sonar/fishfinder/object detector?

[seabass]

I am not sure if this is a feature request or something else, as I am just getting to grasp of a rough outline of what this software can already do.
Is there an open-source fishfinder tool/plugin that can interpret/control commercially available transducers already?
I really HATE the vendor lock-ins and artificial limitations that most commercial vendors of GPS+sonar fishfinders sell, and I have been looking for a way to hack my own together, and finding OpenMarine, I got excited that others might already be working on something like this that would run on IOS and Android, or a Linux tablet.
So I am hoping someone has an inkling of a project like this if it does not already exist.
Thank you for the opportunity to commiserate with fellow maker+boaters
S

[seandepagnier]

I have started a project and so far I am measuring depth. The first prototype works.

It can drive any type of existing transducer, however it only has one channel so doesn't do beamforming or transducers with multiple units yet. I am testing with one i got on amazon for $50

I also need to work more on dopplar so it can measure water speed, it only does the normal scan.

My resolution is not that good 20-30cm, and max depth only about 15 meters.

At 10 pings per second surprisingly, the microprocessor uses 90% of the power, so with some optimizations the total power draw would be like 1/4th watt it seems.

So I need to do more work I have another design I am adding an esp32 to give it a web interface accessible wirelessly. Also making the analog frontend have far lower noise and using a superior processor for better algorithms.

One issue is it is hard to find specs on the airmar transducers for how much voltage they can take. I am driving this one at 120 volts. Eventually i want to add interface to autocalibrate, and detect the resonant frequency etc, and make support in opencpn survey plugin to make creating charts simple.

[BellaX]

Hi Sean,

you are welcome to get in contact with Jan:
https://github.com/Neumi/open_echo

He did a pcb based on the TI TUSS4470 and some software to test is. You can follow him on sailing forum:
https://www.segeln-forum.de/thread/74825...?pageNo=13

I started the thread some years ago but didn´t find the time to push it. I made a pcb based on the PW0268 but this chip is very, hm 'analogue'
and does not really work. I have focussed on the TUSS4470 then but never came to the point to test it. My boat is in the water from may to september
and sailing time is not development time so the project didn´t step forward.

I am happy Jan has taken over, he is using the same chip and has better testing environment (he lives close to the baltic sea)

Chris

[seandepagnier]

It is really an interesting chip but the voltage is limited... my version boosts to over 100 volts for echos up to 15 meters deep.

I am seriously looking into doing beamforming now to support scanning type sonar.

[BellaX]

It is really an interesting chip but the voltage is limited... my version boosts to over 100 volts for echos up to 15 meters deep.

I am seriously looking into doing beamforming now to support scanning type sonar.

Jan got echos from 46 meters maximum with supply for the transducer of 25 V. The chip has programmable filters,
gain and threshold. The echo frequency has to be supplied from the microcontroller so it can be adjusted to the resonance
frequency of the transducer.

Adding a matching transformer is easy. But this transformer has to be tuned by hand and works for one frequency and transducer then.
If you change the cable lengths you have to match it again.

Both principles have their own advantages. I think for a DIY depth meter the direct drive without transformer makes sense.

Chris

[seandepagnier]

does the transformer boost voltage further?

46 meters is quite deep! I would be happy with 15-20. I am trying also to keep the support generic so I have my own chain.

This is mainly because I wish to extend to beam forming for side-scan support. It needs to drive with phase changes and receive data that it can coherently correlate. Also possible for it to automatically detect the correct frequency.

the other issue with the transformer is assembly is more expensive and difficult. Still very interesting to compare different approaches.

[BellaX]

does the transformer boost voltage further?

46 meters is quite deep!  I would be happy with 15-20.  I am trying also to keep the support generic so I have my own chain.

This is mainly because I wish to extend to beam forming for side-scan support.  It needs to drive with phase changes and receive data that it can coherently correlate.  Also possible for it to automatically detect the correct frequency.

the other issue with the transformer is assembly is more expensive and difficult.  Still very interesting to compare different approaches.

Have you seen the homepage of Thomas Rapp? He played around with DIY sidescan and transducers: rapp-instruments

He lives in Munich (like me). I have contacted him two years ago. He has sent me some of the 100 KHz piezos he was using for his experiments.
I made a transducer by myself based on a milled cup of polyurethane. Than glued the piezo to the bottom and filled up with 2k silicone.

I have sent it to Jan and he will test it with his hardware.

Chris

[schrammie]

Hi all,

I am trying with Jan the Airmar (or Raymarine) P319 transducer (not expensive and 50/200hz) on his board, with the raspberry pi openplotter config. The reseon iam going for the Airmar P319 is that my boat is a midswoard and aim sailing on the waddensea, falling a lot dry (dont jknow the english term), in Dutch droogvallen. So we hope to get it running the project. 

So let you know about the results.