Espressif ESP32-LyraTD-SYNA
by Espressif
ESP32 board featuring Synaptics audio front end - ideal for enhanced voice detection and commands.

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Pinout
7 pins| Pin | GPIO | Labels | Status | Capabilities | Notes |
|---|---|---|---|---|---|
| 1 | 15 | TDOMTDOIO15 | strapping | adc · touch | JTAG header (TDO); shared with microSD CMD. ADC2_CH3, touch T3. |
| 2 | 13 | TCKMTCKIO13 | strapping | adc · touch | JTAG header (TCK); shared with microSD D3. ADC2_CH4, touch T4. |
| 3 | 12 | TDIMTDIIO12 | strapping | adc · touch | JTAG header (TDI); shared with microSD D2. Strapping pin (flash voltage). ADC2_CH5, touch T5. |
| 4 | 14 | TMSMTMSIO14 | strapping | adc · touch | JTAG header (TMS); shared with microSD CLK. ADC2_CH6, touch T6. |
| 5 | - | 5VVUSB | power | - | 5V input from the USB power port. |
| 6 | - | 3V3 | power | - | 3.3V regulated rail (onboard LDO). |
| 7 | - | GND | ground | - | Ground. |
Fine - with a little care
sampled at boot or shared with debug/serial| Pin | Label | What to know | Role |
|---|---|---|---|
| TDO | MTDO (GPIO15) | Keep HIGH during boot (internal PU); if LOW on reset, bootloader log is silenced and boot mode may change. | Strapping |
| TCK | MTCK (GPIO13) | Used for JTAG debugging (TCK); avoid using as GPIO if JTAG is needed. | Other |
| TDI | MTDI (GPIO12) | Keep LOW during boot (internal PD); pulling HIGH at reset selects 1.8V flash mode, causing flash brownout if 3.3V flash is used. | Strapping |
| TMS | MTMS (GPIO14) | Used for JTAG debugging (TMS); driving it as GPIO may interfere with JTAG or produce spurious signals at boot. | Other |
Pinout notes Across 7 pins, the Espressif ESP32-LyraTD-SYNA exposes 4 GPIO plus 5V , 3V3 and GND for power. On the analog side there are 4 ADC-capable pins for sensors and…
Across 7 pins, the Espressif ESP32-LyraTD-SYNA exposes 4 GPIO plus 5V, 3V3 and GND for power.
On the analog side there are 4 ADC-capable pins for sensors and battery monitoring and 4 capacitive-touch inputs.
4 of the exposed pins carry boot-time or system duties on the ESP32 (TDO, TCK, TDI and 1 more).
Getting started
flash your first firmware in ~2 minutesBoard: Esp32 Lyratd Syna
Flash Size: 4MB · DIO
Upload Speed: 921600
// blink
pinMode(8, OUTPUT);
digitalWrite(8, LOW); // on (often inverted)[env:esp32-lyratd-syna]
platform = espressif32
board = esp32dev
framework = arduino
monitor_speed = 115200
upload_speed = 921600esp32:
board: esp32dev
variant: esp32_lyratd_syna
framework:
type: esp-idf
# blink - GPIO8
output:
- platform: gpio
pin: 8
id: led_out
light:
- platform: binary
name: "LED"
output: led_outesptool.py --chip esp32 --port /dev/ttyACM0 \
write_flash 0x0 firmware.binSpecifications
ESP32About this board
At its core is the ESP32 - a dual-core Xtensa with both Bluetooth Classic and BLE.
Expect to pay about $25.00 - above the ~$20 typical for ESP32 boards.
Only 4 GPIO are broken out, where most ESP32 boards manage about 24 - worth checking the pinout covers what you need.
Onboard you'll find 8MB (QSPI) PSRAM, a microphone (Dual mic array), a speaker connector, an audio codec (CX20721), an amplifier and Reset/Boot/Play/Vol+/Vol-/Mute buttons.
The ESP32-LyraTD-SYNA is an advanced voice development board powered by the ESP32-WROVER module. It integrates Synaptics’ dual-microphone array for advanced voice processing, making it ideal for voice-controlled applications, smart assistants, and AI audio solutions. The board features Wi-Fi and Bluetooth connectivity, an audio codec, an amplifier, and multiple peripheral interfaces for seamless integration with smart home and embedded audio projects.
- Synaptics CX20921 far-field voice input DSP (AudioSmart)
- Integrated AudioSmart Class-D amplifier, 2.8W per channel
- Two-microphone array with noise reduction and echo cancellation
- 3.5mm earphone jack
Where to buy
prices are typical street prices
Resources
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