ARM microcontroller ultrasonic monitoring early warning system circuit design

With the development of informationization, intelligence, networked development, embedded system technology has won a wide development space, and the industrial control field also has a huge change, with 32-bit high-end processors for real-time embedded hardware and software technologies. Will be applied to the various corners of industrial control. The embedded controller has many advantages such as small volume, high reliability, strong function, flexible and convenient, and its application has been deeply invested in various fields such as industrial, agriculture, education, national defense, scientific research, and daily lives. Product update, accelerated automation process, increase productivity, etc. have played an extremely important role. Design of obstacle distance detection circuit In this system, the ultrasonic ranging circuit is designed by the PIC16C57 of Microchip, and the selected ultrasonic sensor is T / R40-16 piezoelectric ceramic sensor. In the work, the master PIC16C57 transmits signals to transmit the ultrasonic transducer of the transmitting end, which transmits an ultrasonic wave in the form of a pulse. When the ultrasonic receiver receives the echo signal, it is transmitted back to the master. In the middle, the timer in the master starts timing when the pulse signal begins, and the time is stopped when the echo signal is received. The time interval is multiplied by a sound speed to obtain twice the distance value. Thereby, the distance of the obstacle to the launch point is calculated. Its circuit diagram is shown in Figure 2. The distance value is serially output by 10 foots of PIC16C57, and is connected to the serial port of ARM after the MAX232 chip. The chip MAX232 is an interface circuit designed for the RS232 standard serial port, which completes the conversion of TTL levels and RS232 levels. Sound and light alarm circuit design This system requires three-level alarms on hazardous conditions based on the critical value of obstacle distances affecting the stability of the loader. When it is in a low hazardous situation, only the indicator light is lit, reminding the driver to pay attention; when the danger level increases, the indicator light is lit, while accompanying the soothing beep, reminding the driver to take measures; When the danger level, the indicator light is lit, and the beep is soothing to be urgent, reminding the driver to brake. In design, P2.20 (GPIOA4) of LPC2290 is used, respectively, the green LED, P2.21 (GPIOA5) drives yellow LED, P2.22 (GPIOA6) drives red LED, P2.23 (GPIOA7) drive buzzer. The designated alarm circuit is shown in Figure 3. Through experimental verification, the system has completed the required functional requirements, the measured value is 9.99m, and the error is ≤0.01m. Installation is very convenient for easy use. However, the system also has a deficiencies that use the ultrasonic sensor to detect the front pavement information of the vehicle, if it is a protruding obstacle energy to detect, but the current is not detected when the pit is pit, so it is presented in further study. Be Source: Wiku Electronic Market Network