How does FT8 work?

FT8 is unfortunately impacting amateur radio negatively. CW and SSB activity goes down and the modes that require serious skills to operate are not practiced. FT8 can today run fully automated QSOs. However FT8 is interesting from a technical view. Advanced techniques such as FFT, correlation, 7×7 Costas matrixes are used to synchronize, error correct and decode data. Here is an interesting presentation that gives you a lot of the the technical details. (Reference / Full credit to WB2FKO Mike Hasselbeck)

MQTT and Husdata H66 in Home Assistant

If you have a smart home with a geothermal well feeding a heatpump from IVT or some of the other suppliers, the chance is good that Husdata has a IoT device for it so you can monitor your heating system in your smart home system.

To set up MQTT for Home assistant, you need to go to Addons, backups and supervisor. Find Mosquitto and install it. Then go to the info tab and select start on boot so it starts again on a boot. Go to configuration and take a note of the network ports for later.

Reboot HA

Then goto Devices and services, check that you see mosquitto

Then you need to set up a new user in HA for mqtt: go to people and zones / select the users TAB. Make a new user with usernamexyz and a safe and long pw. of your choice.

Now go into your husdata H66 web gui on the ip it resides on. Goto the Config tab. Find the MQTT settings. You need to point to the IP of your HA server. Also now give the username and password you did set up in HA earlier.

My MQTT settings look something like this:

Now check the log of the husdata H66. If it says something like “08:03:00 MQTT subscribing to: MAC ADDRESS OF THE H66/HP/CMD/#” then you are good. It will try to connect several times, however after some tries it will go over to try once per hour. Then its best with a reboot of the H66 to speed it up unless you are very patient in your fault finding process.

Now go to the HA user interface: Go to devices and services. Find the mosquitto broker “tile”. If you now see that there are xx entities available in that tile like below, you are good.

Click on all the entities link in the tile and select all the entities you want to get data for. When you are done, click ENABLE SELECTED.

Now do a reboot of both HA and the H66 (it doesn’t hurt).

Now you should be ready to make dashboards and use the sensors.
Also, check this tutorial out:

(Disclaimer: you do everything on your own responsibility. The information given may be incorrect. By interfacing to your heat-pump you may change settings that may lead to overheating and/or damage of your heatpump, loss of heat or other problems. If you do not know what you are doing, don’t do it).

Orbi mesh network RBS350 / RBR350 in chained mode (not star mode)

Earlier versions of orbi RBS350 (satellite) and RBR350 (router) before ca. version would have to be set up in chained mode manually. If you have a house where one part of the house does not have coverage from the base the system will now automatically set it self up in chained mode. IN the outermost nodes you even have BOTH 2.4GHz and 5GHz service for the units that want to connect even if the back-haul is wireless and uses 2.4 or 5.

How to fix ORBI wifi mesh setup so all units on the network is visible

If you have experienced that some units on your Wifi network that were previously connected to your fiber or cable router cannot anymore be connected on your internal network – after you installed a set of ORBI mesh units – the reason may be that the ORBI system is not set up in access point mode. If it is set up in router mode, there is an internal firewall that acts in addition to the normal firewall you have in your cable or fiber modem. Log into the orbi unit with and go to ADVANCED/Advanced/Router/APmode and select AP mode. Reboot the ORBI units and you are all set. All units on your Wifi network are visible (on your internal network). Read more here:

How to use a psychrometric chart (absolute vs relative humidity in air)

Have you ever wondered how to use a psychrometric chart? With this tool you can convert from relative humidity (RH) to absolute humidity (gram water per kilo air). Reference: Perry Peralta NC State University. Full credit goes to the author of the slides.

You can also click the download link if you want to view the document on your laptop or mobile device.

Wifi setup for Home Assistant via COMMAND LINE

Power on HA

Have a screen and a keyboard connected

When you see the ha> prompt enter login

Then do this:

nmcli radio


Now scan and list available wifi access:

nmcli device wifi rescan

nmcli device wifi

wifi list

Connect to wifi:

Use quotes around your ssid and password:

nmcli device wifi connect "YOUR_SSID" password "YOUR_WIFI_PASSWORD"

This will try to connect to your SSID and will generate a network profile for you if successfull.
The output will be similar to
"Device 'wlan0' successfully activated with...."

