STC Small Tool Development Board

This project is an entry for the STC Microcontroller Innovation Competition. It mainly includes a microcontroller core circuit, a 3.3V DC-DC power supply circuit, LED and WS2812 circuits, a temperature and humidity sensor, a 6-axis attitude sensor, a 0.96-inch OLED display circuit, a button circuit, a Type-C interface circuit, and a CAN circuit.
The microcontroller core circuit
is designed based on the STC32G series datasheet, using an internal crystal oscillator and hardware USB download
. The 3.3V DC-DC power supply circuit
uses the SY8088AAC, a low-noise DC-DC chip with a 1.5MHz switching frequency. According to the datasheet, it can provide a maximum current of 1A. However, this project does not require such a large current; it is only for testing the chip. The
LED and WS2812 circuits
are unremarkable. The
temperature and humidity sensor
is a Zhongke Yinhexin GXHTC3 PIN-to-PIN compatible with Sensirui SHTC3, and is driven by hardware IIC in this project. To prevent other heat sources from affecting the measurement results, this component is intentionally separated from other components in the PCB design to minimize heat transfer.
The 6-axis attitude sensor
, the seemingly ordinary QMI8658C, is really difficult to solder. On this board, the readings are consistently unstable with huge fluctuations, I don't know if it's a soldering or chip issue. Do you have any recommendations for a 6-axis gyroscope with a better package and easier soldering?
The 0.96-inch OLED display circuitry
is from Zhongjingyuan, a 0.96-inch OLED 128*64 display screen, with an SSD1315 and IIC driver.
The button circuit
uses silent buttons, making no clicking sound when pressed, which I really appreciate.
The Type-C interface circuit
features a 16-pin Type-C port with ESD protection, providing some electrostatic discharge protection.
The isolated CAN communication circuit
uses a CA-IS3052G and B0505S-1WR3 to form an isolation circuit, achieving a maximum communication rate of 1Mbps (tested). This effectively prevents chip damage caused by potential differences. According to the chip datasheet, the CA-IS3052G has an isolation capability of 5000Vrms, and the B0505S-1WR3 has an isolation capability of 3000V. With the additional PESD1CAN, there should be no problem in general application scenarios. (PS: The B0505 ​​polarity was incorrectly marked on the prototype board; this has now been corrected.)
The attached program uses STC32G library functions to demonstrate most of the functions.