Pyssel

Updated 2025-10-15 for Trixie ! The purpose of a watchdog timer(WD) is very well described here but a more practical answer is; If your Raspberry Pi(RPi) "freezes", or hangs, it will automagically reboot within a very short time. This is made with a combination of hardware and software which is all ready available, on the RPi, and just have to be enabled. After some hours Googling and testing these are my findings !

  I really like the products on AliExpress and Alibaba, but in most cases the documentation is very simple and to short. So when I bought a combined tracker and a burglar alarm, to our boat, I really tried to get the best. One important thing was that, if possible, getting a lifetime app support. The purchase went well and 14 days later it arrived in Sweden.

Updated 2025-06-28 ! Are You searching for a solution where You want to create graphs and gauges from SignalK(SK) data ? Use NodeRed(NR), installed as a SK plugin , with the standard dashboard and it's easy to create info as seen in the picture. And this is without a database as InfluxDB and tools like Grafana. You use the WebSocket interface , or SK subscribe nodes, to subscribe to changes in data from the SK server. 

Updated 2025-06-23 ! I have got some questions installing, just,  Signal K (SK) so will do a summary with links. Signal K is the hub to receive data, from different devices in different data formats, and send it on to different equipment, or databases, in different formats. Most common for standard marine equipment are the old NMEA 0183 and the newer NMEA 2000 protocol which is also handled.  Besides the SK "hub" function developers  have  created  plugins  for different purposes. This is due to that  SK is open-source ! Sharing is caring ! In this post you can check the devices I'm using connected to the SK server and also my setup.

Updated 2025-06-10 ! The sea water pump, labeled 3589907 and replaced by 21380890, was leaking a little so a change of seal was necessary. Numbers below refers to the explode view. Detach the generator belt from the pump pulley and the 2 hoses from the pump. Unscrew the water pump, 4 scews, from the engine block. Remove the cover, 7, from the pump. Pull out the impeller, 6. Remove the cam, 4, by unscrewing screw 18. Remove the washer, 22. Remove the lock ring 14 and washer 21. With a pliers try to remove the seal 8.

Updated 2025-02-15 ! Empty the fresh water system with compressed air !! One of the things, when You head back to land with the boat, is to empty the fresh water system. I have got several instructions/tips over the years but the best advise I got is to empty the pipework with compressed air. Some time ago I bought a handy Stanely compressor. Just below 10 Kg in weight including a 6 liter tank. Nice for smaller works

Updated 2025-01-04 DMI is the Danish Meteorological Institute and the   Open Data API provides free and open access to DMI’s data.They are covering a pretty big area not just Denmark . I'm maintaining the weather station for Domstens yacht club and have become really interested in weather "issues". The actual use case for me is that I have to change the mooring, of our boat, if the water level exceeds 60 cm from normal.   For several years I have been searching for a free forecast API so I can get an early warning when the water level rises. Node-Red is used.

Updated 2024-10-25 I found this amazing application,   AIS-catcher , just scrolling around on Youtube and  it includes "all" you need for an AIS receiver staying ashore or installed on a boat. It is compatible with a wide range of Software Defined Radios (SDRs). These include RTL-SDR dongles (such as the ShipXplorer AIS dongle and RTL SDR Blog v4), AirSpy (Mini/R2/HF+), HackRF, SDRPlay, SoapySDR, and file/network input (ZMQ/RTL-TCP/SpyServer). 

Updated 2024-08-30 !  !! Another SW solution is available for RPi 5 here !  using the same HW. Thanks to Thomas, (the guy with the nice marine interface board ) ,  it's now possible  to decode, one way, the SeaTalk1(ST1) sentences in a pretty simple way. You just  use OpenPlotter(OP) and/or SignalK(SK) and an  Optocoupler . The thing that made it, is that Thomas   has released a "how to" and  Python source code , that will read the data from a GPIO pin on the Raspberry Pi, (RPi), and format it so the standard parser in SignalK can translate it to SignalK delta format. It is then  available as NMEA 0183. It's even possible to send the data in to a NMEA 2000 network, with a proper hardware interface.

