Ultrasonic sensors
60.00 ฿
Ultrasonic sensors overcome many of the weaknesses of IR sensors - they provide distance measurement regardless of color and lighting of obstacles.
They also provide lower minimum distances and wider angles of detection to gaurantee that obstacles are not missed by a narrow sensor beam.
THIS particular model is an upgrade from the lower precision HC-SRO4. This has 5 pins and can be used in 1-pin trigger/echo or 2-pin.
Specifications
Check the datasheet for details and graphs but these are the highlights:
- Trigger Pin Format:
10 uS digital
pulse - Sound Frequency:
40 kHz
- Echo Pin Output:
0-Vcc
- Echo Pin Format: output is
DIGITAL
and directly proportional with range. See our conversion formula above. - Measurement Range:
2cm to ~4.5m
- Measurement Resolution:
0.3cm
- Measurement Angle: up to
15 deg
- Measurement Rate:
40 Hz
- Supply Voltage:
4.5V to 5.5V
- Supply Current:
10 to 40mA
- Connector: standard
5-pin male
connector which can plug directly into breadboards.
Measurement Procedure & Formula
Distance measurements can be made with microcontrollers in a straightforward manner:
You can find an Arduino Library with code here: http://forum.arduino.cc/index.php?topic=106043.0
- Send a 10 uS wide pulse to the sensor on the Trigger Pin. The sensor will automatically send out a 40 kHz wave.
- Begin monitoring the output from the Echo Pin and
- When the Echo Pin goes high, begin a timer.
-
When the Echo Pin goes low, record the elapsed time from the timer and use the following conversion formula:
Distance (in cm) = (elapsed time * sound velocity (340 m/s)) / 100 / 2
Note: we divide distance by 2 because the sensor returns the round trip time, which doubles the distance measurement.