February 21, 2023

Receive temperature, 433 MHz sensors, with RTL-SDR

In my underfloor heating project, using Node-RED, I have to have one sensing thermometer per room/zone, seems to be 8 in total, so therefore it would be nice with a wireless battery sourced device with good resolution and frequent updates.

During the test phase I used a Z-way device but the resolution was pretty bad. Another device mentioned is the Ruuvi tag but since it's a bluetooth device the transmitting range could be better.

After some googling I went for 433 MHz devices.

February 20, 2023

Z-Wave on Raspberry PI

Updated 2023-02-23 !

Installing a Z-Wave controller on Raspberry Pi is much easier than You think.

The only add on You need is the Razberry Z-wave Shield and free software from the same site.

February 14, 2023

Underfloor heating with PID controller, NodeRed

In a former post I did some hacking/checking how our underfloor heating control system handled the valves, actuators, regulating the heat. 

Now it was time to do some tests with NodeRed(NR), with a PID controllerand a Shelly 1(S1) connected via WiFi and driving the actuator.

The actuators are in my case controlled by 24 VAC and the S1 accepts 110 - 240 VAC, 24 - 60 VDC and 12 VDC. So in this case it was simple to just add a rectifier and a capacitor, to the 24 VAC, to get approx 36 VDC to source the S1.