Student, first IoT project: a small weather station for our hostel that sends temperature, humidity and pressure to Hermetry every 5 minutes. I went to order an ESP32 and found ESP32-WROOM-32, WROOM-32E, WROOM-32UE, WROVER-E, MINI-1… and N4, N8, N16R8 at the end. What does WROOM even mean? I searched and found three different answers. Which one should a beginner pick for something like this?
I always assumed WROOM was “Wireless ROOM” or something. Never checked.
WROVER has extra PSRAM on the module, WROOM doesn’t. For a weather station you won’t need PSRAM.
ok so WROOM then. But E or UE?
I use a DevKitC board with a WROOM-32E on it for everything at home, plug in USB and go.
Depends where the box goes. If it’s a metal or IP65 enclosure on a wall, take the UE and an external antenna. The PCB antenna on the E is fine on a desk and poor inside metal.
+1 to Grace. We lost a week on a site job because of a PCB antenna inside a steel cabinet.
As far as I know Espressif has never officially said what WROOM stands for, so don’t trust the three answers you found. In practice it’s their name for a module family: the chip, flash, crystal and antenna on one shielded board you can solder on.
The suffixes:
- WROOM = module without PSRAM, WROVER = with PSRAM, MINI = smaller footprint.
- -E = ESP32 chip revision 3 (fixes several early silicon bugs). Buy E, not the old plain -32.
- U in the name (32UE) = u.FL connector for an external antenna instead of the PCB antenna.
- N4/N8/N16 = MB of flash, R8 = MB of PSRAM.
For your station: a DevKitC board with a WROOM-32E N4 to start, like Aisha has. 4 MB flash leaves room for two OTA partitions if you ever want to update it over the air. If the box ends up outdoors in a metal housing, switch to the 32UE as Grace said. Wake every 5 minutes, send one HTTPS POST to Hermetry’s device API, sleep: that keeps the board cool too, so it doesn’t heat the sensor.
Ordered a DevKitC with WROOM-32E N4. The box will be a plastic one under the roof edge, so PCB antenna it is. Thanks Brian, and everyone, the U and E part was what confused me most.
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