JSN-SR04T Depth sounder

I happened to be talking to a Russian guy that informed me that they have discovered you can use the JSN-SR04T ultrasonic sensor underwater as a Depth sounder, its popular on their bait boats. it works essentially the same as the classic SR04 ultrasonic sensor, all you need to do is change your code to compensate for the faster speed of sound to get it working accurately.

Looks very good.

Do you have any more information? Links etc?

(i wonder how they re-programmed it?)

David

Wow! Add some depth charge throwers and you're all set hunting U boats in the pond.

david f wrote:Looks very good.

Do you have any more information? Links etc?

(i wonder how they re-programmed it?)

David

I am not sure how they have programmed the controllers, but the sensor works the same as the sr04 sensor and there are many many instructional pages on how to use them with arduino, the only modification you need to do is change the constant for the speed of sound in water.

I have been doing more testing with these sensors and have a much better understanding of their capabilities,

The single transducer JSN-SR04T works to almost 10 meters but has a minimum working depth of 1.5m so its not ideal for smaller boats in shallow water
The dual transducer  JSN-SR20-Y1has separate transmit and receive transducers so it doesn't need to finish transmission before it can listen, this means it works in as little as 15cm of water under the boat.
The A02YYUW ultrasonic sensor is basically an encapsulated version of the JSN-SR20-Y1 that  can just be attached to the bottom of a hull.


so where I think this could be useful for RC submarines is terrain avoidance. The boat club I used to be a member of had a concrete pond that was only 2 foot deep so all the subs would end up with big scrapes along the bottom where they dived a little too far. using one of the dual transducer sonars would let you set a minimum depth of water under the boat, so it wouldn't dive lower unless there was enough water under the boat

here is an example of how to drive a servo using the sonar and arduino, you just need to up the constant from 29.1 to 125.1 to compensate for the faster speed of sound in water.

https://create.arduino.cc/projecthub/anjalishaw1125/servo-motor-ultrasonic-sensor-e69be3



I'm looking into a making a sonar array for locating underwater objects like fish, sub hide and seek might become a thing lol

arduino phased sonar array, my plan is to mount one under a boat for scanning for underwater objects.

Hello geofrancis,

Just reading this thread - not sure if I am misreading your posts.

Have you got ultrasonic distance sensing working underwater to 10m?

Regards
Jonathan

C-3PO wrote:Hello geofrancis,

Just reading this thread - not sure if I am misreading your posts.

Have you got ultrasonic distance sensing working underwater to 10m?

Regards
Jonathan

I have only tested to a couple of meters, but there are videos of others using it to 10m using the JSN-SR04 sonar it will work underwater using standard sr04 code, all that needs to be changed is the speed of sound to get the measurements to line up. I have been testing these for use on autonomous boats but the tech would work well on subs just as well to stop running aground.

The dual transducer variant is much better for smaller boats as it will work in as little as 15cm of water where the single transducer has a minimum distance of 1.4m in water.


https://discuss.ardupilot.org/t/sonar-based-on-hc-sr04/80476/7

Hi geofrancis,

Thank you for the info - I can see me revisting a previously failed experiment

Regards
Jonathan

C-3PO wrote:Hi geofrancis,

Thank you for the info - I can see me revisting a previously failed experiment

Regards
Jonathan

Sounds interesting, can you elaborate?

Hi geofrancis,

I have been exploring as a joint project with another guy what you can achieve with ranging solutions - we have been looking at ultrasonic, lidar and rf based radar.

We have had mixed success so far but it's still early days - it's a great "duo" as he is an electronics whizz and I get by with coding :)

Regards
Jonathan _._

C-3PO wrote:Hi geofrancis,

I have been exploring as a joint project with another guy what you can achieve with ranging solutions - we have been looking at ultrasonic, lidar and rf based radar.

We have had mixed success so far but it's still early days - it's a great "duo" as he is an electronics whizz and I get by with coding :)

Regards
Jonathan _._

I could probably help, I'm working on sonar arrays for autonomous boats and collision avoidance using a rotating radar system combined with a lidar array. I have tested a lot of different sensors, what are you looking to detect and is it above or under water?

https://discuss.ardupilot.org/t/scanning-rangefinder/81131/31

Hi geofrancis,

Maybe we should compare notes at some point.



Right now this project is back burnered whilst we mess sround with a new concept of a sub leveller

Regards
Jonathan

C-3PO wrote:Hi geofrancis,

Maybe we should compare notes at some point.



