The ESP-WROOM-02D is a WiFi module manufactured by Espressif which has an integrated low power 32-bit MCU, 802.11b/g/n Wi-Fi Transceiver, associated software stacks, and power management modules. The module uses an ESP8266EX as the main processor, 16Mbits SPI flash with pre-loaded program, and a PCB antenna. The module is designed with an embedded system-on-chip solution that eliminates the need for an external MCU, simplifying and reducing overall system cost. It supports 802.11b/g/n Wi-Fi protocols with a maximum data rate of up to 150Mbps in an 11n network. The module also comes with an operating voltage of 3.3V with maximum current consumption of up to 250mA. It has UART interface for programming and can operate up to a temperature range of -40°C to +85°C.