sonar data link

I came across this ariticle on how to make a sonar datalink using arduino, it looks pretty simple, has anyone tried a sonar link before?

https://www.edn.com/exploring-software-defined-radio-without-the-annoying-rf-part-1/
https://www.edn.com/exploring-software-defined-radio-without-the-annoying-rf-part-2/

code is here
https://www.thingiverse.com/thing:6268613/files

No, not that I am aware of and there should be!

There have been various "thought experiments" and claims made about successful systems but nothing that seems to have come to anything. A lot of it seems to have been focused on model control rather than telemetry.

Put it this way, the ponds are not thronged by model submariners using ultrasonic control systems!

I developed the ultrasonic Pinger for lost model location but this was only designed for good battery life and the useful directional cone from an ultrasonic transducer.

So please have a go. Suitable underwater transducers are quite cheap now - have a look at the Pinger design.

I also like the idea of using SDR principles for ultrasound rather than radio. An analogue of WSPR or FT8 radio technology could reject a lot of noise in a noisy underwater environment?

David

I have been thinking that this could all probably be done in software with an esp32, similar to the esp32 phased sonar array I looked into a while back. Since it has a built-in DAC that could generate tones and an ADC that could decode them as far as I can tell the hardware should be capable of it with just an amplifier on the input and output.

This looks very promising !

https://github.com/ggerganov/ggwave



I was thinking about your pinger, what about if a pair of sonar transducers were used, so one pings, then the other pings back after a set time, then you could use that to calculate the distance between them using the (time - delay), by adding the delay it gives time for reflections to dissipate before sending a response. if you have a pair on the receiver then you could look at the time difference to give you a direction.

This one relies on  light pulses
https://youtu.be/Sh3igUyK7Sc?si=QgalAONWTgomRjEc

That's cool, I have seen something similar using a small led and a fibre optic but it never occurred to me to forget the fibre and just use a giant LED.

I wonder if a pair of these could be modified to do that, essentially just add a lens to the receiver and a large LED to the transmitter.

https://www.ebay.co.uk/itm/305651031084


looks like it can be done with arduino, this is very interesting, I have a lot of stuff on the go at the moment but I'm going to come back around to this at some point to build something like a little ROV that is controlled from my tug using audio and light. they were getting 3m with a 1w led. so there is room for improvement. the video showing that exray sub shows a massive COB LED, probably 30 or 50w. even with that amount of power it's still going to be limited to very clear water.

https://github.com/jpiat/arduino


I have been thinking some more about what this could be used for, and the best idea i have is for a moving baseline position system. Essentially if we have 2 sonar transducers with some separation as a baseline then a pinger on the sub to respond, the baseline sends a ping that tells the sub to respond with a ping exactly a set time after its received, the difference in the time the ping arrives at both baseline transducers could give you direction and the response time will give you range, so if you know the position of the baseline you can work out the position of the sub and send that back via the sonar data link.

most of it already exists so it would only take some small modifications to makle it a transponder system.

https://www.hackster.io/abhilashpatel121/ultrasound-sensor-2d-tracking-with-arduino-d0b974