#The 7th Lichuang Electric Competition# Intelligent control equipment based on national technology

* 1. Introduction to project functions
This project is based on the design of intelligent control equipment of N32G430C8L7 of National Technology. Its function is to be able to control equipment by voice recognition or mobile phone. Voice recognition control recognizes instructions through the voice recognition module, and then controls related equipment; mobile phone control communicates with the board through the Bluetooth module, so as to realize the control of the equipment by the mobile phone.
* 2. Introduction to the scheme
2.1 System scheme structure
The architecture of this scheme design is shown in Figure 2.1. It is mainly divided into LED light module, voice recognition module, Bluetooth module, servo, light detection module, main controller N32G430C8L7, etc. It aims to use offline voice recognition or mobile phone to control smart devices and simulate smart home system.
2.2 Hardware circuit connection design
See the specific circuit and schematic design for details.
 
* 3. Physical picture
 
* 4. Some functional modules
4.1
 Power supply
According to the manual provided by National Technology, the main controller N32G430C8L7 requires an operating voltage (VDD) of 2.4V to 3.6V, and VDD is an external power supply. Therefore, the power supply part of this design uses the USB port to supply 5V power, and then uses the voltage regulator chip AMS1117-3.3V to convert the supply voltage 5V into 3.3V voltage. SW1 is the power switch; C1 and C2 are input capacitors, which are used to filter the input power; C3 and C4 are output capacitors, which are used to suppress self-oscillation. The LED light is the power indicator. The circuit schematic diagram of the power supply part is shown in the figure.
Figure 4.1.1 Power supply circuit
4.2 LED module circuit The
LED module is composed of four LED lights (illumination light, red light, blue light, green light) and a current limiting resistor. The anode of the LED light is connected to the pull-up resistor, and the cathode is connected to IO, which is connected to PA4, PA5, PA6, and PA7 respectively. When the IO port outputs a low level, the LED is on; when the output is a high level, the LED light is off. The circuit is shown in the figure.
Figure 4.2.1 LED module circuit
4.3BOOT selection circuit, reset circuit, download debugging interface
circuit Figure 4.3.1 Download debugging circuit
4.4 The SG90 motor
servo is controlled by a pulse signal, which generally requires a 20ms time base pulse, and the high level is generally 0.5ms to 2.5ms. (As shown in Figure 4.4.1), when the pulse width changes, the servo angle will also change, and the changes of the two are proportional. Therefore, the duty cycle can be adjusted according to this relationship to change the position of the servo. This project outputs PWM signals through pins to control the rotation angle of the servo, thereby realizing the switch function of the device. The corresponding relationship between the angle and pulse width of the servo used in this design (the actual picture is shown in Figure 4.4.2) is shown in Table 4-4-1.
Figure 4.4.1 Control requirements of servo
Figure 4.4.2 Actual servo
Figure 4-4-1 Relationship between pulse width and servo rotation angle

Pulse width


0.5ms


1.0ms


1.5ms


2.0ms


2.5ms


Servo angle


0°


45°


90°


-135°


-180°

4.5 BLE transparent transmission module
HC05 module is a high-performance master-slave integrated Bluetooth serial port module that can be paired with various computers with Bluetooth functions, host PDAs, PSPs and other intelligent terminals. The module supports a very wide baud rate range: 4800~1382400, and the module is compatible with 5V or 3.3V single-chip systems, which can be easily connected to your products. It is more flexible and convenient to use.
Figure 5.1.1 HC05 Bluetooth transparent transmission module
 
1. LED pairing status output; it outputs high level when pairing is successful, and outputs low level when it is not paired. 2. KEY is used to enter AT state; high level is valid (low level is the default when floating). 3. RXD module serial port receiving pin (TTL level, cannot be directly connected to RS232 level!), can be connected to MCU's TXD4, TXD module serial port sending pin (TTL level, cannot be directly connected to RS232 level!), can be connected to MCU's RXD5, GND ground 6, VCC power supply (3.3V~5.0V)
4.6 Voice Recognition Module
This project uses SU-03T module to realize voice recognition function, first recognize the external sound, then judge the corresponding information, generate corresponding instructions, and then communicate the instructions with N32G430C8L7 MCU through serial communication, and the MCU controls the device to realize the corresponding function.
Figure 4.6.1 SU-03T
module Figure 4.6.2 SU-03T module pin diagram
 For easy use, the SU-03T expansion design circuit diagram and the circuit connected to the chip interface are shown in the figure.
Figure 4.6.3 Schematic diagram of SU-03T expansion module
Figure 4.6.4 Schematic diagram of voice recognition module
*5. Software part
The program flow chart of this project is shown in the figure:
*6. Problems encountered
Before this project, I had never soldered chips. I had only soldered switches, USB, and 0805 relatively simple components. The N32G430C8L7 chip used in this design is packaged as LQFP48. The IC pins are relatively dense. For me who have never soldered, it is a great challenge. During the soldering process, it is easy to cause the solder to stick together, and it is easy to solder the chip badly. After several solderings, I finally succeeded in soldering.
*7. Gains
Thank you very much for the opportunity to participate in this summer training camp. In this process, although the time is very tight, I have learned a lot of knowledge.
1. This project is my first time to use Jiali Chuang EDA Professional Edition. In this activity, I learned to use the professional version.
2. I have a new contact with the development project of National Technology MCU.
3. Learn the skills of soldering LQFP48 packaged chips.
4. I hope to have more opportunities to participate in Li Chuang's activities in the future.