __func__, "I2S_MODE_MASTER | I2S_MODE_TX | I2S_MODE_DAC_BUILT_IN");
+      return I2S_MODE_MASTER | I2S_MODE_TX | I2S_MODE_DAC_BUILT_IN;
+    case PDM_VIA_I2S:  
+      ESP_LOGD(module, "%s: %s", __func__, "I2S_MODE_MASTER | I2S_MODE_TX | I2S_MODE_PDM");
+      return I2S_MODE_MASTER | I2S_MODE_TX | I2S_MODE_PDM;
+    case PT8211_DAC:     
+      ESP_LOGD(module, "%s: %s", __func__, "I2S_MODE_MASTER | I2S_MODE_TX");
+      return I2S_MODE_MASTER | I2S_MODE_TX;
+    case I2S_DAC_AND_I2S_ADC:  
+      ESP_LOGD(module, "%s: %s", __func__, "I2S_MODE_MASTER | I2S_MODE_TX | I2S_MODE_RX");
+      return I2S_MODE_MASTER | I2S_MODE_TX | I2S_MODE_RX;
+  }
+   ESP_LOGE(module, "%s: %s", __func__, "ESP32_AUDIO_OUT_MODE invalid");
+ return -1;
+}
+
+/// @brief  Reads a sample from the I2S buffer. I2S is stereo, so we combine the result to one single sample
+int getAudioInput() {
+  static const int i2s_port = getI2SPort();
+  if (i2s_port==-1) return 0;
+
+  int16_t tmp[2];
+  size_t result;
+  esp_err_t rc = i2s_read((i2s_port_t)i2s_port, tmp, sizeof(tmp), &result, portMAX_DELAY);
+  return ADC_VALUE((tmp[0]+tmp[1]) / 2);
+}
+
+
 inline bool esp32_tryWriteSample() {
+  static i2s_port_t port = (i2s_port_t) getI2SPort();
   size_t bytes_written;
-  i2s_write(i2s_num, &_esp32_prev_sample, ESP_SAMPLE_SIZE, &bytes_written, 0);
+  int write_len = sizeof(_esp32_prev_sample);
+  i2s_write(port, &_esp32_prev_sample, write_len, &bytes_written, 0);
+  //ESP_LOGD(module, "%s port:%d, len: %d, written: %d, value: %d", __func__, port, write_len, bytes_written, _esp32_prev_sample[0]);
   return (bytes_written != 0);
 }
 
@@ -72,7 +155,7 @@ inline bool canBufferAudioOutput() {
 }
 
 inline void audioOutput(const AudioOutput f) {
-#  if (ESP32_AUDIO_OUT_MODE == INTERNAL_DAC)
+#  if defined(IS_INTERNAL_DAC)
   _esp32_prev_sample[0] = (f.l() + AUDIO_BIAS) << 8;
 #    if (AUDIO_CHANNELS > 1)
   _esp32_prev_sample[1] = (f.r() + AUDIO_BIAS) << 8;
@@ -80,7 +163,7 @@ inline void audioOutput(const AudioOutput f) {
   // For simplicity of code, even in mono, we're writing stereo samples
   _esp32_prev_sample[1] = _esp32_prev_sample[0];
 #    endif
-#  elif (ESP32_AUDIO_OUT_MODE == PDM_VIA_I2S)
+#  elif defined(IS_PDM)
   for (uint8_t i=0; i<PDM_RESOLUTION; ++i) {
     _esp32_prev_sample[i] = pdmCode32(f.l() + AUDIO_BIAS);
   }
@@ -91,72 +174,63 @@ inline void audioOutput(const AudioOutput f) {
 #  endif
   _esp32_can_buffer_next = esp32_tryWriteSample();
 }
-#endif
 
-#if (BYPASS_MOZZI_OUTPUT_BUFFER != true)
-void CACHED_FUNCTION_ATTR timer0_audio_output_isr(void *) {
-  TIMERG0.int_clr_timers.t0 = 1;
-  TIMERG0.hw_timer[0].config.alarm_en = 1;
-  defaultAudioOutput();
-}
-#endif
+static void startI2SAudio(i2s_port_t port, int mode){
+  ESP_LOGI(module, "%s: port=%d, mode=0x%x, rate=%d", __func__, port, mode, AUDIO_RATE * PDM_RESOLUTION);
 
