On the stock Creality V2.2 mainboard, you can add an extra thermistor (TH2). I connected a thermistor on that one and placed it all the way up in the enclosure.

The board also has HEATER1, unused. Although it should be PIN9, I can`t get it controlled. So I had to switch plans to use the enclosure plugin on Octoprint.

For the thermistor I used a DS18B20, which I connected to the GPIO 4 of my Raspberry Pi. For heating elements, I used 2 100Watt 220V passive alu heating blocks, the Nimbus D175. Underneath these two elements, I placed a 12V 40mm fan. This gives just a little push for the hot air to go up, without making too much airflow.

With the enclosure plugin, I can control the heating units in my enclosure. It does not work perfectly, sometimes I do not get an update from the thermistor for about a minute or 3. Have to find out why. The output of the Raspberry Pi goes to my own switchboard, so I can manually switch on/off or let Octoprints enclosure control the heating.

For safety reasons, I have an external thermostat connected. I got it from Amazon. This one has a switch. Unfortunally, it`s off when heating and on when it goes to high. So made a circuit with 5V to a 74LS04 Inverter, so it gives me 5V when heating and 0V when temperature is reached. That triggers a second SSR, which is put serial to the SSR for heating control. So if the Octoprints plugin fails and keeps heating, or when the controlled SSR fails, I have a second SSR with temperature control.

More to come…