Adafruit just announced Adafruit CH552 QT Py and this board ranks in the top part of my weird tech list. The MCU used in this is a WinChipHead (WCH) CH552 has an E8051 Core. with 16 kilobytes of flash memory but only about 1.25 kilobytes of RAM, and the most weird thing about this it has a built-in USB physical interface (PHY).
An 8051 with USB! surprising but true. The QT Py follows the tiny Seeed Studio Xiao form factor, measuring just 20 by 17.5 millimeters. It features a microcontroller with a USB-C interface for programming and an RGB NeoPixel LED for visual feedback. With 10 GPIO pins and castellated edges, it offers flexibility for soldering header pins or direct attachment to a circuit board.
The CH552 has specific programming requirements and doesn’t support MicroPython or CircuitPython. If using the Arduino IDE, you’ll need the ch55xduino board support package, which has a limited-feature compiler. Not all Arduino libraries are compatible, so testing example code is advisable. Check out Toby Chui’s project for an example using the CH552: a hotplate controlled by the CH552 to regulate the heating profile.
Adafruit CH552 Specifications:
- Compact, Seeed Xiao-compatible design
- USB Type-C connector with Micro B adapter compatibility
- CH552 8-bit 8051 microcontroller core, 3.3V logic, and 16 MHz internal oscillator
- Native USB support
- Integrated RGB NeoPixel LED
- Versatile GPIO layout:
- A2 pin serves as MOSI for hardware SPI and one of only 4 ADC pins
- 4 x 8-bit analog inputs (A0-A3)
- 3 x PWM outputs
- I2C port with STEMMA QT plug-n-play connector
- Hardware UART and SPI
- 4 x Capacitive Touch inputs on A0-A3 pins, no extra components needed
- 3.3V regulator with 600mA peak output
- Reset switch and bootloader for easy code restart or USB ROM bootloader mode entry
Adafruit is now offering the CH552 8051 QT Py at an enticing price of $4.95. This adorable board is readily available, inviting you to delve into its distinctive features and capabilities.