OPEN ECHO: OPEN-SOURCE SONAR THAT MAPS THE SEABED, FISH AND SEDIMENT LAYERS FROM AN ARDUINO SHIELD
An open-source echosounder that runs on an Arduino Uno and shows you the seabed 38 metres below the boat.
by Jan Neumann
ScienceOpen-hardware
Built withArduino
- difficulty
- ●●●●○
- time
- a weekend-plus
- license
- none
- repo
- repo ACTIVE502 stars
●●●●○ · a weekend-plus · none · 502 stars · repo ACTIVE
WHAT YOU’LL NEED
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COMPAREE VERDICT
Open Echo is a working single-beam echosounder built around a TI TUSS4470 ultrasonic driver on an Arduino shield. The repo includes the board files, firmware for Arduino and a Python interface that renders a live waterfall echogram, and real test data from the Baltic Sea including a 38 m range test, sediment layers and fish. The author has published six videos about it and asks users to cite the project with his ORCID. The catch: there is no licence file, so you cannot assume commercial use is permitted. The KiCad files ship with Gerbers and a production BOM if you want to have it made yourself rather than buying the Elecrow board, which lists at 78 dollars but is currently out of stock; the author also sells boards directly within Germany and the EU. A transducer adds roughly 5 to 200 EUR depending on what you choose, with the 150 kHz Seafarer used in the Baltic tests at 50 to 100 EUR. The single hardest part is not soldering or firmware — it is choosing and mounting a transducer without flooding the hull. If you want an echosounder for a USV, ROV or research project and you are prepared to interpret raw echograms rather than processed depth, this is a credible starting point. If you expect a plug-and-play fishfinder with a colour screen, this is not it.
IN THE REPO
GOOD TO KNOW
- —The repository has no licence file — redistribution and commercial use are undefined. Do not assume it is free to sell.
- —Complete KiCad PCB files for the shield_002 board (May 2025) are present, along with Gerbers.
- —Firmware for both Arduino and Python interface software is included, with NMEA0183 output support.
- —The README documents transducer choices, power requirements, test results from the Baltic and a full citation for academic use.
- —A ready-made board is sold by Elecrow for 78 dollars, currently out of stock. You can order from the files at any PCB house.
- —A production BOM (bom.csv) and pick-and-place files sit next to the Gerbers; transducer choices are documented separately in the README.
Parts to buy
5 itemsFrom our check of the build. Exact quantities and part numbers are in the creator’s BOM.
Can I build this?
Build at your own risk. Projects involve tools, electronics and sometimes mains voltage — follow the creator’s safety notes.
Videos
What Happened to Open Echo? A whole lot! (the movie)33:00
Published 2025-10-01 on the Neumi channel, linked from the README as 'LINK TO LATEST VIDEO'. Shows the shield_002 PCB, live echograms with depth readout, and real measurements from a sailing yacht on the Baltic. The channel has six Open Echo videos; this is the most recent.
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Start here
Navigation into the creator’s own docs — we don’t rewrite the guide, we route you to the source.
- 1.Decide on transducer frequency and mounting (The README lists tested transducers from 40 kHz to 1000 kHz. The NASA/Seafarer 150 kHz is 50-100 EUR and was used for the Baltic tests. Higher frequency gives better resolution but shorter range.)
- 2.Buy or order the shield(The Elecrow board is 78 dollars but currently out of stock. Alternatively, order from the KiCad files at any PCB house — Gerbers are in the repo.)
- 3.Flash the Arduino firmware(Two firmware options: one streams raw samples to the Python interface, the other outputs NMEA0183 DBT depth sentences to a serial device or Pixhawk.)
- 4.Run the Python interface to see live echograms(The Python software renders a waterfall display, changes board settings and outputs TCP depth. Requires a PC or Raspberry Pi.)
Resources
Documentation, files and community threads for this build — we link straight to the original sources and never rehost the creator’s files.
KNOWN ISSUES
- The repository has no licence file. You cannot assume commercial use, redistribution or modification rights are granted. If you plan to sell this or use it commercially, contact the author first.
