Multifunction display OBP 60

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

Display in action

open boat projects LIVE:
Video presentation in German on the OBP 60 multifunctional display (45min presentation, 30min discussion)

After we have dealt with the M5Stack as a multifunction display in 2019 and could show and were able to show some applications at Boot 2020, we are taking a new approach to a new multifunction display here. The M5Stack was not bad, but was subject to certain limitations for which some marine applications were not possible.

The disadvantages of the M5Stack include:

  • Display that is too small and not suitable for sunlight
  • Only 3 control buttons
  • Not waterproof
  • Too low battery power for standalone applications

However, some useful applications could be implemented:

The M5Stack is very flexible to use and well documented, but could not convince in the large number of marine applications. Following the widely used and popular ST60 series of instruments from Raymarine, a new attempt was made to build a more suitable multifunction display. In terms of housing dimensions, the new multifunction display is identical to the ST60 device series. Thus, the multifunction display can serve as a direct replacement for old and defective devices. By supporting old bus systems like NMEA0183 and SeaTalk, a bridge to the new world with NMEA2000 is provided, so that older systems can still be operated. The WLAN capability also allows to go completely new ways in signal transmission with connection e.g. to SignalK. Commercially there is a good selection of multifunction displays, but they are very limited in terms of expandability and adaptability to individual needs. You can only do things with the multifunction display for which the manufacturer has provided functions. Unfortunately, nothing can be modified or extended by the user. The goal of the whole development should be an open system where the user has access to all functions of the multifunctional display and can implement his own ideas by adapting the software and additional hardware. The standard electronics is designed in such a way that in the future it will be possible to replace it by other housings of other device series. Thus, maximum flexibility and openness is given.

Currently, the project is still in development.


In the design of the new display, emphasis was placed on the following points:

  • Standard size for a multifunctional display (110 x 110 mm)
  • Suitable for daylight
  • Waterproof
  • 6 keys
  • Support of the following bus systems:
    • NMEA0183
    • NMEA2000
    • SeaTalk
    • I2C
    • 1Wire
  • Low power consumption
  • WiFi-capable
  • Bluetooth-capable
  • Expandability via I2C bus and 1Wire
  • Hardware extensions via I / O port
  • Autarkic usable with battery pack for several days
  • Standard electronics for compatibility with other device series (NASA, Clipper, Navman, etc...)
  • Freely designable housing and therefore adaptable to other device series
  • Openness (OpenSource, OpenHardware)
  • Rebuildability with hobby means due to simple construction
  • Use of ready-made electronic modules
  • Adaptability to different needs
  • Software library for the Arduino IDE (similar to M5Stack)
  • Software updates via micro USB and WiFi

Video of the construction of the multifunctional display

Video to PCB


Specifically, the multifunction display was implemented with the following components and the following specification:

  • NodeMCU-32S as CPU unit
  • E-Ink display (400 x 300 pixels, 4.2″, suitable for daylight)
  • SeaTalk (full duplex)
  • NMEA 0183 (RX or TX, configurable)
  • SeaTalk (full duplex)
  • I2C
  • 1Wire
  • 8x I / O expansion port (internal)
  • 6x touch keys (swipe capable)
  • 2x digital out (12V, 4A)
  • 2x digital in (12V)
  • 2x Analog In (tank sensor 0...180 Ohm, battery etc.)
  • Battery monitor (12V voltage measurement)
  • Acoustic signal generator (buzzer)
  • Optical signal generator (red LED)
  • LED display lighting (red LEDs)
  • BME280 (temperature, air pressure, humidity)
  • GPS receiver (NEO-6M with internal mini GPS antenna)
  • WiFi 2.4GHz (HTTP, TCP)
  • Bluetooth
  • Power consumption approx. 2W (without backlight)
  • Power consumption approx. 3W (with backlight)
  • Battery deep discharge protection <9.0V (Deep Sleep, 0.2W)
  • Low Power Mode (Deep Sleep with WeakUp 0.2W, 15mA @ 12V)
  • Connections for optional LiPo battery pack (50Wh, approx. 24h self-sufficient)
  • Extension connections 8x digital IO, RX, TX, I2C, 5V 0.5A, GND

The next figure shows a schematic of the function blocks and their interconnection.

Fig. Functional diagram

The board is equipped with various SMD components and will therefore no longer be solderable without further ado. Some electronic modules can be assembled individually ( E-Ink-Display, NodeMCU-32S, BME280, GPS) The board will be offered for sale later fully assembled without electronic modules.

