Barebones ESP32-WROVER

[rdagger]

I see that Mouser has the ESP32-WROVER for around $4. Assuming you don't need USB, would it be correct to conclude that the only other components required are a 10K resistor to pull up the enable pin and a couple of decoupling caps?

[OutoftheBOTS_]

U will also need a power regulator (LDO)

[rdagger]

U will also need a power regulator (LDO)

Any recommendations for efficient 5V to 3.3V (preferably surface mount)?

Has anyone determined the minimum current requirements? I know the Wi-Fi can be relatively demanding.

[OutoftheBOTS_]

The Wrover datasheet has a recommended peripheral circuits see below

wrover.JPG (123.32 KiB) Viewed 3969 times

The ESP32 datasheet has the radio power consumption listed too see below

esp32.JPG (96.68 KiB) Viewed 3969 times

I did plan to make a low power ESP32 using this http://www.ti.com/product/tps63000/description buck/boost converter from TI that is designed for running efficiently a 3.3v MCUs off a 1 cell Lipo with input range of 1.8v -0 5.5v. TI do also make some even smaller BGA packages as well but they were getting beyond my soldering.

[rdagger]

Thanks that's very helpful.

The current specs are typical, but it has been my observations that there is a current spike when the radio is turned on. Often the spike is enough to brown out when using an inadequate power supply.

[OutoftheBOTS_]

Yes do note the recommended caps on the wrover peripheral schematics. I have used boards where they have reduced the caps and had troubles with unstable behavior, this is the reason that I started to build my own boards.

I have just mainly used the AMS1117 LDO as it is a tank that can supply way more than anything that I need but others haven't liked it due to high quendesint current during deep sleep mode.

[rdagger]

Are you using ESP32-WROVER or ESP32-WROVER-B?
Is the B version the same except more PSRAM and smaller chip size?

[OutoftheBOTS_]

I am using the original Wrover not sure about what's different with the Wrover-b

edit : it looks like the Wrover-B has 8MB psRAM instead of 4MB psRAM not sure what other differences there is

edit : it also uses the new version of the ESP32 chip ESP32‑D0WD