ESP32-WROOM-32D / ESP32-WROOM-32U WiFi & Bluetooth Modules Deliver Better RF Performance

ESP-WROOM-32 is likely the most popular ESP32 WiFi + Bluetooth module on the market, but a few months ago, Espressif Systems unveiled two variants named ESP32-WROOM-32D / ESP32-WROOM-32U, which are based on ESP32-D0WD (5x5mm package) instead of ESP32-D0WDQ6 (6x6mm package), and are said to offer better RF performance

ESP32-WROOM-32D is the most similar to ESP-WROOM-32 since it also comes with a PCB antenna, while ESP32-WROOM-32U is much smaller as it relies on an external WiFi/Bluetooth antenna via a u.FL connector. Both new modules are pin-to-pin compatible with ESP-WROOM-32

Key features:

  • CPU – Espressif ESP32-D0WD dual core Tensilica processor
  • Storage – 32Mbit SPI flash
  • Crystal – 40 MHz
  • Connectivity – Wi-Fi 802.11 b/g/n up to 150 Mbps, Bluetooth 4.2 LE
  • I/Os – 38- catellagated pin with I/Os + GND plane
  • Antenna
    • ESP32-WROOM-32D – on-board antenna
    • ESP32-WROOM-32U – u.FL connector for external IPEX antenna
  • Dimensions
    • ESP32-WROOM-32D – 18 x 25.5 x 3.1 mm
    • ESP32-WROOM-32U – 18 x 19.2 x 3.2 mm

There looks to be some confusion about the product names, as Espressif Systems names the modules ESP32-WROOM-32D and ESP32-WROOM-32U on the official product page (with datasheet, TRM, etc…), but whoever made the module pictured above, named the former ESP-WROOM-32D.

The modules were first spotted on by Reddit users three months ago, but I’ve just found out about it through Electrodragon which sells the original ESP-WROOM-32 and ESP-WROOM-32D modules for 3.06 Euros, and the ESP32-WROOM-32U module for 3.14 Euros. The D model will however only start shipping around the end of March.

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itchy n scratchy
itchy n scratchy

Im wondering if the ufl version is any better than the usual wifi equipment when it comes to range…

Jon Smirl

You can make an ESP32 PCB with an external PA/LNA chip on it and go right up to the FCC power limit. But doing that eats up a lot of power – probably 5x the normal ESP draw – and that limits the market. Add on a high quality antenna and you can get your range up to a mile or more. It is just a function of how much money you want to spend and how big the antenna is.

A TI CC2591 should work. About $3.50


@Jon Smirl
I remember a few YouTube videos on WiFi Range of the older ESP8266 pcb’s by ‘that Swiss guy’ stating he got a mile or more. Problem was, he went to such lengths to maximise the range, like disable the normal return path, and only send ‘pings’, it did not test a real-world practical link where people want a usable bandwidth for sending volumes of data. I think he may have also used a very high gain antenna with narrow beamwidth, which highly limits use cases.

Pycom claims 1Km range for their ESM32 modules, but only under ‘special conditions’ and only between like ESM32 modules, which also rather limits use cases. They also state their ESM32 modules have a best transfer rate of 16Mbit/s – I assume in optimum conditions of short range only. That is just over 10% of the 150 Mbps rate on the Expressif ESM32 datasheet.

Do you know any links to range tests, using maybe high gain (6-12dBi) omni-directional antenna for the client end, that measure ESP32 client range versus useful TCP/IP transfer rates ?