Contemplations by Thor /tɔː(r)/

 2,5 years ago I decided to upgrade to a AC band capable router. After reading reviews I decided to go for Linksys EA9500. That was a mistake. Coming from a very reliable nighthawk, RT-N66U, the Linksys was a huge disappointment. The software on the EA9500 was never good, and I don't think there was one firmware upgrade in the period I used it either. Secondly, the range was not good. First think I did was to get a Linksys RE7000 repeater. For one of my son's I bought an AC band PCI adapter. Although good tranfer speeds were good, the connection dropped frequently.  I resolved to using the old RT-N66U as bridge for this connection. I tried a custom firmware for the Linksys. I managed to get it installed but it was not stable so I had to revert to stock. For the home office, the EA9500 was very annoying with dropping MS Teams connections. At best, transfer speeds was in the range 200-250 mbps. That was ok, had it only been stable. Last week I decided to replace the home router....

 My airpods have seved me well since 2017, but this winter they started failing to work when cold outside. I figured it was time to replace them. I started reviewing the top-of-the line products out there, and quickly narrowed down the list to three candidates. Bose probably has the best active noise cancelling, otherwise Apple Airpods Pro and Jabra Elite 85t comes out pretty equal. I never liked the Bose design, and with rumors of  new AirPods Pro coming in April, I decided to go for the Jabra. I have Jabra Elite 85h in the office for comminication, and I like them a lot. The software, especially on mobile devices, for setting up the sound options is really good compared to Apple. 85t uses the same software. My biggest concern were the fit. You don't get to try buds, and you don't get to return them. In that sense, the Elite 75t active would have been a safer choice as they are lighter and a more snug fit. When I tested the 85t for the first time, the software told my the fit...

My days in Matlab is definitively not over, but it's a clear trend that more and more people I work with tend to use open source software tools for data analysis and visualization. This has motivated me to test alternative tools and compare them with matlab with respect to functionality and performance. Recently, I've been working with correlation of data from gas sensors. For the SINTSENSE concept, I collect data from the sensors into an Influx 1.x database and plot data using grafana. I found not functionality to plot the correlation between sensors, so I resolved this by extracting data from the database every hour, calculate the correlation cofficients and then push them back into the database. This data was then plotted in grafana alongside the sensor responses. The work with SINTSENSE made want to explore the possiblities of doing correlation analysis on timeseries data. The calculation of the correlation is straightforward, but in order to calulate dynamic correlation, d...

Initial testing of our SINTSENSE analytical systems with PID, SO2, NOX, OX, H2S, and CO sensors have indicated some drift when testing them in ambient air. Especially the electrochemical sensors have been prone to inversion, and some of the sensors show opposite polarities. There is enough examples of published data from sensors of this type without calibration and validation of drift, cross-sensitivity etc., so a proper calibration needs to be done. I have access to a very elegant gas and liquid mixing system that should make it possible to evaporate a solution of benzene, and air mixtures of SO2, CO etc. Air because these sensors require oxygen to function. In the mean time I thought it would be a good idea to test the sensors on the exhaust from my beloved BMW vehicles. So I gave it a go. From the figure it can be seen that for both vehicles the PID sensor saturates at about 35 ppm. No worries: I have on for the working range of 50 ppb to 6000 ppm to try next. The CO sensor behaved ...

I finally got a smart watch! After thinking of buying one for years, I finally managed to choose one. It was hardly any compromise, well maybe except for the price ... I can' think of how many times I almost bought an Apple Watch. The battery life usually held me back: charging the unit every other day was not acceptable. I remember waiting for LTE a while, but when it finally arrived the penalty on battery life (and my wallet) was not acceptable. I record all my physical activities on Strava. It's mostly bicycling, running and walking. Using my iPhone X as recorder has worked great, although there have been situations where I wish I had another alternative for recording the activities. The phone battery is sometimes needed for other functions, and for running with the phone in an armband is cumbersome when you need to look at the map for directions. I am not a dediated 4-by-4 interval trainer. I prefer to run in the forest where the elevation profile gives me natural int...

Our cabin is in the mountains near Tynset. Since we always heat it, it made sense to install a smart plug so that we could control the heating from home, and have it warmed up while driving the 2,5 hours to get there from home. I selected a plug I could control over wifi, and not just an app: D-LINK DSP-W215. Since I have a RPi installed, I created a python script to control it over ssh from home. It works nicely for scheduling, a feature yet to be implemented in the app. Sissel and I have designed a lamp to be installed in one corner. It's a simple wall lamp made in massive oak, a concrete covered socket on a gray textured cord. We had planned to use a led decoration bulb like the ones we already have. I was thinking how to implement on/off and dimming of the bulb, when I found that Philips had the solution: a smart bulb with all required functionality. Home made smart lamp I tested the bulb with the Philips app at home, and it communicated nicely over bluetooth with ...

Well, I could not help my self for long: dumping data to influx is simple and Grafana is pretty self-explanatory.  The Worldmap plugin is not made for temperatures, but I managed to create a map that made sense with respect to temperatures, and to get actual reading when hovering over them. As I have collected no more location information than lat/long, I got an n/a when hovering over the locations. Since I have altitude, I could replace the n/a with some useful information.