Then check your connections again:

nmcli con show

con show

You should be seeing at least two profiles and both green.

If you are seeing some profiles you’d like to get rid of you can remove them using:

nmcli connection delete CONNECTION_NAME

delete con

These may have two separate ip addresses on your network: one for ethernet, one for wifi.
You can check the ip addresses using:

ip addr show

Now connect to http(s)://your_wifi_ip:8123 in your browser.

Credit goes to:

How to use a rpi zero as a USB to Ethernet forwarder for Adalm Pluto

ZR6TG has written up a good tutorial on how to use a rpi zero as a USB to Ethernet forwarder for QO-100 satellite. This enables you to get rid of your active USB extender cable and makes it possible to place the pluto and dish far away from the shack. Click below to check it out.

D-Link DCS-2670L IP-camera with audio in Blue Iris (howto)

D-Link IP cameras are fairly OK and available IP cameras. On several of my sites I have video surveillance with AI and motion detection incl. thermal and night vision. However the D-Link DCS-2670L wide angle camera is known to be difficult to get working with Audio. Either the audio is crackling, there is no audio or there is distortion. The solution was simple: use DCS2030/21xx RTSP profile in Blue Iris

DCS-2670L setting in Blue Iris
DCS-2670L setting in Blue Iris. Audio and video works.

Slik settes boliglånsrenten

Boliglånsrenten varierer ikke direkte etter Norges Banks styringsrente. Den er på kort sikt påvirket av renten bankene kan oppnå i kapitalmarkedet. Denne renten kalles NIBOR. Over tid vil NIBOR og styringsrenten følge hverandre ganske tett. (NIBOR er en noe utdatert renteindikator og mange referanser viser nå til NOWA). Finans Norge forklarer her hvordan rentene på boliglån settes (klikk på linken):

Utlånsrenten følger NIBOR ganske tett. NIBOR følger på lengre sikt styringsrenten ganske tett.

What time series database to use for IoT systems?

While most of the tutorials online nowadays describe influxdb as a very good time series database we discovered that there are some serious considerations you should do before selecting a time series database for your next IoT project.

Here are some findings we did and questions we should have asked when we researched and selected time series databases for a new design of an IoT system:

  • To design a stable database engine suitable for production typically takes 10+ years of user feedback and experience from smaller scale testing and continuous improvements. Several of the “high ranking” databases has not been around for that long
  • mySQL and ORACLE have stable database engines by now, but they are not time series databases
  • Influx has rewritten their database engine several times over a period of few years. This may be a hint to that they are still struggling to converge on a stable database design
  • We found several very worrying statements in bug reports related to influx such as “please help, our production database is suddenly corrupt”, “the database has crashed, the backup is also corrupt. There must be something fundamentally wrong with storage”, “we have discontinued functions iusedthisextensivelyandthereisnowayaroundit() in the next release due to a complete rewrite of the database engine” etc.
  • Some databases have very inefficient compression algorithms. They will compress, but when trying to read from a compressed table, the penalty is pretty big and it goes too slow forcing you to use uncompressed tables
  • Some databases do not support writing to compressed tables (!). You have to decompress before writing. This takes a lot of time. And there is no API support to check if you try to write to a compressed table. You have to resort to parsing log messages before writing. Yes it is true.
  • Even if a database shows up high in a ranking, it may be because of it has the highest growth rate. That does not tell you much. If you look closer, you may discover that all the big guys already use more conservative and well proven time series database systems. That people reading tutorials download and install influxdb does not mean that Google, Facebook, Amazon etc uses it. It does not mean that it is the best time series database available.
  • Some databases claim to support continuous aggregates. However did you benchmark and test properly that the functions used for reading from the aggregates are stable, does not require 100% CPU, and does not crash your database engine? You may be in for a surprise.
  • Some time series databases does not have support for regular data types and regular SQL syntax. This means you will have to have TWO databases. One for configuration data and one for time series.
  • Some time series databases from the cloud vendors are extremely expensive as soon as you come up into production. Did you actually check the cost? If not you may be in for a BIG surprise.
  • Even plotting time series in a web browser may be too slow. Did you check if your time series database can decimate and deliver data to your front end in real time?