They cut the cost by removing Bluetooth, though, so ESP32-S2 might not be the right choice for some scenarios.

Since the S2 has USB OTG, I wonder whether anyone's working on porting the QMK keyboard-firmware project to it. QMK on ESP32 could make for one heck of an overpowered mechanical keyboard.

Too bad there's no Bluetooth.

USB-OTG on a small microcontroller like the ESP32S also presents significant opportunities for malicious 'anti-security' devices pretending to be other devices, while up to no good. (See 'Malduino')

With its single-core and no Bluetooth, I see the ESP32-S as more of an upgrade to the ESP8266, or 'ESP32-'lite'.

the upcoming S3 will have Bluetooth while being otherwise similar

99 cents? I guess that's for volume and possibly for the bare chip?

Does anyone know if I can get the chip in a form factor that's hand-solderable (so with castellated edges) and with a built-in antenna (rather than an ipex connector) for close to that price? That might finally get me off the ESP8266.

Yes, check AliExpress for ESP32 dev module for a board with pins.

Look at LCSC for one with castellated edges. esp32.net has info about more form factors.

At my work we have a design that uses the ESP32-WROOM-32 for the Bluetooth and CPU. It is a pretty great alternative to using Arduinos.

Oh nice, thanks, I didn't know about esp32.net!

Espressif makes 3 categories of ESP32-S2:

- IC: Just the bare chip. Costs 99c as you say.

- Module: The chip on a PCB with castellated edges and a PCB antenna (normal) or IPEX connector (the "-I" variants). These cost ~$2.

- Devkit: The module but on a PCB with 2.56mm pitch pins installed, a USB/serial converter and 3.3V power supply. These cost ~$8.

You can buy all of these at the prices I listed from the standard electronics distributors like Digikey and Mouser, you don't have to be special or anything.

I already do, I thought there was a special way to buy the modules for $1. By the way, I found some Lolin ESP32 devkits for $3.5, a great price. I got 10ish of those, as I always use them for whatever throwaway projects since the price is so good.

Holy damn. That is a solid chip and I had no idea they had a new version out! The tiny power consumption is a huge deal. I’ll be buying a couple of these to play around with.

FWIW, the S2 is also single-core.

Indeed. And I've got too used to the dual-core on the ESP32. Having the ability to pin tasks to one core for 'heavy-lifting' while running main task logic on the other, avoiding interrupts, has been a huge relief. (Though, has possibly led to some lazy coding too ;) )

haha, precisely. It's the primary reason I chose it for our company's projects -- no need for interrupts timing. From a business angle I view lazy code ~== time/money saved!