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102 TRƯỜNG ĐẠI HỌC SƯ PHẠM KỸ THUẬT - ĐẠI HỌC ĐÀ NẴNG

B. LoRa E32-433T20D

Fig. 3. LoRa E32-433T20D
The E32-433T20D module utilizes Semtech's Fig. 4. LoRa transmission scenarios [7]
SX1278 chip, enabling transparent communication in • Transparent transmission: This can be
the 410-441MHz frequency band through LoRa considered the default mode, where the device can
spread spectrum technology. LoRa spread spectrum engage in two-way communication with all devices
technology offers numerous advantages, including sharing the same address and channel configuration.
extended communication range, robust resistance to
interference, and high-security levels. Additionally, • Fixed transmission: This communication can
the module incorporates data encryption and specify addresses and channels for two-way
compression features. While the module transmits communication.
data wirelessly, the data compression function • Fixed transmission broadcast: Information can
minimizes transmission time, lowers the chances of only be transmitted to other devices with the same
interference, and enhances both reliability and address and channel.
transmission efficiency. • Fixed transmission monitoring: Can only receive
The E32-433T20D integrates the SPI interface information from other devices with the same address
conversion of the SX1278 to UART, simplifying and channel.
communication and usage. You can easily configure C. Distance sensor
the address, speed, and transmission power by Ultrasonic distance measuring sensors are
connecting it to the company's software. E32- designed to measure distances remotely. The device
433T20D strictly adheres to FCC, CE, and CCC comprises a transmitter and a transceiver capable of
regulations, meeting various RF-related certifications emitting and receiving ultrasonic waves. The
and export requirements [6]
transmitter emits sound frequencies above 18kHz into
Table II. Technical specifications of lora the air at a velocity of 344m/s (at 20°C), and the
E32-433T20D receiver captures the sound waves reflected from the
No. Parameters Value object. The distance to the object is calculated by
measuring the time it takes for the ultrasonic wave to
1 Long distance anti-interference Yes
travel from the transmitter to the object and back [8].
2 Maximum transmission distance 3000m
To calculate the distance from the ultrasonic
3 Maximum transmit power 100mW
sensor to an object, we rely on the relationship
4 ISM band 433MHz
between velocity and time:
5 Data transmission rate 0,3k~19,2kbps
S = vt ;t = T / 2  S = vT / 2 (1)
6 Power supply 2,3-5,5V
7 Operating temperature -40~+85°C In which, v is the speed of sound in the air (≈
340m/s), t is the time for sound to travel to the

object, and T is the time for sound to travel to the
object and back to the sensor.

ISBN: 978-604-80-9122-4