Ultrasonic distance measurement

I am currently using an HCSR-04 ultrasonic distance measuring device with an Arduino Nano for monitoring the water level in my swimming pool. It transmits the level to a website where I can see it from anywhere. The sensor is 10 cm above the nominal water level and it provides the current level. Everything works fine except for the fact that the sensor tends to corrode and malfunction after 6 months due to the humid environment. I am looking for the equivalent sensor, but hermetically sealed to avoid degradation. I came across a sealed sensor A02YYUW shown below. I am looking for a few opinions on this device for those who have used it. Thank you.

A02YYUW Waterproof Ultrasonic Sensor Wiki - DFRobot

I have not used either of the devices, but I am sure you have read the link you gave and can see the two devices are TOTALLY different in connection and software. So, I am sure it will work for you, but you need to start with a completely new program. The part sending data the web site can stay the same.


  1. I will have to make a new bracket (3D printer) to connect it to my pool.
  2. A different connector to my Nano perfboard.
  3. Create a new function and use a 2nd software serial connection (1st is used for the Lora xmit AT-commands).

No problem there

But I was wondering about the precision and reliable of each distance measurement. Also whether the measurements are corrected by temperature variation of the sound velocity. I don't find any users of this device on Youtube.

Are you aware of the drawbacks of using multiple software serial instances?

yes. I am using 2 softwareserial interfaces in one of my modules. Connected to esp-01 with one and RYLR896 on another. The key is to use mySerialx.listen() and not to use simultaneous connections. And cool on the Baudrates. I keep it at 9600. Works fine! What other drawbacks do you know of? I'm always interested in any additional limitations

You hit the ones that I was thinking about. If it works well enough for you, great. It just that I have seen many people try to use more than one and have trouble cause they don't know that only one instance can be active at a time.

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