Fig. Front side of the circuit board

Fig. Rear of the circuit board


Fig. Electronics front

Fig. Electronics with e-ink display

Fig. Electronics rear

Fig. Front housing with display disc and contact springs for keyboard

Fig. Rear of the MFD

Circuit diagram

Possible uses

In principle, the following things could be realized with the multifunction display:

  • Instrument display of bus data from NMEA2000, NMEA0183, SeaTalk, WiFi
  • Gateway between NMEA2000, NMEA0183 and SeaTalk
  • Export of all sensor data via WiFi for tablets
  • SignalK connection
  • Weather display with weather history (BME280)
  • GPS display
  • Current position display in sea chart (with internet connection via OpenSeaMap)
  • Wind display (true wind)
  • Simple GPS autopilot (with DC motor as actuator)
  • Anchor watch
  • Battery monitor (with I2C current sensor also charge monitor)
  • Solar monitor (with I2C current sensor)
  • Motor diagnostics (temperature, speed)
  • Speedometer (with common pulse sensor)
  • AIS display graphically (with AIS receiver)
  • Info display for email, messenger services
  • Display for clock (UTC, local time), date, sunrise and sunset
  • Sailing timer (distance and time to start line)
  • Watch timer
  • Next Treckpoint indicator with XTR and audible alarm
  • Tank level indicator
  • Bilge monitoring with pump control
  • Alarm system with notification via WLAN including GPS tracker
  • Weather forecast (with internet connection)
  • Boat automation (with Sonoff components)
  • Reception of commands from a Bluetooth remote control with
  • Receiving Bluetooth wind sensor signals from Raymarine (if the signals can be decoded)
  • Control of audio media players (DLNA)
  • Firmware update via WiFi
  • and, and, and ....

In order to realize the possible applications, however, software is required that still has to be programmed and transferred to the multifunction display in the form of firmware. However, the firmware will not be able to implement all functions at the same time. Depending on the application, a suitable firmware is loaded onto the device via USB or WiFi connection and can then implement one or more functions. We hope that the multifunction display will find a lot of interest and that some will participate in the software development.

Current status

In the meantime, the first firmware has now been implemented. Thanks to the great software project NMEA2000 gateways from Andreas I was able to use core software that already covers many parts that I also needed for my firmware. The NMEA2000 gateway contains a complete gateway for converting the data between NMEA2000 and NMEA0183 and supports the transmission layers CAN bus, RS485, RS422, TCP and USB serial. The core software was written by Andreas for ESP32 microcontrollers in C ++ and was originally for one M5Stack Atom thought. Since the multifunction display also uses an ESP32 as a CPU, I decided to program extensions for Andreas Gateway software. This allows the hardware functionalities of the multifunction display to be used and data to be displayed. Andreas had to add various extensions and software functionalities in his software for me. Within a short time, a very useful firmware for the multifunction display was created with the following functionality:

  • Instrument display of bus data from NMEA2000, NMEA0183, WiFi, USB
  • Gateway between NMEA2000, NMEA0183
  • Generation of any user-defined XDR data for NMEA0183
  • WiFi access point for configuration
  • Web user interface (password protected)
  • Status line in the display
  • Red background lighting that can be switched on and off
  • Simple dashboard for displaying and diagnosing bus data
  • Firmware update via WiFi and USB
  • Export of all sensor data via WiFi for tablets
  • Weather display (BME280)
  • GPS display
  • Simple battery monitor (voltage display)

Currently, 4 display pages can be parameterized through the web configuration, which can be called up via swipe gestures. There are different types of display pages defined as follows:

  • Freely configurable display pages
    • On-value display
    • Two-value display
    • Three value display
    • Four-value display
  • Non-configurable display pages
    • Battery voltage indicator
    • True Wind with instrument display

All available bus data can then be brought to the display pages. The current firmware can be found at GitHub:

A detailed description of how to install the firmware is in the project for NMEA2000 gateway to find.





One of the biggest hurdles was the lighting of the e-ink display for night operation. It can only be illuminated from the front and requires special front glass that deflects the light coupled into the side via LEDs onto the e-ink display by 90 °. Making it yourself as a maker was not that easy. Industrially manufactured e-ink displays with lighting use front glasses that are microstructured. Such glasses cannot be bought in normal specialist shops. The aim was to apply the microstructuring yourself with the help of a laser. Laser devices that can be bought for makers do not have such a high resolution and we had to make some compromises with regard to efficiency and visibility. The best results came after many attempts a dithered laser point laser with an introduced point density gradient. A laser point is a disruptive body on the surface of the windshield, which deflects the light in all directions. The efficiency is not particularly good, since the light cannot be deflected in a directional manner and is only emitted from all sides in the room, so that only a small part of the scattered light can be used. We were able to achieve a minimum point size of approx. 200 µm with the laser. To create a gradient, we used a graphics program and created a gray level wedge with a 0… 12% gray component and then dithered it. The image resolution was 600 dpi. We used this image template for the laser process. Due to the high number of points, the laser process with a laser with XY traversing unit took a good 45 minutes, as the laser had to build up the image line by line. The result is impressive. The light is deflected as desired onto the surface of the e-ink display.