Updated 2024-07-08 To get information from the NMEA 2000(N2K) network, to the RPi, I have been using  Actisense NGT-1 , for a long time,  and later also the  Yacht Devices YDWG 02  but now it was time for a Raspberry Pi(RPi) CAN hat(CH) from Waveshare(WS). WS have 3 different models but I picked the 2 channel isolated one . It's recommended to use an isolated one which also is demanded for those interfaces which can be approved by the N2K group.

Updated 2024-06-30 ! OpenPlotter(OP), a Boat Navigation application, is really a nice and simple installation of OpenPlotter (OP) OpenCPN (OC) SignalK (SK)  and other supporting applications for Your boat. An overall information about the OP package is found  here   and you can watch the OP v4 progress  here .

Im using NodeRed together with  Speedtest by Ookla  but just the other day it wasn't showing the right data so it was time for "Bredbandskollen", the command line version. Bredbandskollen has always been a reliable source when testing internet speed.  I'm using their WEB-site and the iPhone app and it have always worked very well. This post will show how to plot data in a graph according to the picture.

Just the other day the backlight for our classic Raymarine E 120, Navigator(MFD), stopped working. It's from 2006 so I'm not surprised that things happen. You may wonder why we keep it instead of buying a new one but the thing is that we have 2 installed together with a well functioning radar so buying new stuff will be a hefty price tag. After some Googling I found out that the backlight is produced by a CCFL , a type of neon light, and can give up after some years. The Googling also gave some tips how to change to a LED backlight. The picture above is showing a test with a short LED light strip to verify the solution, with dimming working, and checking the health of the MFD.

Updated 2024-05-03 ! In Signal K (SK) there are 2 applications, in SK appstore, that can handle charts Freeboard SK (FSK) Tuktuk Chart Plotter (TT) FSK, preinstalled, uses the OpenSeaMap charts(OSC)  when you are online.  If you want to use offline charts or other chart resources you have to install " @signalk/charts-plugin "(CP)

Updated 2024-03-01 ! OpenPlotter(OP), a Boat Navigation application, is really a nice and simple installation of OpenPlotter (OP) OpenCPN (OC) SignalK (SK)  and other supporting applications for Your boat. An overall information about the OP package is found here . Install guide for the new stable OP, version 4, is found here .

Updated 2024-02-08 GRIB is a data format , used for meteorology, to store historical and forecast weather data.  The use case for me was analyzing forecast data, from GRIB files, so an early warning could be rised before a high water level or coming storm appears. This could then be used at our weather site . There are several applications , also ones that visualizes the data, but this post will handle how to extract data from files using command line. Forecast without GRIB files ? Check this API for Europe.

Updated 2024-01-20 !! OK with Bookworm !! This post covers the setup for a AIS, dual channel , receiver for Raspberry Pi(RPi) with systemd autostart. I'm using the RTL-SDR dongle V3 with almost zero temperature drift or the even better  NooElec NESDR Nano 3 AIS posts with charts/maps OpenSeaMap and dispatcher   OpenStreetMap and dispatcher Improve receiving range? Calibrate ! Instructions in this post The best AIS application ?  is found here  !

Updated 2023-12-05 !! OK, with Bookworm (32/64 bit) !! To optimize the reception with SDR:s, Software Defined Radios, it is important to receive on the proper frequency. Due to variations in production there could be deviations. The calibration could be done against standard GSM transmitters which are providing a stable reference frequency. Another way is found in the AIS-catcher application and use the information supplied in the graphs "Frequency Shift". 

Updated 2023-11-09 ! The AIS posts on this blog have been very popular so this post will be a follow up which will enable You to show AIS targets, including AtoN:s, on  OpenSeaMap , (OSM), together with buoys and beacons. The application showing the map is SignalK , (SK) a OpenSource project for marine use.  With the " ais-forwarder " plugin you could send/dispatch the NMEA AIS data to   Marinetraffic  or  Vesselfinder . Another   AIS-dispatcher . The best AIS application ? is found here !

Updated 2023-11-06 ! I have searched for a solution transmitting the NMEA data, from the navigation network, via WiFi, to for example  iSailor  or other Tablet/Phone applications. Most of these applications just accepts NMEA0183(N1) but many boats are also using SeaTalk 1(ST1) and NMEA2000(N2K). This post will cover, kept compact, my best findings covering both a DIY and a commercial approach to handle the different protocols.