ESP-WROOM-02 vs ESP32-S2-SOLO-2
ESP-WROOM-02
WROOM · ESP8266 · Active
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ESP32-S2-SOLO-2
SOLO · ESP32-S2 · Active
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Every figure here is checked against Espressif’s official datasheets. We’ve taken every care to keep it accurate — but datasheets are dense and mistakes happen, so if something looks off, please report it.
Which should you choose?
These run different SoCs (ESP8266 vs ESP32-S2), so they differ in CPU, wireless and peripherals — not just packaging.
Choose ESP-WROOM-02 if you need
- smaller footprint (18×20 mm)
Choose ESP32-S2-SOLO-2 if you need
- faster CPU (240 MHz, Xtensa LX7)
- PSRAM for camera frames, audio buffers and LVGL/large displays
- larger flash option (up to 16 MB) for bigger firmware and OTA
- native USB-OTG — act as a USB device/host without a USB-UART chip
- more usable GPIO (36 vs 11)
Size, to scale
- ESP-WROOM-02 — 18×20 mm
- ESP32-S2-SOLO-2 — 18×25.5 mm
Spec differences at a glance
- CPU: ESP-WROOM-02 Xtensa L106, 1-core · ESP32-S2-SOLO-2 Xtensa LX7, 1-core
- Max clock: ESP-WROOM-02 160 MHz · ESP32-S2-SOLO-2 240 MHz
- SRAM: ESP-WROOM-02 — KB · ESP32-S2-SOLO-2 320 KB
- ROM: ESP-WROOM-02 — KB · ESP32-S2-SOLO-2 128 KB
- Flash options: ESP-WROOM-02 2 MB · ESP32-S2-SOLO-2 4 / 8 / 16 MB
- PSRAM: ESP-WROOM-02 None · ESP32-S2-SOLO-2 2 MB (quad)
- Co-processor: ESP-WROOM-02 none · ESP32-S2-SOLO-2 ULP-RISC-V
- Usable GPIO: ESP-WROOM-02 11 · ESP32-S2-SOLO-2 36
- ADC: ESP-WROOM-02 1× 10-bit · ESP32-S2-SOLO-2 20× 12-bit
- USB: ESP-WROOM-02 USB-Serial(external) · ESP32-S2-SOLO-2 USB-OTG
- UART / SPI / I²C / I²S: ESP-WROOM-02 2 / 1 / 1 / 1 · ESP32-S2-SOLO-2 2 / 2 / 2 / 1
- TWAI (CAN): ESP-WROOM-02 No · ESP32-S2-SOLO-2 Yes
- SD/MMC: ESP-WROOM-02 Yes · ESP32-S2-SOLO-2 No
- Touch: ESP-WROOM-02 0 · ESP32-S2-SOLO-2 14
- Operating voltage: ESP-WROOM-02 2.7-3.6 V · ESP32-S2-SOLO-2 3.0-3.6 V
- Deep sleep: ESP-WROOM-02 20 µA · ESP32-S2-SOLO-2 — µA
- Dimensions: ESP-WROOM-02 18 × 20 × 2.8 mm · ESP32-S2-SOLO-2 18 × 25.5 × 3.1 mm
- Pin count: ESP-WROOM-02 18 · ESP32-S2-SOLO-2 41
- Secure boot: ESP-WROOM-02 No · ESP32-S2-SOLO-2 Yes
- Flash encryption: ESP-WROOM-02 No · ESP32-S2-SOLO-2 Yes
- Crypto: ESP-WROOM-02 — · ESP32-S2-SOLO-2 AES, SHA, RSA, HMAC, RNG
- Digital signature: ESP-WROOM-02 No · ESP32-S2-SOLO-2 Yes
Compute & memory
⚑ flag an error| ESP-WROOM-02 | ESP32-S2-SOLO-2 | |
|---|---|---|
| CPU≠ | Xtensa L106, 1-core | Xtensa LX7, 1-core |
| Max clock≠ | 160 MHz | 240 MHz |
| SRAM≠ | — KB | 320 KB |
| ROM≠ | — KB | 128 KB |
| Flash options≠ | 2 MB | 4 / 8 / 16 MB |
| PSRAM≠ | None | 2 MB (quad) |
| Co-processor≠ | none | ULP-RISC-V |
Wireless
⚑ flag an error| ESP-WROOM-02 | ESP32-S2-SOLO-2 | |
|---|---|---|
| Wi-Fi | Wi-Fi 4 | Wi-Fi 4 |
| Wi-Fi bands | 2.4GHz | 2.4GHz |
| Bluetooth | — | — |
| 802.15.4 (Thread/Zigbee) | No | No |
| Antenna | PCB | PCB |
Peripherals & I/O
⚑ flag an error| ESP-WROOM-02 | ESP32-S2-SOLO-2 | |
|---|---|---|
| Usable GPIO≠ | 11 | 36 |
| ADC≠ | 1× 10-bit | 20× 12-bit |
| USB≠ | USB-Serial(external) | USB-OTG |
| UART / SPI / I²C / I²S≠ | 2 / 1 / 1 / 1 | 2 / 2 / 2 / 1 |
| TWAI (CAN)≠ | No | Yes |
| SD/MMC≠ | Yes | No |
| Ethernet MAC | No | No |
| Touch≠ | 0 | 14 |
Power
⚑ flag an error| ESP-WROOM-02 | ESP32-S2-SOLO-2 | |
|---|---|---|
| Operating voltage≠ | 2.7-3.6 V | 3.0-3.6 V |
| Deep sleep≠ | 20 µA | — µA |
Physical
⚑ flag an error| ESP-WROOM-02 | ESP32-S2-SOLO-2 | |
|---|---|---|
| Dimensions≠ | 18 × 20 × 2.8 mm | 18 × 25.5 × 3.1 mm |
| Pin count≠ | 18 | 41 |
| Temp range | -40 to 85 °C | -40 to 85 °C |
| Mounting | SMD castellated | SMD castellated |
| Lifecycle | Active | Active |
Security
⚑ flag an error| ESP-WROOM-02 | ESP32-S2-SOLO-2 | |
|---|---|---|
| Secure boot≠ | No | Yes |
| Flash encryption≠ | No | Yes |
| Crypto≠ | — | AES, SHA, RSA, HMAC, RNG |
| Digital signature≠ | No | Yes |
| TRNG | Yes | Yes |