Raspberry, edit config or add files before boot

The actual use case was that I have a Raspberry Pi(RPi) sourcing Vesselfinder with AIS data from nearby. I wanted to change/test a new configuration but on the other hand I didn't want to take the RPi down, during a longer period, since it's an online service.

So the solution was to make a bootable clone of the actual application and test with a second RPi. The major obstacle was that I then would have 2 hosts, with the same hostname, which will mess up the local network.

So how to change the host name on the cloned SD card before I'm using it in the second RPi ?

Another post on how to read and write Linux drives with Windows/MacOS

Davis weather station, WeatherLink, PHP

Updated 2021-12-05 !

In the harbour we are using a Davis weather station, Vantage Pro2, as our PWS(Private Weather Station).

If you like to display the data, online on the web, you can use the Davis service, Weatherlink(WL) where you register an account. 

Another way is to retrieve the weather data as XML or JSON, from the Weatherlink web-site, and use it in your own application (open source!).

Another approach with NodeRed could be find here.

Raspberry, restart network, or reboot, at ping failure

Using a Raspberry Pi Zero(RPi), with wifi, I sometimes have problem that the WiFi connection is lost. This is due to that, at our boat, we are using the Teltonika RUT 240 router. The router just have one receiver/transmitter, LAN and WAN WiFi are shared, and in some use cases the WiFi will temporarily be disconnected. To restart the WiFi quick the following solution is used.

This post will cover a solution, a bash script, with inspiration from this blogpost, but with some fine tuning. 😉
 

Another way could be using the watchdog function, described here, with reboot.

SIGNL4, automated alerting with free mobile app

I'm involved in several projects where you, as quick as possible, want to get an alert if anything fails. After a lot of Googling I found SIGNL4.

They have several ways to create an alert, can involve a team, have a nice app and is free, up to 5 users, if you use the "STARTER" option.

In this post, as an example, I will show how I detect if my AIS receiver/dispatcher stops receiving AIS targets, sent to Vesselfinder, and how an alert is forwarded to the SIGNL4 app.

I'm using NodeRed on a Raspberry Pi to realize the function

Ring doorbell install and relay

The electrical install instructions for the Ring Doorbell maybe could be a little easier to find  ? 

So will give some links where you are connecting to

1. Internal doorbells
2. No internal doorbell but charging the battery
3. External relay, triggering "anything"
4. Wireless relay

Ring Device manuals are found here.

Homebridge made simple, HOOBS

Updated 2021-08-08 !

I have written several post about the HomeKit Bridge, Homebridge(HB), but if You want another simple way, with GUI, to handle the server and plugins the guys at HOOBS have done a nice software package.

I personally prefer the Homebridge "native" install, which seems to be updated more frequently.

Raymarine AXIOM and NMEA0183

Updated 2021-07-24 !

Many newer MFD:s don't have any NMEA 0183(N1) connector. The  Axiom don't even have any Seatalk NG connector anymore, just the Device Net micro connector for NMEA 2000. Loosing the  N1 info, too for example the old VHF (position data for DSC), could be a problem so how to solve it ?

Some solutions

• Pick N1 data from the AIS
• NMEA 2000, N2 to N1 konverter
• SeaTalk NG, NG to N1 konverter

AIS dispatcher, stand alone

Updated 2021-07-14 !

The dispatcher "aisdispatcher"(AISD), Linux v1.2, from AISHub.net receives NMEA 0183 VDM/VDO messages, (NAIS) via an UDP/TCP connection, or serial interface, and forwards it to one or several destinations as UDP streams. It works at command line with no GUI.

Please note ! This software is "labeled" deprecated and the AISHub guys recommend you to use this package, with built in GUI, instead. The old version, described in this post, still works, for RPi OS before Bookworm, and is very lightweight.

The best AIS application ? is found here !

MySQL and NodeRed

Updated 2021-07-07 !

Sometimes the syntax for the Javascript in Node-Red is a little hard to get, despite some Googling. This was evident when i tried the run the "node-red-node-mysql" node inserting data in a MySQL database.

Also timestamps in different environments are a little complicated.

So this post will cover both areas with some code examples done on a Raspberry Pi.

Raspberry fan control, Node-Red

Updated 2021-07-01 !

Do You want to have control over the Raspberry Pi(RPi) ? 

Functions

• CPU Temperature
• CPU Load %
• Free RAM %
• Disk Usage %
• Shutdown and Reboot buttons
• Fan PWM control via GPIO

Other NR posts on this site

Volvo Penta NMEA 2000 Gateway

Updated 2021-06-15

It's always nice to have ALL information at the same place, navigator/plotter, when You are out with the boat. 

What could be missing is the engine information/data. If You have a Volvo Penta from 2006 or later it could be pretty easy.

There are some "standard" NMEA 2000 gateways to choose from, for example; 

• Volvo Penta has it's own 22813366, 3889758
• Raymarine ECI-100
• Maretron J2K100
• .....

HomeKit bridge with Z-Wave

Updated 2021-05-21 !

These devices are available for Apples HomeKit. The devices are Bluetooth, BLE, or WiFi connected so it could be a limited range in Your house.

