Tag Archives: DHT11

Temperature Display for 3D Printer Enclosure

Posted 29 July 2021,

In my ongoing quest to convert my MakerGear M3-ID printer from a nice bench decorative piece into a real functioning printer.

Recently I have been having real problems with using dissolvable filaments with my MakerGear M3-ID dual-extruder 3D printer. I couldn’t get either the PVA (water soluble) or HIPS (Limonene soluble) filaments to stick worth a damn to the BuildTak surface. In the process of troubleshooting the problems, I discovered that the M3-ID has real trouble getting the print bed temperature above 100C – at least in my nicely air-conditioned lab spaces. So, I went on the hunt for a decent enclosure, and found this 3D Upfitters model.

3D Upfitters Enclosure for the MakerGear M3 series (M3 shown, but the same enclosure works for the M3-ID)

The dimensions shown for the enclosure look like they would work for my setup, so I ordered one – we’ll see. In the meantime I started thinking that I might like to control (or at least monitor) the internal temperature, especially the ambient temperature at the location of the Octoprint module and control electronics. My worry is that at high bed temperatures, the ambient temps might get worryingly close to the max temps for the control electronics. 3D Upfitters does offer a temperature readout, but I was pretty sure it wouldn’t accurately represent the ambient temps around the electronics, so I decided I would modify an earlier project to create a custom temperature probe, using the venerable Nokia 5110 LCD display, a DHT11 temperature/humidity sensor, and a Teensy 3.2.

I decided to use the Teensy 3.2 micro-controller rather than an Arduino UNO to avoid the issue with 5/3.3V level conversion and because I’ve used this item several times before in other projects. I’m sure there are cheaper alternatives, but this is what I had available, and they are rock-solid products. Here’s the schematic:

And here are some photos:

And here is the code that interfaces to the sensor and drives the display:

Stay Tuned,

Frank