Since very recently I have two identical PT100 sensors set up inside the same fan-aspirated shield. The first sensor is read using the Adafruit MAX31865 breakout board, while the second is linked to a 4-20 mA current loop transmitter. In both cases, a Wemos D1 Mini microcontroller is used to process the signal. For the […]
Using a 4-20 mA PT100 transmitter
In this post, I explained how I used an Adafruit MAX31865 clone in order to read a PT100 temperature sensor. Since then, I’ve tested an original Adafruit version as well. Accuracy from this board is a lot better. While I had to add a calibration offset of somewhere between 0.8 and 1.5 degrees to configurations using the […]
Looking for stable PT100 readings
In a previous post I explained how I used the MAX31865 with a Wemos D1 Mini to read a PT100 sensor. This worked, but initial readings were erratic. Readings were also off by about 1 degree C. Almost two weeks later, I have tested 3 different PT100 sensors. I now have an Arduino sketch running […]
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 […]
Apogee TS-100 first impressions
I was losing the last light and had to get a flash light while connecting the last wires Tuesday evening (August 17th), but I have the TS-100 up and running. Without battery backup for now. I will fix that later. Adding this new shield to my setup has triggered a whole series of new tests […]
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 2: power supply
Project Apogee requires me to rethink the power supply of my weather station. When I start writing this, the Meteodrenthe weather station runs on solar power only. The Davis components have their own panel inside the transmitters. Other custom elements use 2 watt 6 volt panels by Voltaic Systems. This has been an ideal solution […]
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 […]
Mei 2021 was koud en nat
De vijfde maand van 2021 is ook de vijfde koudere maand op rij. Na een zeer koude april is ook mei met een gemiddelde van 10,62 graden bijna 3 graden kouder dan gemiddeld (normaal ~13,4). Het referentiepunt voor weerstation Lieving, het KNMI in Hoogeveen, eindigt met een gemiddelde temperatuur van 10,76. Mei was bovendien erg […]
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 […]