Espressif ESP32-Korvo
Versatile audio development platform for ESP32 - supports multiple audio codecs and mic inputs for AI voice tasks.
Espressif ESP32-Korvo Pinout
8 pins
| Pin | GPIO | Labels | Status | Capabilities | Notes |
|---|---|---|---|---|---|
| 1 | 14 | IO14SDIO_CLK | strapping | adc · touch | Reserved SDIO 1-bit expansion/stacking header (JP2, "communicate with another esp system"); footprint present, unpopulated on V1.1. Touch T6 / ADC2_CH6. |
| 2 | 15 | IO15SDIO_CMD | strapping | adc · touch | Reserved SDIO 1-bit expansion/stacking header (JP2); ESP32 strapping pin. Touch T3 / ADC2_CH3. |
| 3 | 2 | IO2SDIO_D0 | strapping | adc · touch | Reserved SDIO 1-bit expansion/stacking header (JP2); ESP32 strapping pin. Touch T2 / ADC2_CH2. |
| 4 | 4 | IO4SDIO_D1 | safe | adc · touch | Reserved SDIO 1-bit expansion/stacking header (JP2). Touch T0 / ADC2_CH0. |
| 5 | 1 | TXD0TX | uart | uart | UART0 TX; routed to the CP2102N USB-UART bridge (Micro-USB) and to the reserved 3-pin UART/download header next to JP2. |
| 6 | 3 | RXD0RX | uart | uart | UART0 RX; routed to the CP2102N USB-UART bridge (Micro-USB) and to the reserved 3-pin UART/download header next to JP2. |
| 7 | - | 3V3 | power | - | 3.3V rail (AMS1117-3.3) exposed on the reserved expansion header (VDD33). |
| 8 | - | GND | ground | - | Ground, present on the expansion/UART headers. |
Start with these
1 pins with no boot or system involvementFreely assignable - no strapping, flash, USB or JTAG duties. Ideal first picks for buttons, sensors and LEDs.
Fine - with a little care
5 pins · 5 things to knowIO14 JTAG mode select pin (TMS); also HSPI CLK and PWM-capable GPIO. JTAG
Used for JTAG debugging (TMS); driving it as GPIO may interfere with JTAG or produce spurious signals at boot.
IO15 Bootstrapping pin; JTAG TDO; controls UART0 boot log output; also HSPICS0 (secondary SPI CS). Strapping
Keep HIGH during boot (internal PU); if LOW on reset, bootloader log is silenced and boot mode may change.
IO2 Bootstrapping pin (must be low or floating at reset); internal pull-down. Strapping
If driven HIGH on reset (while IO0 is LOW), selects an unsupported SDIO boot mode, causing boot failure.
TXD0GPIO1 Default UART0 TX pin for USB-serial programming and console. UART
Connected to on-board USB-UART for uploading and logs; drives serial output at boot, so using as GPIO can disrupt programming or console.
RXD0GPIO3 Default UART0 RX pin for USB-serial programming (console input). UART
Used for receiving data from USB-UART (programming); also pulled HIGH at boot for console communication, so using as GPIO can disrupt uploads.
The Espressif ESP32-Korvo breaks out 8 pins in total: 6 GPIO for your project, with 3V3 and GND handling power.
Peripheral wiring is straightforward: TX/RX on GPIO1 and GPIO3 cover serial logging and flashing.
Beyond plain digital I/O you get 4 ADC-capable pins for sensors and battery monitoring and 4 capacitive-touch inputs.
5 of the exposed pins carry boot-time or system duties on the ESP32 (IO14, IO15, IO2 and 2 more) - check the guidance above before wiring anything to them. IO4 is free of any such role - the safest first picks.
Getting started
flash your first firmware in ~2 minutesBoard: ESP32 Wrover Module Flash Size: 16MB (128Mb) Flash Mode: DIO PSRAM: QSPI PSRAM Partition Scheme: 16M Flash (3MB APP/9.9MB FATFS) Upload Speed: 921600
// toggle GPIO4 - wire an LED and resistor to it
void setup() {
pinMode(4, OUTPUT);
}
void loop() {
digitalWrite(4, HIGH); delay(500);
digitalWrite(4, LOW); delay(500);
}[env:esp32-korvo]
platform = espressif32
board = esp32dev
framework = arduino
monitor_speed = 115200
upload_speed = 921600
board_build.arduino.memory_type = qio_qspi
build_flags = -DBOARD_HAS_PSRAMesp32dev - or type it after board =.esp32:
board: esp32dev
variant: esp32
framework:
type: esp-idf
psram:
mode: quad
speed: 80MHz
# blink - GPIO4
output:
- platform: gpio
pin: 4
id: led_out
light:
- platform: binary
name: "LED"
output: led_outesp32dev (same ids as PlatformIO).esptool.py --chip esp32 --port /dev/ttyACM0 \
--baud 921600 write_flash 0x1000 firmware.bin--port = your /dev/tty* (macOS/Linux) or COMx (Windows).Specifications
ESP32 · vs other ESP32 chips →About this board
Inside sits the ESP32 - a dual-core Xtensa with both Bluetooth Classic and BLE.
At $40.00 it's on the expensive side for an ESP32 board - most land around $20.
Only 6 GPIO are broken out, where most ESP32 boards manage about 24 - worth checking the pinout covers what you need.
Around the module: 8MB (QSPI) PSRAM, a microSD slot, a microphone (Triple analog microphone array), a speaker connector, an audio codec (ES8311), an amplifier (NS4150), an addressable RGB LED (GPIO33), battery charging (AP5056) and Reset/Boot/Play/Set/Vol-/Vol+/Mode/Rec buttons.
The ESP32-Korvo is a powerful AI voice development board based on the ESP32-WROVER module. Designed for speech recognition and audio applications, it integrates an audio codec, multiple microphone inputs, and a DSP for advanced audio processing. The board supports Wi-Fi and Bluetooth connectivity, making it ideal for AI-powered voice assistants, smart home applications, and audio streaming projects.
- ES7210 four-channel audio ADC captures the three-microphone array
- On-board 3.5 mm earphone output
Where to buy
prices are typical street pricesResources
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