The first ESP32 device I’ve bought is the M5Stack Core, which I shorten to M5Core. Here’s the official product page. The “5” is supposed to mean “5 centimeters”, which should be the dimension of the device (it is square) but in reality that’s the dimension of the circuit boards inside. The module itself measures 54 x 54 mm.

It’s pretty and self-contained, with a display, buttons and a battery. The kind of device you would totally be able to play with while on the train. Or on the plane. Assuming you’re not afraid that some luddite will mistake you for a bomb-maker :

To see many examples of what it can do, head over to this site.

It’s tiny but packed like an egg. Here’s what you’ll see if you separate the top and bottom halves of the device :

The ESP32 MCU is located under an RF shield, onto which a very helpful sticker indicates the pinout of the internal expansion connector. There are similar stickers under the bottom half of the casing for the I/O connectors coming out of each side. Me and my OCD like it.

They really threw a lot of useful stuff inside this tiny module. There’s even a LiPo battery underneath the bottom circuit board, along with magnets so you can stick the device to anything magnets will stick to. Here’s some of the key specifications straight from the manufacturer :

·        ESP32 : 240 MHz dual-core Tensilica LX6 microcontroller with 520 KB SRAM, WiFi b/g/n and dual-mode Bluetooth.

·        320 x 240 pixels color LCD with an ILI9341 controller.

·        SPI interface, which I suspect is shared with the display.

·        I2C interface, also brough to a “Grove” compatible connector.

·        Two UART’s.

·        IIS.

·        SD Card socket.

·        Internal loudspeaker (1 W)

·        Single cell LiPo battery (3.7 V / 150 mAh)

In this section, I’ll be documenting this module and how to use it.