ESP32-WROOM-32U 4M 128Mbit WiFi Bluetooth Module w/ U.FL Connector

The primary difference is the antenna connector. The ESP32-WROOM-32U features an integrated U.FL (IPEX) connector for attaching an external antenna, while the ESP32-WROOM-32D has a PCB trace antenna. The U.FL version provides flexibility for using higher-gain antennas to extend wireless range or meet specific enclosure RF requirements. All other core specifications, including the dual-core ESP32 processor, 4MB flash, and wireless protocols, are identical between the two variants.

You will need a compatible U.FL to SMA (or other connector) pigtail cable. Carefully mate the cable's U.FL plug with the connector on the module, ensuring a straight, firm push until it clicks. Route the cable away from noisy digital lines and connect your chosen antenna (e.g., 2.4GHz dipole) to the other end. Ensure the antenna impedance is 50 ohms. For optimal performance, keep the pigtail as short as possible and avoid sharp bends to minimize signal loss.

This module is fully compatible with the official Espressif IoT Development Framework (ESP-IDF) for low-level control, Arduino Core for ESP32 for simplified prototyping, and MicroPython for high-level scripting. You can program it via a USB-to-serial adapter connected to its UART pins (GPIO1/TXD, GPIO3/RXD) using standard 3.3V logic levels. The module typically operates at a default baud rate of 115200 for serial communication and firmware uploads via the esptool.py utility.

While an exact deep sleep current isn't specified in the provided data, the ESP32 chip itself can achieve deep sleep currents as low as 10µA to 150µA depending on what peripherals (like RTC memory or GPIO wake-up) are kept powered. To achieve the lowest power, you must disable the Wi-Fi and Bluetooth radios and put the main CPUs to sleep. Power consumption is highly dependent on your firmware configuration, wake-up sources, and the voltage of your power supply within the 2.2V to 3.6V range.