LoRa Underwater Test: Can LoRa Survive Underwater? 433MHz vs 866MHz Battle
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LoRa Underwater Test:
Can LoRa send signals from Underwater? LoRa Underwater Test with 433MHz vs 866MHz
I am testing 433MHz versus 866MHz LoRa.
Bucket, Drum, and River; to see which one survives the deep end.
Stick around for the winner!
Water is supposed to kill wireless signals, right? WiFi hates it, Bluetooth barely works; so I wondered: can LoRa, these low-power, long-range tech, break the rules?
I am putting two frequencies against each other: 433MHz and 866MHz.
Lower frequency might punch through water better, but higher could surprise us.
We are starting small, and then going big- bucket, drum, and a real river. Which one is the king? Let’s dive in.
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About the setup:
Check this; the 866MHz pair is alive! You are watching; it beam numbers wirelessly to the receiver right now. Outside water, this thing hits over a kilometer. I proved it in my previous article.
Underwater range? No clue yet – total mystery! But here is the deal: when the receiver stops counting, we will know that the signals are not coming through the water.
And this is our 433MHz setup, which I have used in many projects. Same program, same mission: firing numbers to the receiver.
You can download all the 4 programs from my Patreon Page.
Water is the enemy, so I am sealing it up and for that, I am going to place the transmitter side into a plastic container.
But before that, let me quickly tell you about the power supply.
This is my custom-designed 5V 3A power supply, and with it, I will be using my self-made 4S lithium-ion battery pack.
I can’t afford even a tiny risk, so I am putting this container inside a plastic bag too;
And with it, I am going to add a little weight so it dips properly into the water.
I have used double shoppers so I am pretty sure it’s going to be totally safe.
I have packed the transmitter side well, and as you can see, the counting is being received on the receiver. Our setup is completely ready for the first test.
LoRa Underwater Test 1: The Bucket
Just a foot of water
First we will check out the 866MHz LoRa modules.
This is Crazy! The transmitter side is completely submerged underwater, and the transmitter is still able to communicate wirelessly from inside the water. This is something I have never done before, nor has anyone else so far.
It’s communicating quite easily from inside the bucket because there is only about 1 foot of water in it, but still, it’s quite impressive. Right now the receiver is quite close to it, but in next experiments, we will also increase the range. And that’s when the true power of these LoRa modules will be revealed.
Anyway; now, we will check the 433MHz LoRa modules. As you can see, numbers are being received on the receiver. They communicate well outside the water, let’s see what happens after dipping the Transmitter side LoRa underwater.
The transmitter is completely underwater and numbers are still being received on the receiver.
Water is getting inside the shopper, but I am not worried, because I have used double shoppers. So, the transmitter side is going to be perfectly fine.
LoRa’s low frequency cuts through better than 866Mhz.
Anyways; The 1 Foot underwater test for both LoRa modules has been successfully passed.
LoRa Underwater Test 2: the drum.
This is 4 times the depth, and its diameter is also slightly bigger than the Bucket. If both LoRa modules survive this test as well, then we will head to the River side.
Before this, the box wasn’t dipping underwater, so this time I put a 4Kg weight with it. Hopefully, this time, it will dip properly underwater.
Right now, the transmitter is at the very bottom, water is also getting inside the shopper, but I am not worried because there is another shopper inside it, and then inside that shopper, the transmitter is in a box. So, it won’t get damaged.
I am going to move a short distance away to test the effective range of this 866 MHz LoRa module in practice. As you are aware, radio signals experience attenuation underwater.
According to theory, lower frequencies maintain their strength better, while higher frequencies, such as this 866 MHz, suffer greater signal loss due to water’s properties. Now, we will put that theory to the test and determine the actual performance firsthand.
Right now, my distance from the transmitter is around 25 meters, and the receiver is still receiving the count. Now I am going to increase my distance a bit more.
As soon as I went behind the wall, the receiver stopped receiving data. If there wasn’t a wall and it was open space, it might have covered a greater range. By the way, the type of antenna also matters a lot. I have already written quite a detailed article on different types of LoRa antennas.
Now, 433MHz LoRa transmitter.
As per the theory, 433MHz LoRa modules should perform a bit better than 866Mhz. Let’s check it out.
Amazing, it’s working as expected. Now we will check the receiver’s distance; it should cover a greater distance because of the low frequency and the FPC type antenna.
It’s still working even after coming behind the wall.
Now I have come outside the house; there are many walls in between, and the receiver is still receiving numbers. When I go further away than this, the communication stops. If I had used a suction cup antenna instead of the FPC antenna, the range might have been a bit more. If there were no walls in between, the range would have been much greater.
So, in this test, the 433Mhz LoRa modules are the winner!
It performed well at a 4 feet depth, but how does it perform in more water and increased depth? For that, I will have to go to the River side. So, let’s quickly take the Transmitter out of the water and head to the River side.
LoRa Underwater Test 3: The River
We have reached the river side, and the water flow is quite strong, so going in the boat and testing in the middle of the river isn’t possible.
After searching for quite some time, we have finally found a spot right here on the bank where the water is quite deep. If it works even in this deepwater, then it’s going to be a wow moment.
This time, I have changed the setup a little bit. This time I am also using a measuring tape along with the rope so that we know the depth accurately.
Looking good! The data stream is solid on the receiver. Let’s see if 866MHz can handle the pressure, everything looks just fine. So, let’s start the test.
The counting has stopped on the receiver. 2.9 feet is the maximum depth distance from where the 866MHz LoRa transmitter can effectively communicate.
Now, let’s check the 433MHz LoRa modules.
The numbers are streaming in perfectly on the receiver, everything looks just fine. Let’s take the transmitter side underwater now and let’s see if the 433MHz LoRa module could give us a slightly larger communication distance.
This is absolutely mind-blowing, we have already crossed 3 feet, and the receiver is still receiving the count.
The measuring tape has also completely submerged underwater.
The transmitter side has now reached the bottom of the water; it can’t go any further down, numbers are STILL making their way wirelessly to the receiver!
It’s like magic happening underwater! The transmitter side LoRa is currently 6.25 feet deep underwater, and communication is still ongoing. I am sure it will easily go up to 10 feet or even more.
Anyway, in this underwater test, 433MHz LoRa is the winner!
There is no doubt that the communication distance of LoRa significantly reduces underwater, but still, you can use it in many projects. If you guys have any ideas related to this in your mind, you can share them with me; I will try to make a video on it.
So, that’s all for now.
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