IdeaSpark ESP32 1.14in TFT Deep Freezer Temperature Monitor

This is a basic built to allow you to integrate an ESP32 device to monitor a "dumb" freezer and set alerts for any malfunctions before items inside the freezer spoil if they thaw by integrating into HomeAssistant via ESPHome.  Wiring is relatively straight forward with 3 pins for the DS18B20 sensor (+V, Ground, and Analog Signal to a GPIO pin).  Print all components flat on build plate w/o the need for supports.  Utilized a combination of M2x5mm and M2x8mm screws and standard breadboard jumper wires.  

Assembly:

The DS18B20 sensor gets mounted into the sensor box using 2x 5mm screws.  The sensor box then gets mounted to the rear panel for the main ESP32 board utilizing 4x 8mm screws (screw through the rear panel).  The ESP32 gets mounted to the front face plate utilizing 4x 5mm screws.  (Don't forget to install the buttons!)  After wiring the DS18B20 module board to the ESP32, mount the front face plate to the main box using 4x 8mm screws.  Secure the lid on the sensor module box with 4x 5mm screws.

Printed all components utilizing PLA on an Ender5 S1.  Used a hobby knife to clean up flashing on some of the printed surface edges and used a hole reamer to clean up the holes for the USB buttons. 

Installation:

Installation is fairly straight forward.  You can mount the module utilizing the two mounting holes and self-taping screws, however, be cautious of where you poke holes in your freezer as many units have hidden wires and refrigerant lines in the side walls.  Another key critical step is to ensure that you seal any wiring going into the freezer enclosure.  I printed a simple wire "ramp" with tunnel that allowed the freezer seal to still remain intact and prevent outside air (i.e. moisture/humidity) from entering the freezer.  This will prevent your freezer from icing up, requiring frequent thawing.  Simple STL file/model file was included for wire penetration.  I mounted it to my freezer seal edge using 2-sided tape and sealed the DS18B20 sensor wire with some caulking. 

You may need to "print" a suitable mount for your DS18B20 sensor element.  There are many available on sites such as Printables.com and Thingiverse.com.  Pick one that fits your needs.  I ended up picking an aquarium "mount" and modifying it slightly to fit on the wire shelves of my freezer.

Hardware & Electronics:

• ideaspark ESP32 Board

• DS18B20 Temperature Sensor

• M2x5mm Self-Tapping Screw

• M2x8mm Self-Tapping Screw

• 2-sided Tape (for sensor wire door seal)

• Breadboard Jumper Wires