Esp8266Ex Module; Esp-Wroom-S2; Esp-Wroom-02 - Espressif Systems ESP8266 Series Hardware Design Manuallines

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3.
Espressif provides two types of modules, the SMD module (ESP-WROOM-02) and the DIP
module (ESP-WROOM-01). The modules have been improved to achieve the optimum RF
functionality. It is recommended that users use these modules for testing or further
development.

3.1. ESP-WROOM-S2

The module size is 16±0.2 mm x 23±0.2 mm x 3±0.15 mm (see Figure 1-1). The flash used
on this module is a 2-MB SPI flash connected to HSPI, with a package size of SOP 8-150
mil. The gain of the on-board PCB antenna is 2 dBi.
The ESP-WROOM-S2 works as the SDIO/SPI slave with the SPI speed of up to 8 Mbps.
For details of ESP-WROOM-S2, please refer to

3.2. ESP-WROOM-02

The module size is (18±0.2) mm x (20±0.2) mm x (3±0.15) mm. The type of flash used on
this module is an SPI flash with a package size of SOP 8-150 mil. The gain of the on-board
PCB antenna is 2 dBi.
Espressif

ESP8266EX Module

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Figure 3-1. ESP-WROOM-S2 Module
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ESP-WROOM-S2
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3. ESP8266EX Module
Datasheet.
2018.12