-static void startAudio() {
-#if (BYPASS_MOZZI_OUTPUT_BUFFER != true)  // for external audio output, set up a timer running a audio rate
-  static intr_handle_t s_timer_handle;
-  const int div = 2;
-  timer_config_t config = {
-    .alarm_en = (timer_alarm_t)true,
-    .counter_en = (timer_start_t)false,
-    .intr_type = (timer_intr_mode_t) TIMER_INTR_LEVEL,
-    .counter_dir = TIMER_COUNT_UP,
-    .auto_reload = (timer_autoreload_t) true,
-    .divider = div // For max available precision: The APB_CLK clock signal is running at 80 MHz, i.e. 2/80 uS per tick
-                 // Min acceptable value is 2
-  };
-  timer_init(TIMER_GROUP_0, TIMER_0, &config);
-  timer_set_counter_value(TIMER_GROUP_0, TIMER_0, 0);
-  timer_set_alarm_value(TIMER_GROUP_0, TIMER_0, 80000000UL / AUDIO_RATE / div);
-  timer_enable_intr(TIMER_GROUP_0, TIMER_0);
-  timer_isr_register(TIMER_GROUP_0, TIMER_0, &timer0_audio_output_isr, nullptr, 0, &s_timer_handle);
-  timer_start(TIMER_GROUP_0, TIMER_0);
-
-#else
-  static const i2s_config_t i2s_config = {
-#  if (ESP32_AUDIO_OUT_MODE == PT8211_DAC) || (ESP32_AUDIO_OUT_MODE == PDM_VIA_I2S)
-    .mode = (i2s_mode_t)(I2S_MODE_MASTER | I2S_MODE_TX),
-#  elif (ESP32_AUDIO_OUT_MODE == INTERNAL_DAC)
-    .mode = (i2s_mode_t)(I2S_MODE_MASTER | I2S_MODE_TX | I2S_MODE_DAC_BUILT_IN),
-#  endif
+  static i2s_config_t i2s_config = {
+    .mode = (i2s_mode_t)mode,
     .sample_rate = AUDIO_RATE * PDM_RESOLUTION,
     .bits_per_sample = I2S_BITS_PER_SAMPLE_16BIT,  // only the top 8 bits will actually be used by the internal DAC, but using 8 bits straight away seems buggy
     .channel_format = I2S_CHANNEL_FMT_RIGHT_LEFT,  // always use stereo output. mono seems to be buggy, and the overhead is insignifcant on the ESP32
-    .communication_format = (i2s_comm_format_t)(I2S_COMM_FORMAT_I2S | I2S_COMM_FORMAT_I2S_LSB),  // this appears to be the correct setting for internal DAC and PT8211, but not for other dacs
+    .communication_format = (i2s_comm_format_t)(I2S_COMM_FORMAT_STAND_I2S),  // this appears to be the correct setting for internal DAC and PT8211, but not for other dacs
     .intr_alloc_flags = 0, // default interrupt priority
     .dma_buf_count = 8,    // 8*128 bytes of buffer corresponds to 256 samples (2 channels, see above, 2 bytes per sample per channel)
     .dma_buf_len = 128,
-    .use_apll = false
+    .use_apll = false,
   };
 
-  i2s_driver_install(i2s_num, &i2s_config, 0, NULL);
-#  if (ESP32_AUDIO_OUT_MODE == PT8211_DAC) || (ESP32_AUDIO_OUT_MODE == PDM_VIA_I2S)
-  static const i2s_pin_config_t pin_config = {
-    .bck_io_num = ESP32_I2S_BCK_PIN,
-    .ws_io_num = ESP32_I2S_WS_PIN,
-    .data_out_num = ESP32_I2S_DATA_PIN,
-    .data_in_num = -1
-  };
-  i2s_set_pin((i2s_port_t)i2s_num, &pin_config);
-#  elif (ESP32_AUDIO_OUT_MODE == INTERNAL_DAC)
-  i2s_set_pin((i2s_port_t)i2s_num, NULL);
-  i2s_set_dac_mode(I2S_DAC_CHANNEL_BOTH_EN);
-#  endif
-  i2s_zero_dma_buffer((i2s_port_t)i2s_num);
+  // install i2s driver
+  if (i2s_driver_install(port, &i2s_config, 0, NULL)!=ESP_OK){
+    ESP_LOGE(module, "%s - %s : %d", __func__, "i2s_driver_install", port);
+  }
 
-#endif
+  // Internal DAC
+  if (ESP32_AUDIO_OUT_MODE==INTERNAL_DAC){
+    if (i2s_set_pin(port, NULL)!=ESP_OK) {
+        ESP_LOGE(module, "%s - %s", __func__, "i2s_set_pin");
+    }
+    if (i2s_set_dac_mode(I2S_DAC_CHANNEL_BOTH_EN)!=ESP_OK) {
+        ESP_LOGE(module, "%s - %s", __func__, "i2s_set_dac_mode");
+    }
+  // Regular I2S
+  } else {
+    static const i2s_pin_config_t pin_config = {
+      .bck_io_num = ESP32_I2S_BCK_PIN,
+      .ws_io_num = ESP32_I2S_WS_PIN,
+      .data_out_num = ESP32_I2S_DATA_PIN,
+      .data_in_num = ESP32_I2S_DATA_PIN_IN,
+    };
+    if (i2s_set_pin(port, &pin_config)!=ESP_OK) {
+      ESP_LOGE(module, "%s - %s", __func__, "i2s_set_pin");
+    }
+  }
+  i2s_zero_dma_buffer(port);
+}
+
+/// Use I2S for the Output and Input
+static void startAudio() {
+  // start output
+  i2s_port_t port = (i2s_port_t)getI2SPort();
+  startI2SAudio(port, getI2SMode());
 }
 
 void stopMozzi() {
-  // TODO: implement me
+  i2s_port_t port = (i2s_port_t)getI2SPort();
+  i2s_stop(port);
+  i2s_driver_uninstall(port);
 }
+
+#endif
+
 //// END AUDIO OUTPUT code ///////
diff --git a/README.md b/README.md
index 5bcdc23d9..1fd36879d 100644
--- a/README.md
+++ b/README.md
@@ -318,6 +318,9 @@ port by Dieter Vandoren and Thomas Friedrichsmeier
     - Output (DATA) pin can be configured in AudioConfigESP32.h. Default 33. Note that the BCK and WS pins are also used in this mode.
     - The PDM_RESOLUTION parameter can be used to reduce noise at the cost of more CPU power.
     - Mono, only.
+  - I2S_DAC_AND_I2S_ADC: Output is sent via I2S in a format, Input is read from I2S in douplex mode.
+    - 16 bits resolution, mono or stereo. Remember to shift your audio accordingly.
+    - I2S ins can be configured in AudioConfigESP32.h. Default is BCK: 26, WS: 15, DATA: 33, DATA_IN: 32.
 - "HIFI_MODE" is not currently implemented, but could conceivably be realized for the INTERNAL_DAC mode. Patches welcome.
 - WIFI-activity not yet tested, but likely the same notes as for ESP8266 apply. Consider turning off WIFI.
 - The implementation of audioTicks() may be slightly inaccurate on this platform.