# Adafruit CH552 QT Py - 8051 Dev Board with STEMMA QT

**Type:** Product page · **SKU:** ADA5960 · **Brand:** [Adafruit](https://core-electronics.com.au/brands/adafruit-australia)
**Page:** https://core-electronics.com.au/adafruit-ch552-qt-py-8051-dev-board-with-stemma-qt.html ([markdown](https://core-electronics.com.au/adafruit-ch552-qt-py-8051-dev-board-with-stemma-qt.html.md))

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...

## Pricing

- **Price:** $8.85 (inc GST) — $8.05 AUD, exc GST
- **Quantity discounts:** 10+ $7.80 (exc GST) · 50+ $7.65 (exc GST)

## Availability & dispatch

- Available with a lead time — expect dispatch between Aug 31 and Sep 03.

## Description

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](https://core-electronics.com.au/adafruit-qt-py-s3-with-2mb-psram-wifi-dev-board-with-stemma-qt.html), but there's lots of folks interested in the [CH552](https://www.wch-ic.com/products/CH552.html) and given the smol size, it is a nice matchup for a smol board.

[The CH552 is an 'enhanced' E8051 core microcontroller](https://www.wch-ic.com/products/CH552.html), 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, Adafruit have wrapped it up in a QT Py format. The pinout and shape is [Seeed Xiao](https://core-electronics.com.au/seeeduino-xiao-pre-soldered.html) compatible, with castellated pads so you can solder it flat to a PCB. It comes with Adafruit's favorite connector - the STEMMA QT, a chainable I2C port that can be used with [any of Adafruit's STEMMA QT sensors and accessories](https://core-electronics.com.au/#). They 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'](https://github.com/DeqingSun/ch55xduino) Adafruit 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'](https://hackaday.com/2023/03/03/all-the-usb-you-can-do-with-a-ch552/)

- Same size, form-factor, and pin-out as Seeed Xiao
- **USB Type C connector** - [If you have only Micro B cables, this adapter will come in handy](https://core-electronics.com.au/micro-b-usb-to-usb-c-adapter.html)!
- **CH552 8-bit 8051** microcontroller core with 3.3V power/logic. Internal 16 MHz oscillator.
- Native USB
- **Built in RGB NeoPixel LED**
- **10 GPIO pins:**
    - **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
- 3.3V regulator with [**600mA peak output**](https://core-electronics.com.au/attachments/localcontent/AP2112_75527108c38.pdf)
- **Reset switch and bootloader** for starting your project code over or entering USB ROM bootloader mode
- **Really really small**

## Technical Details 

![RoHS 2 2011 65 EU Compliant](https://core-electronics.com.au/attachments/localcontent/RoHS2_2011_65_EU_7356c5574c.svg)![RoHS 2 2015 863 EU Compliant](https://core-electronics.com.au/attachments/localcontent/RoHS2_2015_863_EU_86773f57f9.svg)

## Images

- [Product image 1](https://core-electronics.com.au/media/catalog/product/A/D/ADA5960-1.jpg)