Single-Channel I2S Microphone (T5848)

The G-Sense Single-Channel Microphone (T5848) is a high-performance, bottom-port digital I2S MEMS microphone module powered by the TDK InvenSense T5848 IC. Designed specifically for always-on voice recognition, keyword spotting, edge AI, and ultra-low-power IoT applications, it combines studio-quality dynamic range with ground-breaking power efficiency. Unlike traditional MEMS microphones, the T5848 includes built-in hardware Acoustic Activity Detect (AAD). This feature monitors the acoustic environment while sipping as little as 20 µA, instantly waking your microcontroller from deep sleep via the dedicated WAKE interrupt pad whenever sound is detected.

Pin Configuration

The module exposes a 6-pin main connection header for standard I2S communication, along with dedicated auxiliary solder pads on the PCB for advanced power and wake features.

Main Header Pinout

Pin	Type	Function	Connection on GLYPH-C3
VCC	Power	Module supply input (3.3V or 1.8V)	3.3V
GND	Power	Common ground	GND
SCK	Input	I²S Serial Bit Clock (BCLK)	GPIO 6 (MO)
WS	Input	I²S Word Select / Frame Sync (LRCK)	GPIO 20 (RX)
SD	Output	I²S Serial Audio Data Output	GPIO 7 (MI)
LR	Input	Left/Right Channel Select (LOW = Left, HIGH = Right)	GPIO 21 (TX)

Additional Solder Pads on PCB

The PCB features three dedicated breakout solder pads for low-power edge computing and custom power configurations:

Solder Pad	Function & Description
WAKE	Acoustic Activity Detect (AAD) Interrupt: Active-high output signal that flags acoustic energy detection. Connect this pad to an external interrupt or RTC wake-up GPIO on the GLYPH board to wake the system from deep sleep.
THSEL	Threshold Select: Configures the acoustic detection threshold / sensitivity of the AAD engine, determining the sound pressure level required to trigger the WAKE pin.
1V8	1.8V Power Rail: Direct access to the microphone’s native 1.8V operating rail, enabling true ultra-low-power operation and direct compatibility with 1.8V low-power microcontrollers and sensor hubs.

Key Features

TDK InvenSense T5848 MEMS IC: Cutting-edge multi-mode digital microphone with bottom acoustic port.
Direct I²S Digital Audio: Connects straight to the ESP32 without requiring an external audio codec or analog circuitry.
Ultra-Low-Power Acoustic Activity Detect (AAD): Listens for sound and voices in edge-processing mode at just 20 µA.
Hardware WAKE & THSEL Pads: Easily trigger wake-up interrupts on voice/tap events with configurable detection thresholds.
1.8V Native Rail Breakout: Dedicated solder pad for 1.8V power rails and energy-harvesting IoT nodes.
High Acoustic Overload Point (AOP): Up to 133 dB SPL, preventing distortion in noisy and high-volume environments.
High Signal-to-Noise Ratio (SNR): 68 dBA in High Quality Mode for clean speech recognition and audio recording.
Multi-Mode Power Management: High Quality, Low Power (AlwaysOn), and Sleep modes with minimal latency.

Application

Voice-Activated IoT Nodes: Wake-on-sound home automation and smart assistants.
Keyword Spotting & Edge AI: On-device voice classification with ESP32-C3 / ESP-SR.
Security & Glass Break Detection: Acoustic event triggers using the hardware AAD engine.
Audio Recorders & Smart Wearables: Low-power audio capture and sound monitoring.
Industrial Condition Monitoring: Acoustic anomaly detection in rotating machinery.

Step 1: Hardware Required

Pcbcupid GLYPH-C3 board (or any GLYPH ESP32 series board)
G-Sense 1-Channel Microphone (T5848) Module
Breadboard & Jumper wires
USB-C Cable for power and serial programming

Step 2: Circuit Diagram

Connect the module to the GLYPH-C3 as follows:

VCC → GLYPH-C3 3.3V
GND → GLYPH-C3 GND
SCK → GLYPH-C3 GPIO 6 (MO)
WS → GLYPH-C3 GPIO 20 (RX)
SD → GLYPH-C3 GPIO 7 (MI)
LR → GLYPH-C3 GPIO 21 (TX) (driven LOW in software for Left Channel)

(Optional): Connect the WAKE solder pad to an available GPIO (e.g., GPIO 3) if utilizing wake-on-sound interrupts.