Fig.Laser points under the microscope (1% gray portion)

Fig .: Dithered image template for the laser process

Fig. E-Ink front lighting

A 3 mm thick Plexiglas pane is used as the front pane. The laser-structured side is on the outside. Alternatively, you can also use special Plexiglas panes for the advertising industry. This plexiglass is used to shine through advertising posters from behind and is often used in showcases or for illuminated pictures. This special Plexiglas is transparent and you can couple light into the front edge of the pane from the side, which is then scattered. The entire volume of the plexiglass acts as a diffuser. The Röhm company produces such special glasses under the name Plexiglas LED plate 0E010SM (4 mm). However, the lighting results are not as good as with the laser-structured windshield. The contrast of the illuminated display is too low and the picture is noisy.

Fig. Left laser-structured disk, right Röhm disk

In addition to protecting and lighting, the plexiglass pane has another task. It should protect the e-ink display from UV radiation (UVB, UVC) so that the display does not go blind. According to the specification, the e-ink display must not be exposed to direct sunlight or UV light. The reason for this is that the small pre-charged color balls in the display lose their charge due to UV radiation and can then no longer be aligned. Ordinary plexiglass has the useful property of suppressing UV light.

Fig. UV transmission of different glasses (2nd from plexiglass)


Fig.Multifunctional display with loaded demo nautical chart

Fig. Allen countersunk head screws as touch buttons

Fig. Viton seal as moisture protection

Fig.Raymarine standard mountings

Fig. Closing seal opposite the cockpit wall with 2mm thick Mosgummi

Fig. Total thickness corresponds to the original

Fig. 3D printing process

Fig. 3D front housing


Fig. Front housing with e-ink display


Fig. Illuminated e-ink display

IR remote

After Christian at Boot 2020 in connection with his plotter Had introduced a bluetooth remote control there is now a new IR remote control. It had been shown that Bluetooth is not that suitable for a remote control after all, since there were significant problems under Linux with the connection establishment and the remote control did not work as expected. The change to infrared enables the use of inexpensive electronic components in connection with a long running time, since no communication has to be continuously maintained with the IR remote control. The remote control works exactly like the remote controls in the home entertainment area. The only difference is that the remote control is waterproof. In order to simplify the implementation under Linux or in microcontroller environments, an intelligent one was added Receiver with a microcontroller that converts the received signals to I2C.

The remote control has the following specifications:

  • IR signals for data transmission at 36kHz
  • 14 keys with freely definable special functions
  • 2 powerful IR diodes
  • CR2032 head cell as power source
  • Inexpensive hardware with standard components
  • Waterproof, robust housing with hand cord
  • 2 different remote controls can be used simultaneously through coding
  • IR receiver with microcontroller for decoding the signals
  • Forwarding of received signals via I2C bus
  • Dimensions: (L x W x H) 140 x 45 x 25 mm
  • Weight: approx 100g
  • Costs. approx. 35 euros
  • Remote control wiring diagram
  • Circuit diagram for receiver

Possible applications:

  • Remote control for
    • plotter
    • Autopilot
    • Multifunction display
    • Audio
    • light
    • Automation


I2C modules by Horter & Kalb

The I2CModules of the Horter company (LxW 65x45mm) can be used for boat automation because they can be connected to any microcontroller and the Rasperry Pi. The I2C bus is actually intended for communication between ICs on a circuit board. But there are also numerous Extensions with which the bus signals can be amplified and electrically isolated so that further distances can be bridged with shielded cables of up to 50m. The I2C modules from Horter are designed so that they can be used in Support frame can be installed for fastening. Alternatively, they can also be mounted on top hat rails. At Horter, up to 28 different DIN rail modules and other modules can be purchased. Most of the modules are offered as kits with prices between 10 and 30 euros. Due to the large number of modules, different complex applications can be implemented.

