Voice tracking car

1. Schematic diagram analysis of

the minimum system of the STM32F103C8T6 microcontroller. The external high-speed crystal oscillator uses 8MHZ to provide the system clock, and is equipped with a 32.768KHZ low-speed clock and a button battery to provide a reference and power-off retention for the RTC clock;

2. The motor driver chip is L298N. L298N is a dedicated driver chip for dual full-bridge stepper motors. It contains a 4-channel logic drive circuit inside. It is a dedicated driver for two-phase and four-phase stepper motors. It can drive two two-phase or one four-phase stepper motor at the same time. It contains two H-bridge high-voltage, high-current dual full-bridge drivers, receives standard TTL logic level signals, can drive 36V, 2A or less stepper motors, and can directly adjust the output voltage through the power supply; this chip can directly provide analog timing signals from the I/O port of the microcontroller. There are two enable inputs that can control the operation and cutoff of the two H bridges respectively. The emitter of the lower transistor of each bridge is connected, and a detection resistor is connected to the outside. Another logic power input enables the logic circuit to operate at a lower voltage.
The control logic is as follows
3. GY-25 is a low-cost tilt module. The operating voltage is DC +3V~ +5V, and the module has low power consumption and small size. Its working principle is to use the gyroscope and acceleration sensor through a data fusion algorithm to finally obtain direct angle data. The module's serial port baud rate is 9600bps and 115200bps, and there are two output modes: continuous output and inquiry output, which can adapt to different working environments.
4. VC-02-CN offline voice module minimum system, integrated MIC and 2W8Ω speaker.
5. The USB to serial port circuit adopts the CH340C interface chip of WCH (Nanjing Qinheng). The chip has a built-in crystal oscillator, which can save the crystal oscillator circuit and save BOM cost.
2. Analysis of the functional part
  
3. Actual picture