What a cutie pie! Or is it… a QT Py? This diminutive dev board comes with a throwback processor – an 8-bit 8051! This tiny core is a big change from something like the the ESP32-S3 QT Py with two 240MHz 32-bit cores, but there’s lots of folks interested in the CH552 and given the smol size, it is a nice matchup for a smol board.
The CH552 is an ‘enhanced’ E8051 core microcontroller, compatible with MCS51 instruction set but with 8~15 times faster instruction execution speed. You can run this core at 16MHz and 3.3V logic, and it’s gotbuilt-in 16K program FLASH memory and, 256-byte internal RAM plus 1K-byte internal xRAM (xRAM supports DMA. It’s also got some cute tricks up it’s sleeve, like 4 built-in ADC channels, capacitive touch support, 3 timers / PWM channels, hardware UART, SPI, and a full-speed USB device controller. The last one means it can act like a native USB device such as CDC serial or mouse/keyboard HID.
If you’re interested in playing with this chip, we’ve wrapped it up in a QT Py format. The pinout and shape is Seeed Xiao compatible, with castellated pads so you can solder it flat to a PCB. It comes with our favorite connector – the STEMMA QT, a chainable I2C port that can be used with any of our STEMMA QT sensors and accessories. We also added an RGB NeoPixel and both a reset button and ‘bootloader enter’ button.
Please note! This is a minimal 8-bit microcontroller, and it definitely does not run CircuitPython or Micropython. It also doesn’t really run Arduino. There’s an Arduino ‘board support package’ we recommend, but the compiler is for C not C++, which means you cannot use any Arduino libraries. It’s very very bare-bones and for hacking/experimenting with this ’40 cent chip’
A2 pin is the same as MOSI pin (it’s the hardware SPI port and one of only 4 ADC pns)https://github.com/DeqingSun/ch55xduino4 x 8-bit analog inputs on A0, A1, A2, and A3
3 x PWM outputs
I2C port with STEMMA QT plug-n-play connector
Hardware UART
Hardware SPI
4 x Capacitive Touch with no additional components required, on A0-A3 pins
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Stop breadboarding and soldering – start making immediately! Adafruit’s Circuit Playground is jam-packed with LEDs, sensors, buttons, alligator clip pads and more. Build projects with Circuit Playground in a few minutes with the drag-and-drop MakeCode programming site, learn computer science using the CS Discoveries class on code.org, jump into CircuitPython to learn Python and hardware together, TinyGO, or even use the Arduino IDE. Circuit Playground Express is the newest and best Circuit Playground board, with support for CircuitPython, MakeCode, and Arduino. It has a powerful processor, 10 NeoPixels, mini speaker, InfraRed receive and transmit, two buttons, a switch, 14 alligator clip pads, and lots of sensors: capacitive touch, IR proximity, temperature, light, motion and sound. A whole wide world of electronics and coding is waiting for you, and it fits in the palm of your hand.
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