circuit diagram of ultrasonic distance measurement sensor

Ultrasonic distance measuring circuit diagram: Type 4Y2 distance measuring alarm control special integrated circuit, which can be used to assemble distance measuring alarm control electronic products. It uses the principle of ultrasonic distance measurement to detect obstacles in front of the ultrasonic transducer sensor, it emit different alarm sounds according to the distance of the obstacles, and provide different control signals to the external circuit through 4 control lines. This integrated circuit already contains most of the units required by the rangefinder, only a few cheap resistors and capacitors, a 455kHz piezoelectric ceramic filter used on a radio, a pair of 40kHz ultrasonic probes, and a MC4069UBE or LM324. Can be assembled into a high-performance ranging alarm controller.

This integrated circuit of ultrasonic distance sensor can be used for car reversing alarms, such as automatic doorbells, automatic water pipes, mobile phone washing and dryers, automatic street lamp control, detection of materials on various feeding devices, water tower water level control, etc.

This integrated circuit adopts DIP 16-pin plastic package, and the meaning of each leg is as follows:

XT1, external 455kHz clock signal input, piezoelectric ceramic oscillator input terminal, which can be connected to an external 455kHz high-Q piezoelectric ceramic oscillator.

D4: Control output 4, which means there is an object within 1 meter.

D3: Control output 3, which means there is an object within 0.5 meters.

D2: Control output 3, indicating that there is an object within 0.25 meters.

D1: Control output terminal 3, indicating that there is an object within 0.125 meters.

D0: High-level output terminal, no need for it.

BP: The horn driving electrode of ultrasonic liquid level sensor, which is statically low, outputs a 2500 Hz pulse when driving. The smaller the sound pitch, the closer the object is.

DULB: Double the electrodes to double all distances.

LED: Mode selection terminal, this pin should be connected to high level.

BPN: The speaker drive electrode is complementary to BP, and the static level is low.

VDD: power supply, 3~5V DC power supply.

CS: Ultrasonic transmitter drives the electrodes, which are usually in a high-impedance state. When it is driving, they output ten times per second, and each time they send out 8 pulses of 40kHz.

CSN: Complementary electrode of CN, it is usually low level.

IN: Ultrasonic receiver input terminal, it is active at high level.

GND: Ground.

XT2: The output electrode of the piezoelectric ceramic oscillator. XT1 forms a low-power inverter. The piezoelectric ceramic filter should be a product with a high Q value, otherwise it is not easy to vibrate.

The attached figure is the simplest experimental circuit, which uses an external oscillator. According to different settings, this circuit has the following specific functions:

Distance alarm circuit

BP, BPN push-pull output, it can directly drive the buzzer, the sound varies according to the distance, there are four sounds (from slow, two beeps, three beeps, to rapid and fast); the sound output can be used for car reversing alarm , doorbell, warning alarm, subway safety line reminder, etc.

Distance control circuit

D0 to D4 are five level output terminals corresponding to different distances, which can be used to drive light-emitting diodes, and the low level is effective; the distance between the five alarm points is 0 to 1.2 meters, with an interval of 0.3 meters. Its output can be directly controlled, such as automatic faucet, automatic feeding machine, automatic door, material counting on conveyor belt, etc.