The Z-Wave solution have a smarter setup running on a type of network called a "mesh network". One Z-Wave product will pass the signal along to another (“hop”) until the final destination is reached. Every device, not battery charged, acts as a messenger; the more devices you have, the more powerful and strong your network is.

Raspberry USB SSD boot made simple ? Check link 

Homekit, temperature with DS18B20

Updated 2021-04-15 !

A cheap and simple way to measure temperature, and have it displayed in the Home app, is to connect one wire (1W) DS18B20 (DS)temperature sensors direct to the Raspberry Pi(RPi) and install a DS plugin.

This assumes that You have Homebridge up and running on a Raspberry Pi 

Check this post !!  "ANY" temp source can be HomeKit enabled.

Wordpress with PHP Everywhere

Sometimes you have to handle things in Wordpress that you can't find any plugin for.

In our case I had to visualize a list from a MySQL database and in another case I had to fetch data from another website.

In both cases I solved it with inserted PHP code which is executing and getting the info.

SignalK switch with NodeRed and WilhelmSK

Updated 2021-03-13 !

Here I'm trying to do the "ultimate" SignalK switch blog post including(no N2K)

• Shelly 1 as the hardware switch
• NodeRed as the function engine
• NodeRed dashboard as input/output interface
• WilhelmSK as input/output, check picture
• A http endpoint as state sensing

The post is ment to be a template where you can pick the parts which are right for your setup.

Raspberry Pi measuring Voltage

I'm always a little confused that as soon as someone wants to get an analog measure to a Raspberry Pi(RPi) they are often taking a detour via an Arduino/ESP or some other microcontroller. 

Why not just take an Arduino peripheral and use it together with a RPi ? 

In my case I needed to measure the voltage across a fresh water tank level sensor in our boat, but i could be any DC voltage. Hints for sending the data to a Signal K(SK) server is found below. 

In this post I will use an ADS 1115(AD), or ADS 1015, as AD converter.

Scanner GUI with NodeRed

In a former post I installed CUPS printer software for a Cannon printer. The scanning functionality is supported by the package SANE. But there is no nice GUI for the scanning function so I made one, with NodeRed(NR), which I really think is "wife" enabled.

Homebridge, retrieve accessories information & status

Having Homebridge(HB) up and running it's simple to retrieve and visualize status or measurements from accessories.

For example I'm using the Aeotec MultiSensor 6,(AM6), via the z-way plugin, where I'm sensing the light level. Since Im living in northern Europe it's not very accurate to switch the indoor lightning by sun-rise/set. So instead I'm using the AM6 together with the EVE app to switch the lightning. 

To visualize the measured values over time I'm using NodeRed(NR) and a HomeBridge plugin

Free Gmail mail merge with Sheets

There are several mail merges applications where you can merge information from Google:s "Sheets"(GS), but not so may free ones that are good.

The point using mail merge is that you can personalize your outgoing mails and you will fore sure get a better response rate.  

There should also be said that if you are having a free Gmail account you are limited to 100 outgoing mails per 24 hours.

The first application, free !, handles the merge via a GS with a built in JavaScript macro and in the second application, 25 free mails per 24 hours(limit in app), the merge is done via an installed GS add-on with many nice functions.

Eniro charts using SignalK & Freeboard

Do you know about the SignalK workspace at Slack ? It's a really nice space where you could meet the developers and also get support.

If you don't are active there you can get an invite filling in your e-mail adress at

http://slack-invite.signalk.org

I'm following the dialog on Slack and for some weeks ago I stumbled over a post from @chris saying that you could get, with internet connection, the online charts from Eniro displayed in Freeboard. As you see in the picture it's just for the Nordic countries.

Another post installing offline charts.

WeatherLink weather template

Updated 2022-02-21 !

If You are interested in building Your own weathersite with information from Davis Weatherlink(DWL), and don't are a skilled programmer I can really recommend Node-Red(NR). In this post I give an example how to start with the NR dashboard GUI and DWL V1 API.

!! Please note new version with the latest v2 API !!

If You want a more advanced weather site/template this is a very nice one coded in PHP.

Raspberry and external storage/disk

There is a post, link will follow below, from the Raspberry Org site which is very informativ and handles how to connect your external hard disk, SSD, or USB stick to any of the USB ports on the Raspberry Pi(RPi), and "mount" the file system to access the data stored on it. 

So there is no need for a rewrite and this post will therefore continue with how to connect to a Windows server, (Other SMB or Samba servers will also work), both temporary and automagically at boot. 

Check this post RPi booting from an USB drive !

Kamado gasket glue

The gasket on our Kamado Joe was falling off after a very hot pizza cooking project. After some Googling, search link here, I found several post where people, to my surprise, used 3M™ Super 77™ Multipurpose Spray Adhesive.

I'm surprised due to it's just specified to handle up to 65 °C, 150 °Fahrenheit. 

It was also not available in the nearest shops so searching a bit further I found ...

Speedtest vs ISP and at home

Updated 2020-11-30 !

Sometimes you are doubtful about the performance of your home network, or versus the ISP, and wonder, where is the bottleneck ?

After some Googling I found some favorite applications, implemented on a cable connected Raspberry PI(RPi), which do the job so You can start measure and stop guessing.

A speedtest, 

• checking Your ISP, with just a bash script
• for Your home network

SignalK, stream data changes

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 and subscribe to any change of data from the SK server.