LoRa module LoRa1262 evaluation

LoRa1262 wireless module is a LoRa module product launched by our company. Today I will do an evaluation for you, the purpose is to help you understand this wireless module as soon as possible. The LoRa1262 wireless module uses Semtech's SX1262 device, a high-precision TCXO crystal oscillator, ultra-low receiving current and sleep current, and a sensitivity of -148dBm. The built-in 64KHz crystal oscillator can wake up the microcontroller regularly under low power consumption. The antenna switch of this module is integrated and controlled inside the chip, which saves the resources of the external MCU. The compact size is matched with an output power of 22dBm (160mw), which has great advantages in IoT and battery-powered application scenarios.

The biggest feature of the LoRa module LoRa1262 is its application in the field of low power consumption. Its receiving current and sleep current have reached an industry-leading level. Perhaps I feel that my words are useless. Let's list the current comparison of LoRa module LoRa1262 and LoRa1278 as reference data.

（LoRa1262 measured receiving current）

（LoRa1262 measured sleep current）

It can be seen from the table that the receiving current of the LoRa module LoRa1262 is much lower than that of LoRa1278, but the transmitting current of LoRa1262 is higher than that of LoRa1278. This shows that while the power consumption of LoRa1262 module is lower than that of LoRa1278 wireless module, the output power of LoRa1262 is also Bigger than LoRa1278. Overall, the low power consumption and power of the LoRa1262 wireless module is better than that of the LoRa1278 wireless module.

Our LoRa1262 wireless module uses TCXO crystal oscillator. What is the difference between TCXO crystal oscillator and ordinary crystal oscillator? The function of the crystal oscillator is to make the frequency of the module more accurate. However, no matter how accurate the crystal oscillator is, there will be a certain deviation. The difference between the TCXO crystal oscillator and the ordinary crystal oscillator is that the deviation is small and the accuracy is high. The accuracy of the TCXO crystal oscillator can reach 1ppm. -+85 degrees) range is 1PPM, will automatically compensate the frequency deviation according to the ambient temperature; while the ordinary crystal oscillator has an accuracy of 10ppm, and will not automatically compensate for the frequency deviation according to the ambient temperature. But relatively speaking, the current of a high-precision crystal is a little higher than that of a low-precision crystal.

Next, we need to carry out on-site ranging of the LoRa1262 wireless module, and the test location is selected at 107 National Road, Bao'an District, Shenzhen. Since the LoRa1262 wireless module is a front-end module, it cannot transmit and receive by itself, and it can only be transmitted and received with the help of a DEMO board. So when we are testing, we need to prepare two DEMO boards, in addition to the two DEMO boards, we need to install a 425px wire antenna. As shown in the figure:

Before ranging, we need to set the same parameters of the two DEMO boards. The parameters are as follows: frequency: 441.5MHz; BW=500K; SF=12; rate>0.8K. Test result: The overpass between the Transportation Bureau of Shenzhen Baoan District and Xicheng Industrial Zone in Baoan can send and receive signals to each other, a total of 5 kilometers.