- The Elecrow board may be out of stock. Ordering from the files yourself is possible — the KiCad project ships with Gerbers and a production BOM (bom.csv) — but you will be sourcing and assembling the parts yourself.
- Transducer mounting is the single hardest part. A bad through-hull fitting will flood the boat. If you have never installed a transducer, practice on a test hull or use a portable mount first.
- The board captures only 8-bit samples, so dynamic range is limited. In very shallow or very deep water, you may need to adjust gain and delay manually — there is no auto-ranging.
- The Python interface is not a polished app. It is a development tool. Do not expect a consumer fishfinder GUI with waypoints and alarms.
- The transducer needs 15-20 V. The README's tests used an MT3608 boost converter from USB power, which currently requires manual soldering; a newer board with an on-board boost converter is in development.
Can I use this as a fishfinder on my boat?
Technically yes — the Baltic tests show fish arcs — but the interface is a raw echogram, not a polished fishfinder display. If you want depth, bottom hardness and fish targets in a single screen, a commercial unit like a Garmin Striker is easier. This is for people who want to see and log the raw sonar data.
What is the maximum depth?
The README reports at least 50 m tested in water, with a 38 m range test published. Theoretical range depends on transducer power, frequency and gain settings — lower frequency goes deeper but with less resolution.
Do I need a licence to operate this in water?
In most countries, passive sonar (listening only) needs no licence, but active sonar (transmitting pulses) may be regulated near marine protected areas or military zones. Check local rules — most recreational echo sounders are permitted, but this is technically a transmitter.
Can I use this for side-scan or imaging sonar?
Mostly no. Open Echo is a single-channel echosounder that looks straight down. The README does list a Lowrance Tripleshot side-scan transducer as tested, but you get raw single-channel data, not a finished side-scan image.
What frequency transducer should I buy?
The README tested 150 kHz for the Baltic scans. Lower frequency (40-80 kHz) penetrates deeper but with less detail; higher frequency (200-1000 kHz) gives finer resolution but shorter range. For general bathymetry, 150-200 kHz is a good compromise.
Community builds
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Discussion1
FROM THE COMPAREE TEAM
The Baltic Sea tests used a 150 kHz in-hull transducer driven at 15-20 V from an MT3608 boost converter, with scans showing a 38 m range test, seabed types and fish. If you were mounting this on a boat or ROV, what depth range and frequency would you target first?
Jan Neumann
Jan Neumann (ORCID 0009-0003-9829-8959) wrote almost all of Open Echo himself, with a single outside contributor in the commit history. The project began in May 2024, has published real test data from the Baltic Sea along with six videos, and is still actively maintained.
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DISCLAIMER
- Comparee is not the author of the projects featured here. All rights to each project belong to its creator — every page links to the original source, and we never host creators’ files.
- Information is provided without warranty and may become outdated as projects evolve. Prices are indicative bands only — always check the creator’s parts list for current costs.
- Building and operating any project is at your own responsibility. Protective equipment, safe workshop practice and compliance with local regulations are the builder’s responsibility.
CompareeTEAM1mo agoedited
Practical notes from our verification: the repository has no licence file, which is unusual for a project this mature, so do not assume commercial rights until the author clarifies. You can buy the shield fully assembled from Elecrow, order it from the author in Germany or the EU, or have it made from the KiCad files, Gerbers and the BOM in the production folder. The Python interface runs from source rather than as an installer, and there is also a web interface and an NMEA firmware for sending depth straight to marine electronics or a Pixhawk. The single biggest decision is transducer choice and mounting: the README lists tested options from 40 kHz up to 1000 kHz with ratings and prices, but every hull and enclosure is different. Range is not automatic either. The default capture covers roughly 18 m in water, and for deeper water you add delays in the code and tune the drive voltage. Questions go to the project's Discord. Correction (4 October 2026): we re-checked this page line by line against the project's own repository, documentation and videos, and fixed errors in earlier versions.