In my previous post about reading thermistors with a Wemos D1 Mini, I observed resulting output seemed a bit high at lower temperatures, while readings were lower compared to other sensors at higher temperatures. As I explained, that problem was in part due to variable input voltage. Even after fixing that issue, there were a […]
Category: Programming
Getting accurate NTC thermistor readings with a Wemos D1 Mini
A thermistor is a very common type of thermometer. They are cheap and readily available in many forms. At first glance, thermistors are very simple devices. It is basically a resistor that changes its resistance with temperature. Very popular are 10K NTC thermistors. Negative Temperature Coefficient (NTC) means that resistance drops when temperature rises. 10K […]
Uploading to the Weather Underground API
Since all data processing for Meteodrenthe is custom made, this includes sending updates to Weather Underground (WU). I realize that the name of WU has been tarnished in recent years. Nevertheless, it is still one of the most popular websites for PWS owners. Meteodrenthe uploads data there as well. This PWS page is updated once […]
Reading a PT100 sensor with a Wemos D1 Mini
In my never ending quest for better temperature readings – or other ways of doing so, at least – I’ve begun trying other sensors than the SHT35. One of them is the PT100. It’s supposed to be very accurate. It it used in many different situations, from laboratory settings to industry. It’s also used in […]
Project Apogee part 3: controlling the TS-100
In my previous post I addressed the power supply needed to run the Apogee Instruments TS-100 fan aspirated shield in my setup. The next step is building a controller for the fan that allows me to vary the fan speed and read the actual rpm being achieved. The idea is that the controller can query […]
Project Apogee part 1: fan aspiration
My big project for the summer of 2021 is adding a fan aspirated radiation shield to my setup. My primary shield – the Barani MeteoShield Pro – is a superb product, but a passive shield it remains. It suffers from overheating in windless conditions. Those conditions do not occur too often at my location, but […]
Tuning the AS3935 lightning detector
As I pointed out in my previous post on the AS3935 lightning detector, the AS3935MI library available through the Arduino IDE works quite alright. However, every time I boot the Wemos D1 Mini with it, I get a warning that the calibration of the resonance frequency failed. As per the datasheet, the frequency needs to […]
WeatherLink Live, local API and barometer
A few weeks ago, I made the switch from reading my Davis sensors with the Meteostick to the Davis made WeatherLink Live. Though I still like the concept of the Meteostick, the reception is fairly poor and sometimes it would stop receiving data and require a reboot. One thing you don’t have with the WeatherLink, […]