Step 3: Code Setup

Open the Arduino IDE and paste the following sketch. This sketch uses the native ESP-IDF I2S driver built into the ESP32 Arduino Core to configure the master I2S receiver, read 32-bit digital audio samples from the T5848, and print sample amplitudes to the Serial Monitor:

#include <driver/i2s.h>

#define I2S_SCK_PIN   6    // MO
#define I2S_WS_PIN    20   // RX
#define I2S_SD_PIN    7    // MI
#define LR_PIN        21   // TX

#define SAMPLE_RATE   16000
#define I2S_PORT      I2S_NUM_0

void setupI2S() {
  i2s_config_t i2s_config = {
    .mode = (i2s_mode_t)(I2S_MODE_MASTER | I2S_MODE_RX),
    .sample_rate = SAMPLE_RATE,
    .bits_per_sample = I2S_BITS_PER_SAMPLE_32BIT,
    .channel_format = I2S_CHANNEL_FMT_ONLY_LEFT,
    .communication_format = I2S_COMM_FORMAT_STAND_I2S,
    .intr_alloc_flags = ESP_INTR_FLAG_LEVEL1,
    .dma_buf_count = 4,
    .dma_buf_len = 256,
    .use_apll = false,
    .tx_desc_auto_clear = false,
    .fixed_mclk = 0
  };

  i2s_pin_config_t pin_config = {
    .bck_io_num = I2S_SCK_PIN,
    .ws_io_num = I2S_WS_PIN,
    .data_out_num = I2S_PIN_NO_CHANGE,
    .data_in_num = I2S_SD_PIN
  };

  esp_err_t r1 = i2s_driver_install(I2S_PORT, &i2s_config, 0, NULL);
  esp_err_t r2 = i2s_set_pin(I2S_PORT, &pin_config);
  Serial.printf("i2s_driver_install=%d  i2s_set_pin=%d\n", r1, r2);
  i2s_zero_dma_buffer(I2S_PORT);
}

void setup() {
  Serial.begin(115200);
  delay(500);

  pinMode(LR_PIN, OUTPUT);
  digitalWrite(LR_PIN, LOW);   // selects left channel

  setupI2S();
  Serial.println("T5848 mic ready. Tap/blow on the mic now.");
}

void loop() {
  int32_t buffer[8];
  size_t bytesRead = 0;
  i2s_read(I2S_PORT, buffer, sizeof(buffer), &bytesRead, portMAX_DELAY);

  static uint32_t lastPrint = 0;
  if (millis() - lastPrint > 500) {
    lastPrint = millis();
    Serial.printf("bytesRead=%d  raw samples: %ld %ld %ld %ld\n",
                  bytesRead, buffer[0], buffer[1], buffer[2], buffer[3]);
  }
}

Step 4: Upload the Code

Connect your GLYPH-C3 to your computer via USB-C.
In the Arduino IDE, configure the board settings:
- Go to Tools → Board → esp32 → Pcbcupid GLYPH C3.

For Pcbcupid GLYPH C3 to appear under Tools > Board > esp32, the esp32 board package installed in the Arduino IDE must be version 3.1.0 or higher.

Select your COM port under Tools → Port.
Set Tools → USB CDC On Boot → Enabled.

If USB CDC on Boot is disabled, serial debug messages will not appear in the Serial Monitor.

Click Upload (or press Ctrl + U).

Step 5: Observe the Output

Once uploaded, open the Serial Monitor at 115200 baud.
You will see the initialization status followed by the live 32-bit sample values:

Welcome

Modules

Enclosure

Single-Channel I2S Microphone (T5848)

Pin Configuration

Main Header Pinout

Additional Solder Pads on PCB

Key Features

Application

Step 1: Hardware Required

Step 2: Circuit Diagram

Step 3: Code Setup

Step 4: Upload the Code

Step 5: Observe the Output

​Pin Configuration

​Main Header Pinout

​Additional Solder Pads on PCB

​Key Features

​Application

​Step 1: Hardware Required

​Step 2: Circuit Diagram

​Step 3: Code Setup

​Step 4: Upload the Code

​Step 5: Observe the Output

Pin Configuration

Main Header Pinout

Additional Solder Pads on PCB

Key Features

Application

Step 1: Hardware Required

Step 2: Circuit Diagram

Step 3: Code Setup

Step 4: Upload the Code

Step 5: Observe the Output