gCore - short for Gadget Core - is a high-performance ESP32 development board I designed for my open source tCam thermal imaging camera and to be a platform for other portable devices.

It has the features and performance I found missing on other dev boards. If you've ever found yourself kludging a bunch of breakout boards together or wishing for things like better graphics performance or soft power control then gCore is for you.

1. Fast graphics - 3.5" ILI9488-based 480x320 pixel cap touch LCD driven by an 80 MHz SPI interface through a SPI-to-parallel interface.
2. Lots of memory - ESP32 WROVER E with 16 MB Flash and 8 MB PSRAM.
3. Fast File IO - Micro-SD slot with 4-bit SD-mode data path
4. PMIC/RTC Co-processor (see below).
5. Portable power - Standard JST connected LiPo battery backed with a full power-path 500 mA or 1 A charging circuit. Unlike a lot of cheap dev boards, the battery isn't in parallel with the load and charging is managed separately from powering the system.
6. USB-C charge/programming port (serial interface).
7. Power switched raw battery and regulated 3.3V supplies for external circuits. There's even a low current always on 3.3V supply so parts of your circuit can always run or be used to power up the entire system.
8. GPIO headers and Qwiic I2C connector for easy expansion.

The ultra-low power EFM8 co-processor and supporting circuitry provide a bunch of cool capabilities.

• Battery backed Real Time Clock (RTC) with alarm
• Soft power control - Switch power on from a variety of sources including a power button, RTC Alarm, or even when the charging starts and/or completes. Switch power off from your code running on the ESP32, using the power button, even if the ESP32 is crashed, or automatically when a critically low battery level is detected. You can even use the power button as a software available button (short press) and power off button (long press) at the same time.
• Backlight brightness control
• Monitor charge status, USB and battery voltages, USB and load (board) currents. Compute the charge current easily (USB - load current).
• Charge indicator LED - pulses while charging, solid when charge complete, blinking for fault.
• 4096 bytes of battery backed NVRAM to save data without worry of flash degradation or losing configuration when the ESP32 is erased (there's also a 1024 byte Flash backing store available too).

What can you do with gCore?

How about a lighting system remote control that turns on automatically when you pick it up?

Or a video game emulator with 60 FPS graphics

Explore your backyard using a remote controlled tank with video streaming

Do all the maths in hex or decimal with a programmer's calculator

Stream from thousands of internet radio stations from around the world.

Plenty of software support and demo code

Like you, perhaps, I've struggled trying to figure out how to control various boards over the years so I committed to providing great software support for gCore.

gCore code can be created using Arduino, the Espressif IDF or MicroPython. There's even a Desktop app that runs on Linux, Mac or Windows that allows you to load the various demos and gCore applications I've written without having to compile anything.

There are Arduino libraries for accessing the co-processor and a port of TFT_eSPI that enables blazing fast graphics (see the video). In addition there are lots of Arduino and Espressif IDF demos and examples showing how to use all features of the board. I am a heavy user of the LVGL graphics/GUI library and there are several demos including drivers for the LCD, touchscreen and gCore hardware. The MicroPython port also has support for LVGL.

3D Printed Enclosure designs

Housing our creations is sometimes the most difficult part. I designed a simple enclosure using OpenSCAD that can be printed on most FDM printers. The design is in the repo so you can make changes to fit your own needs.

All open source

I know it's helpful sometimes to thoroughly understand the system. The complete hardware design, firmware and software is available in the main and supporting github repositories and directly downloadable from my website.

Links

• Main github repository - Documentation, Arduino libraries with demos and examples and design files.
• My website - Links and file downloads in case you don't want the whole repo.
• TFT_eSPI port - TFT_eSPI configured for gCore with 80 MHz SPI
• MicroPython port - LVGL binding for MicroPython
• tCam - A complete, full-feature, thermal imaging camera using gCore.
• gcore_life - LVGL and gCore integration in an Espressif IDF project.
• gcore_tank - Remote control tank with video streaming.
• Galagino - Galaga emulator running on gCore with audio.
• gcore_lv_port_esp32 - LVGL v7 with gCore drivers.
• gcore_lv_music_demo - The LVGL v9 music demo.

Yeah but it's expensive!

First, congrats if you made it all the way down here! Yeah, I know it's more than some other boards. That's not because I'm going to get rich from this. It's because gCore does things the other boards can't. And those capabilities take extra parts which add to the cost. Plus it's made in relatively low volumes. If a less expensive board meets your needs then I say buy it. But if you see how the features in this board are useful and make more capable devices, then for a delta price that's probably less than a night out on the town, you can have a very cool board to build your awesome project with. And I look forward to seeing what people make. Cheers! Dan