The following modules would be of interest for boat automation:

  • I2C digital input module 8x 0… 24V with optocoupler
  • I2C digital output module 8x 0… 24V 1A with optocoupler
  • I2C analog input module 4x 0… 2V, 0… 10V, +/- 10V, 20mA (each input can be configured individually), 18 bit resolution
  • I2C analog output module 4x 0… 10V, 40 mA, short-circuit proof, 10 bit resolution
  • I2C 433MHz radio transmitter (to control wireless switch boxes)
  • 5V / 3A power supply for I2C modules
  • I2C repeater with level adjustment for Raspi 2/3/4
  • I2C module for Arduino Pro Micro
  • I2C module for Wemos D1 mini (ESP8266)
  • Supply voltage input 7V… 40V, output voltage 5V / 3A

This can do some nice things like:

  • Boat automation with Arduino Pro Micro module
  • Boat automation with ESP8266 and ESP32 via WLAN
  • Boat automation with Raspi and NodeRed
  • Extensions for the Marine Control Server (MCS)
  • Signal acquisition and output for SignalK (a corresponding plug-in would still have to be programmed)
  • Extension modules for the Multifunction display
  • Control of analog pointer instruments via analog outputs for historical boats
  • and and and….

DIY keel sensor


Gerry from the sailing forum has built a keel sensor to show the depth of a recoverable keel. In addition to the keel depth, the heel is also displayed. The keel depth is measured with the help of an ultrasonic sensor. For this purpose, the sensor is attached inside the keel box and looks at the lowered keel from above. The measurement data can be displayed via WLAN, for example in a mobile phone browser. The following components were used for the keel sensor:

  • ESP32 NodeMCU (WLAN-enabled microcontroller)
  • MB1043 HRLV-MaxSonar-EZ4 (ultrasonic sensor with narrow beam)
  • MMA8452 (3-axis gyro sensor for inclination display )
  • D24V10F5 (voltage regulator)

The whole thing can be set up quite easily on a breadboard. Circuit diagram tells you more about the wiring.

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. The transmitting and receiving part receives and decodes the AIS signals and transmits them as NMEA0183 data stream with 3.3V voltage level to the adapter box, which can forward the NMEA0183 data stream in three different ways:

  • NMEA0183 USB output for PC or Raspi
  • NMEA0183 RS422
  • NMEA2000

There is a separate adapter box for the respective output type. A normal shielded CAT5 network cable with RJ45 plugs is used as the connection cable. In addition to receiving AIS signals, MAIANA can also send AIS signals. Since the device has no CE certification and radio approval for AIS operation, it may only be used in receiving mode in Europe. In principle, transmission is also possible, which can be switched on via a switch on the adapter box.

The AIS transponder is sold through OpenMarine. On the website, the buyer is advised that he is buying a device that is not CE certified and approved. It is the responsibility of the buyer to comply with the respective approvals in his area of use. Finally, the device must not interfere with or impair the AIS data traffic when transmitting. Otherwise it would have fatal consequences. In Europe, the reception of AIS signals is not a problem, whereas the transmission operation requires a permit. According to Peter Anypas, the legal situation in the USA is different. There you can use devices you have built yourself in transmission mode if the transmission power is limited



Fig.MAIANA AIS transponder transmitting and receiving part

Fig.Transmit and receive part (Open Marine)

(Open Marine)


Fig.Adapter board USB version (Open Marine)

Fig.Adapter USB version (Open Marine)

Fig.Adapter RS422 version (Open Marine)

Fig.Adapter CAN version (Open Marine)

Fig.AIS transponder behind radar device (Open Marine)

Fig.MAIANA AIS transponder rear mounting (Open Marine)

DIY electric drive 3 kW

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

3 kW electric drive for a 25-person sailing boat Make 25 (all pictures from

PePeSail from the Segeln-Forum approached us and pointed out his DIY project to install an electric drive in a 25 foot sailing boat and asked whether we would like to publish it here. In the project, a built-in diesel was exchanged for a 3 kW electric drive. The renovation was done on our own. To do this, the electric motor had to be coupled to a new cardan shaft system via a gearbox. Some lamination work also had to be carried out in the boat hull to accommodate the shaft bearings. The whole project is described in detail here:

The project started in the Segler-Forum. Many fundamental considerations and questions about e-propulsion on boats were also discussed there:

Here is a video about the running electric drive:

Technical marginal data for the project:

  • 3 kW brushless e-motor 48V with electronic control
  • Toothed belt drive
  • 4x 12V 60AH LiFePo4 batteries
  • 2x 18A charge regulator
  • Cardan shaft with through bearing



Shaft system and shaft passage

Battery box 4x 12V 60Ah LiFePo4 batteries with balancer

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. The aim should be to use simple means to treat the surface fresh water so that it can be used for simple applications. To get straight to the point, drinking water cannot be obtained with it, as biological residues cannot be removed to a sufficient extent. The single-stage activated carbon filter system draws in seawater with an electric pump and pushes it through an activated carbon filter. The filter system consists of only a few parts and can be easily accommodated inside the boat. The system has the following properties:

  • Activated carbon filter 0.3 µm to remove
    • chlorine
    • lime
    • Pesticides
    • Insecticides
    • Oil, gasoline, solvents
    • Taste impairment
    • Odor nuisance
  • Electric submersible pump with filter performance of 4 l / min
  • Simple hose system
  • The activated carbon filter does not protect against legionella
  • There is no drinking water

The filter could also be used to clean the bunkered drinking water, as the quality of the drinking water at jetties is often not too good.

