I finally opened my store again:
https://pypilot.org/opencart/
I have minimal products available, but with a hat and motor controller it's possible to make a working pypilot system.
I intend to have high power controllers (30 amps) again soon, as well as many products in the future though it will take more time.
Right now I am working on:
1) fully waterproof pypilot computer with 3.5 inch screen. much larger display higher resolution and 4 grey rendering
2) multi function displays fully waterproof monochrome and color daylight visible can plot most instruments including history plots and gauges.
3) fully wireless 3d printed wind instruments running on tiny solar cell to mount anywhere with 10hz output rate and integrated IMU to compensate boat motion.
4) depth transducer driver (work with existing depth transducers or using 200khz transducers available for about $50) creates wireless fish finder with full control of driver an receiver.
All of these have working prototypes so far.
Then further on I still intend to make the sonar measure water speed then also do a phased array sonar for true 3d mapping and several other ideas.
The prices are unfortunately higher now because of recent tariffs imposed in the USA that actually increased cost to produce by 45% which is a huge change from 1 year before.
According to my basic calculations, average power of 2mW using 100mW solar panel should work all the time in most locations most of the time.
I intend to reduce the output rate of 10hz to 5, 2 then 1hz when power is limited which gets the draw < 1mW, but even still there are locations in higher latitudes and/or winter with enough overcast it will not work. It becomes impossible in polar regions in the winter. I am using LTO cells which can handle extreme temperatures and also very long life.
Because sailing in these places in the winter is likely limited, I did not worry about it too much, but I have a powered version of the wind sensor as well.
Sean,
Great to see your store is open again. I once ordered one of your hats but later on I made my own. I sold the hat and I was amazed how much people wanted to buy it. I hate to admit it, but the the bidding war that started resulted in a higher price than I paid for it.
I am really looking forward to your wind instrument and depth transducer, and speed sonar. Those are 3 things that I have on my list as well to develop in this year. Will the code be Open source? If yes, do you have any plans when you will you publish the work? I assume it is C++? Wireless protocol will be BLE, radio or ESPNow?
I have espnow wind sensors already but the problem is the power is not low enough to run on a tiny solar cell, so this version requires power wires (just 2 wires) and the data is wireless.
The fully wireless version must use a 900mhz (or can do also 868) with a bit of complication FSK type encoding.
As for the depth, I continue to develop and probably cant do actual testing for a few months but so far I have made incredible progress on the signal processing. I hope to eventually make phased arrays for 3d mapping.
Curious Sean of what you will see. I was checking your GitHub to see if there is something to see.
My personal problem on my boat is that I navigate in very shallow waters and my boat draft is only 80cm. Most depth sensor wont work. I was planning to make my own. I got a lot of resource at hand. Time, 3D printing, PCB manufacturing and testing opportunities. Season starts next week here and my aim was to make it for this summer.
Let me know if I can assist you.
(2026-03-20, 05:18 PM)PieterO Wrote: [ -> ]Curious Sean of what you will see. I was checking your GitHub to see if there is something to see.
My personal problem on my boat is that I navigate in very shallow waters and my boat draft is only 80cm. Most depth sensor wont work. I was planning to make my own. I got a lot of resource at hand. Time, 3D printing, PCB manufacturing and testing opportunities. Season starts next week here and my aim was to make it for this summer.
Let me know if I can assist you.
Check out OpenEcho project, might be useful for this!
https://github.com/neumi/open_echo
Ive seen that project but not sure it will really work that well given the design choices.
As for 80cm, is a challenge. Especially if the transducer is at this depth and only a few cm from the bottom.
By the time the pulse is received, the transducer is still ringing from transmit, so it is hard to measure.
My boat draft is 60cm, I will be trying also at shallow depths, I think it might have to detect depth an adjust pulse length, perhaps use active dampening and so on.
Despite this other depth sounders I have used can measure below 1 meter depth so not sure exactly what you are doing.
(2026-03-26, 11:58 PM)seandepagnier Wrote: [ -> ]Ive seen that project but not sure it will really work that well given the design choices.
As for 80cm, is a challenge. Especially if the transducer is at this depth and only a few cm from the bottom.
By the time the pulse is received, the transducer is still ringing from transmit, so it is hard to measure.
My boat draft is 60cm, I will be trying also at shallow depths, I think it might have to detect depth an adjust pulse length, perhaps use active dampening and so on.
Despite this other depth sounders I have used can measure below 1 meter depth so not sure exactly what you are doing.
Interested to here what design choices you have issues with? I run an open echo device on my yacht and it works perfectly (I have personally tested down to about 20m, I know others have seen down to 40+ but I have not been anywhere that deep recently). It even works with either of my on board transducers, a 1970s 150kHz and an early 2000s 192kHz, both of which are bonded to the hull.
My 150kHz has a very small ringdown, around 30cm at the voltage I am driving it at (~30V), so would work well for a shallow draft like yours I guess?
Well this is great to hear from someone using open echo and get feedback as I had not seen much besides one youtube video.
Yes! certainly the ringdown at only 30 volts is less time, and this is the right solution, if it detects the depth is shallow, then it can use less voltage and shorter pings to reduce ringdown time, so it can work adaptively. I also intend to experiment with active dampening as well.
I think one of my main issues with open echo is it does not sweep frequency in a chirp. So correct me if I am wrong, but what I am doing is also allowing a variable bandwidth, and the pulse is sent sweeping this bandwidth. Some transducers have wider bandwidth than others. The return is then computed a FFT, along with FFT of the chirp and these are convolved in frequency space then inverted with IFFT. This mathematically produces a much sharper depth measurement, in fact it allows accuracy down to centimeters (the exact resolution depends on bandwidth) while allowing the pulse energy to spread across several milliseconds which it is not possible with a simple ping, this is the "chirp" sonar.
So this is my issue with the ti part the tuss4470, it has many limitations, and although it is much cheaper, the electronics I have are still cheaper than the transducer itself. Most transducers can handle higher voltages (up to 100 volts) which results in potentially (depending on unit again) both higher efficiency from much shorter pulse needed as well as better clarity and certainly more range, but this part limits driving to about 30 volts, probably designed for air not water??
If 30v works at 40 meters then this is less of a question, but probably at only 200khz or less though that is quite good to know. Perhaps the analog receiving part is very good. At higher frequencies like 800khz much more power might be needed and those higher frequencies have much better resolution and are desirable for mapping or imaging.
Eventually for a phased array with many elements, I dont think the TI part could ever be used as the channels would not be synchronized in time so no way to perform the beamforming computations.
If a cheaper transducer (< $20) can be found or reusing an existing one, then the open echo in absolute terms is much cheaper, especially to just get depth, and this is interesting and useful for that reason, but I am trying to produce higher resolution images with more user configurable variables, and the cost $30 or $40 more for the electronics. What do you think?