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In the following articles in the "Journey to Obtaining Technical Standards Conformity Certification" series, I introduced the process of obtaining a technical standards conformity certification (hereinafter referred to as "Technical Conformity").
The road to technical standard conformity certification Episode 1 "Let's get technical standards"
The Road to Technical Regulations Conformity Certification Episode 2 "Preparing Documents"
The Road to Acquiring Technical Standards Conformity Certification Episode 3 “Examination”
Using an evaluation board that has not been technically certified violates the Radio Law, so the members who have been involved in obtaining technical certifications have only evaluated wireless communication in a limited environment. . Therefore, I have never tested how long Sub-GHz band wireless communication can fly outdoors.
This time, I want to use it because I have acquired the technical suitability! In the first part and the second part, we will deliver the experimental results of actually measuring the flight distance of wireless communication in the Sub-GHz band by several engineers who felt that.
Prepare to measure Sub-GHz band communication
A brief description of the preparations before taking measurements.
Sub-GHz band communication measurement overview
We fixed the sending side and moved the receiving side to check how far the packets would reach. The sending side emitted radio waves from the roof of Macnica Building so that the packets would travel as far as possible.
Software settings
In this measurement, I would like to check how far packets can reach based on the packet transmission test used when I took the technical conformity test.
Hardware preparation
I also applied for multiple antennas when I acquired the technical suit, so I'm wondering if the type of antenna will affect the flight distance. So, I would like to fix the antenna on the transmitting side to the onboard antenna and change the antenna on the receiving side to the following antenna, and check how much the communication is affected.
Various antennas that connect to TI's evaluation boards
1. Onboard antenna on LaunchPad
2. No.12 antenna from Antenna DK
taoglas antenna
3.FW.95.B.SMA.M
4.TI.09.A.0111
The power supply supplies power by setting a cable from the USB port of the PC.
There is a very handmade feeling, and anxiety remains, but for the time being it is completed. The cardboard color is slightly different in the photo on the right, but there's a reason for that...
Unexpected! Measured in bad weather
Unfortunately, it rained on the day of the measurement. Measurements can be taken even in the rain, but if you look at the cardboard work again, the circuit board will still be exposed, right?
If the board body gets wet and a short circuit occurs, it is obvious that it will break down. However, I can't help but measure with the exhilaration of being able to acquire technical suitability. I took care of the short circuit and put an umbrella to protect the board and headed for the measurement.
In the cold weather (the measurement date was in mid-January), it was strange to walk around with an umbrella and a cardboard box and a PC.
However, contrary to the lonely figure of the engineer who is measuring, the distance is getting longer and longer. I assumed that the flight distance would be about 500m and I would not be able to communicate, but I don't know where to stay.
Although there was a difference in the packet error rate, there was no loss of communication with any antenna, and surprisingly, we were able to communicate up to a distance of 580m from the building.
I'm worried about the rain and hardware failure, so I went back to the company here this time.
What I learned from measuring Sub-GHz communication
Unfortunately, I was not able to confirm the ability of Sub-GHz communication this time, but I was able to confirm that it can fly at least 500m or more. If you can get this far, it seems that you can apply it to various solutions. In addition, I learned the following three points from this measurement.
1. A case with built-in evaluation board is required
The characteristics of the antenna may be affected by human touch, but it is also necessary to consider waterproofing measures to deal with sudden rain.
2. Requires a button that can be touched from outside the case
It's hard to tell from the photo of the cardboard box, but the antenna outside and the board inside are connected with a very thin wire. Even a slight deviation will cause the antenna to come off. In addition, the software settings are operated by onboard buttons. Therefore, I had to operate the buttons without opening the box as wide as possible, which was very inconvenient.
3. Weather matters
I forced the measurement in bad weather, but I had to worry about the board, so I was very nervous. A sunny day is recommended for wireless communication measurements.
It's frustrating, so I'll try again next time!
Based on this reflection, I would like to improve the evaluation board. Praying for good weather, the second part will deliver the results of an experiment using an improved board. Please look forward to the results of the re-challenge!
Contact Us
If you are looking for detailed information on TI's development kits introduced in this article or Sub-GHz compatible products, please contact us here.
Related information
Click here for recommended articles/materials
I tried to measure the flight distance of Sub-GHz band wireless communication Part 1 "Let's try it first"
I tried to measure the flying distance of Sub-GHz band wireless communication Part 2 "Improved and challenged 2 km"
The road to technical standard conformity certification Episode 1 "Let's get technical standards"
The Road to Technical Regulations Conformity Certification Episode 2 "Preparing Documents"
The Road to Acquiring Technical Standards Conformity Certification Episode 3 “Examination”
Click here for recommended seminars/workshops
Wireless Seminar for Beginners - First wireless product starting with TI - <free>
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LAUNCHXL-CC1310
*Since this evaluation board has not acquired domestic technical certification, please use it at your own discretion.