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 it is absent. Various measured values are continuously recorded at freely adjustable time intervals and transferred to the LoRaWAN forwarded. The data is from the TTN server (The Thinks Network) received in Amsterdam and cached and then sent to Ubidots forwarded as a web frontend. The data transmission is secured by encryption up to Ubidots. The measured data is displayed in Ubidots and various notifications can be sent by email when measured values are exceeded. There are a large number of LoRa gateways which can receive the sent measurement data and forward it to the TTN server. Many LoRa gateways are run by private individuals on a non-profit basis. Anyone who wants can operate their own gateway and make it available to the general public. The radio technology uses the license-free frequency range around 868 MHz and uses a special transmission technology (chirp) to achieve large ranges of up to 50 km at low data rates. The ranges depend on the type of transmission, the antenna height and the environment. In built-up areas such as cities, typical ranges of 1… 4 km are possible. In open environments such as lakes and the sea, up to 50 km can be reached. There are no costs for data transmission when sending LoRa telegrams. This is the big difference to other long range transmission technologies like SIGFOX and mobile data networks such as 3G / 4G / 5G. If no LoRa gateway is within range, a simple 1-channel or 3-channel LoRa gateway can be set up with the same board. Only a few components are then left out and a different firmware used. Alternatively, the measured values can also be sent directly to Ubidots via WLAN, provided that a WLAN is within range.

Image: LoRa data transmission Semtech GmbH

Image: Block diagram LoRa boat monitor

The LoRa boat monitor has the following functions:

  • 10… 32V supply voltage
  • 1.2W power consumption
  • LoRa transmitter and receiver with OLED display
  • 868 MHz, SF7… SF12, 100 mW transmission power
  • Dynamic spreeding factor adjustable SF7… FS10
  • Supports channels 0… 7 dynamic and fixed
  • Data transfer rate: 0.3 to 50 kbit / s
  • Max. Telegram length for user data: 200 bytes
  • Range: built-up area 1… 4km, open area up to 50km
  • LoRa transmission interval 30s… 2.1h
  • One-channel, three-channel and eight-channel modes can be set
  • Feeding the data into The Thinks Network (TTN)
  • Parameterization of the LoRa boat monitor possible via return channel (channel, SF, transmission interval, relay)
  • WLAN (2.4 GHz) for alternative data transmission
  • Web interface for operation
  • Firmware update possible via WLAN and Internet
  • GPS sensor for geographic location coordinates
  • BME280 for measuring temperature, humidity and air pressure
  • 1x battery voltage measurement (0… 32V service battery)
  • 1x potential-free alarm contact eg for bilge and door monitoring
  • 2x tank sensors (0 ... 180 Ohm) with percentage display
  • Calibratable tank and voltage sensors
  • 1x Reais output for potential-free switching of loads with specified time (5min ... 21h) up to 3A (12V or 230V)
  • 2x 1Wire connection for temperature sensors DS18B20 for battery monitoring and refrigerator
  • Monitoring and alerting via Ubidots web frontend
  • Alerting by e-mail if limit values are exceeded via Ubidots
  • Automatic data storage for the last 31 days at Ubidots
  • Use of cheap embedded modules
  • No SMD components on the board
  • Board can be ordered here:
  • Android app: LoRa_Boatmonitor_1.apk

Fig .: Main menu

Fig .: LoRa info

Fig .: Sensor info


LoRa 32 Heltec radio module as the basis

LoRa gateway

Ubidot's web frontend with measured values and geodata

Circuit board for the boat monitor

Equipped panels (left LoRa boat monitor, right LoRa gateway)

LoRa boat monitor

Lora gateway


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:

Concept 1 with Raspi as controller and external sensor network

Concept 2 with ESP32 as controller

Concept 3 self-sufficient compact tiller pilot

Prototype AHRS GY953 with ESP8266

Data of the prototype AHRS in OpenPlotter


Functional principle of the fusion with complementary filters

Rudder position sensor made from 3D printed parts by Malte

Prototype with GPS sensor from Malte

Linear actuator disassembled