How Small Can The ESP32 Get?

At its core, the ESP32 chip is not much more than an integrated circuit, a huge mass of transistors sealed inside an epoxy resin package with some leads. Of course, most of us won’t buy discrete ESP32 chips with no support circuitry since it’s typically easier and often not that much more expensive to get them paired with development boards of some type for easy access to things like USB and GPIO. But these tiny chips need little in the way of support to get up and running as [Paul] demonstrates with this tiny ESP32 board.

The project started as a challenge for [Paul] to build the smallest ESP32 that would still function. That means carving away nearly everything normally found accompanying one of these chips. There is no charging circuitry, only one of the GPIO pins is accessible, and it even foregoes the WiFi antennas which eliminates the major reason most people would reach for this chip in the first place. But at this form factor even without wireless capabilities it still blows other chips of this stature, like the ATtiny series, out of the water.

Even though [Paul] built it as a challenge, it goes a long way to demonstrate what’s really needed to get one of these chips up and running properly. And plenty of projects don’t need a ton of I/O or Wi-Fi either, so presuming these individual chips can be found cheaply and boards produced for various projects its an excellent way to minimize size and perhaps even power requirements. You can make these boards even smaller than a USB-A connector if you want to take this process even further, too.

22 thoughts on “How Small Can The ESP32 Get?

    1. I’ve started using the ESP32-WROOM-32U modules for most of my projects. They don’t have a PCB antenna, so they are a bit smaller than ESP32-WROOM-32D (and I don’t need to add a keepout area on the PCB), but if I need WiFi I can just attach an external antenna to the IPEX connector.

  1. How hot does this get? I get the computing power is insane, but compared to an ATTiny, it’s a power hungry beast. Running this at full tilt (240 MHz), no WiFi, I would still expect it to overheat. Maybe immersion liquid cooling is the way to go here? :D

  2. You can get even smidgen smaller if you use the pico-1 SiP variant, which embedds the 40 MHz crystal oscillator along the flash and the psram.
    They had this variant of the original esp32 for a while, but they recently added it also for the esp32-s3 flagship with options of 8MB flash paired with either 2MB quad psram or 8MB octal psram.
    The first is already available normally, the latter seems to be in the late stages of sampling status (you can buy them on espressifs official aliexpress store).

  3. the esp chips are soo usefull bexound Wifi and BT and the ceiling is not reached yet.
    just recently I demonstrated running Linux on ESp32S3 on Stream. I suspect we are just on the edge of a new class of super low power sbc..cutting all the overkill.

  4. Other than the obvious WiFi/BT feature, something else the ESP32 has going for it is a single channel CAN controller. There aren’t many options as cheap as the ESP32 that has that capability.

  5. That’s what makes me genuinely sad these days: We have highly developed technology, but bad manners. Technology like this should be treaded with same respect as early CMOS ICs from the 1970s. They deserve high-quality packaging (say DIP/DIL or LCC/PLCC form factor, gold-plated contacts etc) with mechanical stability and the use of sockets. And RF shielding. The fact that we’re touching such high technology with our unwashed, fatty, plump fingers is such a sacrilege. In 21th century, we should act much more mature and respectful here. What would the gentlemen of 19th century say, if they saw us? We’re interacting with things akin to cavemen would with fine mechanics. No, worse, actually. Real cavemen had fine motorics skills and excellent vision. But that’s just my opinion, of course. Or is it?

  6. What would be really cool would be to bring out at least 8 GPIO pins. This would make this perfect to implement a drone brain. A single GPIO pin is not quite enough to effectively run a drone.

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