DIY keel sensor


Gerry from the Sailing Forums built a keel sensor to show the extended depth of a liftable keel. In addition to the keel depth, the heel is also displayed. The keel depth is measured using an ultrasonic sensor. For this purpose, the sensor is mounted inside the keel box and looks down on the lowered keel. The measurement data can be transmitted via WLAN, for example… Continue reading

MAIANA ™: The Open Source AIS Transponder

Fig.MAIANA AIS transponder transmitting and receiving part with fixed antenna (Open Marine)

Peter Antypas self-built an AIS class B receiver / transmitter and presented it on Github:


The device combines the following functions:

  • AIS class B receiver / transmitter
  • 161.975 MHz (channel 87B), 162.025 MHz (channel 88B)
  • 2W transmission power
  • Silicon Labs 4463 transceiver ICs
  • STM32L412 microcontroller 80MHz
  • GPS Quectel L70R module, ceramic SMD antenna (for your own location transmission)
  • 3.3V UART output at 38.4Kbps
  • NMEA0183 data telegrams
  • Update rate 1 Hz
  • 12V / 30 mA
  • Disclosure of construction documents and the Software on Github

The AIS transponder consists of a transmitting and receiving part with a permanently attached antenna, which is connected to an adapter box via a shielded cable.… Continue reading

DIY water treatment


Caused by the corona crisis, many sailors could not use sanitary facilities and access clean water for showering or washing dishes. It was created in a Discussion in the sailing forum from PePeSail a solution for the water treatment of surface fresh water as found in inland areas in lakes or rivers. On the homepage he introduced the system in more detail.… Continue reading

LoRa boat monitor

First of all, a few important notes that you should definitely pay attention to.

The LoRa boat monitor is used to monitor the boat when you are away. Various measured values are transmitted continuously at freely adjustable time intervals via LoRa radio technology (long range) to the LoRaWAN forwarded and recorded. The data is sent from the TTN server V3 (The Thinks Network) received and cached in Ireland for Europe and then to Ubidots forwarded as web frontend.… Continue reading

DIY Tiller Pilot

  • Restart 08/2018
  • other Projects
  • Standby since 09/2019
  • currently no further activities, as problems of the sensor calibration have not been solved satisfactorily
  • current approach distribution:
    • AHRS 9-axis digital sensor (compass, gyro, acceleration sensor)
    • ESP32 controller unit (possibly a combination of fuzzy control / classic control algorithms)
    • Actuator industrial linear unit
  • Status: Tests on the position sensor AHRS (Altitude and Heading Reference Sensor)
  • Most projects are still in the concept development phase
  • There are currently three projects working on the topic: Continue reading

DIY board controller

The on-board controller monitors and controls the energy system of a yacht

Development goals

  • Increase in operational safety
  • Increase in the battery life
  • Fast charging of the batteries

Increase in operational safety

By displaying the accumulator states, the operator is informed at all times about the availability of the accumulator system. An age-related defect in the accumulator can be diagnosed by a constant decrease in capacity, so replacing the accumulator should be planned in good time.… Continue reading

DIY remote control for Seatalk autopilot

First of all, a few important notes that you should definitely pay attention to.

  • OpenSource Seatalk radio remote control for Raymarine autopilots
  • Basis: Arduino ProMicro and 433MHz radio module
  • Simple 433MHz 4-channel radio transmitter can be used
  • Plus / minus 1 and plus / minus 10 degree steps
  • Can also be combined with an OLED display (e.g. for wind display)
  • Simple solderability through the use of conventional components in through-hole technology
  • Programming with Arduino IDE
  • Costs (board and components): approx.
... Continue reading

DIY engine diagnostics

First of all, a few important notes that you should definitely pay attention to.

  • Retrofitting for all motor types, as independent sensors are used
  • Use of cheap sensors
  • Measurements of various engine parameters
  • Flow rate cooling water (impulse, YF-S201B)
  • Temperature cooling circuits (1Wire, DS18B20)
  • Engine compartment temperature (1Wire, DS18B20)
  • Engine RPM (Pulse, GP2A26 Sharp)
  • Output Shaft Speed (Pulse, GP2A26 Sharp)
  • Tank level via pressure sensor
  • Engine operating hours (via speed detection)
  • Power supply via 12V on-board network
  • Data processing with ESP8266
  • Data transfer via WLAN
  • Data protocol NMEA0183, partly with customer-specific telegrams
  • Data display via OpenPlotter
  • Simple web front end for operation and display via mobile phone
  • Waterproof case
  • Installation location in the engine compartment for short cables
  • All sensors connected by cable
  • Price less than 120 euros for material
  • Current Circuit diagram
  • Board is with Aisler orderable
  • Current software: Source code, Binary file Continue reading