Right now this project is back burnered whilst we mess sround with a new concept of a sub leveller

Regards
Jonathan

I think the best approach would be the phased array sonar system from the video I linked to earlier,
https://youtu.be/z4uxC7ISd-c?t=826

I had a look through the code for it here https://github.com/bitluni/SonarScannerV1 and from what I can tell all that would need to be changed is the constant for the speed of sound and changing the transducers for waterproof versions like what I have been using on the depth sounder.

Hi geofrancis,

Have you got any range results from the FMK24-E5200 module?

I know spec states upto 20m and also see some people have struggled to achieve 3m...

Interested in your project experience/results

Regards

Jonathan

C-3PO wrote:Hi geofrancis,

Have you got any range results from the  FMK24-E5200 module?

I know spec states upto 20m and also see some people have struggled to achieve 3m...

Interested in your project experience/results

Regards

Jonathan

yes it worked and I was getting a decent range on it, but i didnt get to do any objective testing on it before I sent it to the software developer to get the driver done. I am getting another one soon for follow up testing now I have a functioning driver interface for the rover control software.

Hello geofrances,

I have been playingf with the JSN SR04T V2.0 single transducer in water and cannot get a squeak out of it.

I must be missing something obvious

Can I ask which JSN SR04T mode you are using (serial?)

What is that latest result you have with regard to distance you can detect?

What code are you using with the JSn board - standard library?

Currently I have given up with the JSN board and along with an electronics wizard are currently recreating the a solution from scratch - however still no ultrasonic  squeaks - well half of one :)

Thank in advance
Jonathan

C-3PO wrote:Hello geofrances,

I have been playingf with the JSN SR04T V2.0 single transducer in water and cannot get a squeak out of it.

How deep was the water you were testing in? you wont get any readings in water less than 1.5m deep with a single transducer sr04 sonar.

the dual transducer version works at much shorter range, around 3cm in air and 15cm in water.


this is the code i used to get mine working.
https://dronebotworkshop.com/waterproof-ultrasonic/

I have 4 installed in my boat hull, singe transducer sr04 facing forwards and down around 40 degrees, and dual transducers to the left right and down.

Thank you for the update and pointers

I'll give it a go and see what happens...

Getting close with homebrew solution which generates it's own pulse(s), has it's own receiver, and uses our software so we are in control - it only uses the ultrasonic tranducer from the commercially available toys

Fingers crossed

Give me a ping, Vasily. One ping only, please

Regards
Jonathan

I am working on a phased array using the sonar modules being driven by an ESP32 and brushed motor drivers.






https://github.com/geofrancis/SonarScannerV1

Hi GeoFrancis,

Wow - that looks a complex setup...

What are you using to receive the ping from the phased array - JSN boards?

Will you be monitoring things live on the shore or recording data for offline processing?

Reqards
Jonathan

no the JSN boards are for single direction distance measurement, on the phased array there is more of an image created.

Im using DC motor drivers to drive the ping and a small amplifier board on the receiver. I actually burnt out the drivers in that photo by applying 12v when I forgot they are only rated for 9v and have new pair of 4 channel drivers to try.
https://www.aliexpress.com/item/4000054713222.html

https://www.aliexpress.com/item/1005001459028317.html

https://www.aliexpress.com/item/32816065152.html

this is the kind of image i hope to get from it. The plan is to be able to visually see the the output and to be able to feed it into the ardupilot proximity system so it can be used for avoidance.

made some progress, its basically working now it just needs tuning, i think some things are backwards and out of order..

Progress stalled on the phased sonar, possibly due to noise in the motor drivers, but il look at it again another time.

So.. i moved onto my other idea, and that was taking a sonar transducer and mounting it to a servo so i can scan underwater, it should work up to around 10m, the sonar can do around 10hz and its processed as 72 slices so max speed is around 1 scan every 7.2 seconds. It should make a good fish finder.

I have been working on a little project for a blind RC boat modeller, the idea is to essentially use 3x sr04 rangefinders pointing forward, and 45 degrees left and 45 degrees right, to detect if its going to run into anything then generate a tone like a parking sensor to let them acoustically navigate obstacles using stereo headphones connected over bluetooth, but it occurs to me that using the waterproof sonar modules this would also work underwater if you use something like a fm transmitter rather than Bluetooth.

its still a work in progress.

https://github.com/geofrancis/Acustic-navigation/blob/main/Main.ino