esptemp8c

Open source, n-channel temperature logger using esphome for Dallas DS18B20 sensors.

Version 2 changes

• 4 pluggable headers - I felt that 8 was excessive, and you can actually put any number of sensors by combining them since they all communicate on the same 1-wire bus.
• Smaller Case
• ESP32-C3 Mini - Programming via native USB-C support!

What's in the box

• Fully assembled circuit board
• Two black PCB's that are faceplates for the Hammond case with the proper cutouts

Sensors

They can be found at various locations, including DFRobot, Adafruit, Digikey or the usual suspects.

You will need to find out your sensor ID's as per the esphome documentation.

In theory, this unit can handle any number of sensors if you start piggy-backing the terminals for multiple sensors.

Powering

Only one power source should be used. - USB-C Jack (5V) - Screw terminal - It is designed for 24VAC. 12VAC is probably the minimum required for AC. - YOU WILL DAMAGE THE BOARD ABOVE 24VAC - 7VDC will be the minimum required amount if using DC, and it has been tested up to 24VDC.

A self-resetting polyfuse is included to protect HVAC equipment if sourcing 24VAC from these units. The polyfuse does NOT apply to power from the USB-C port, as the device supplying power should have overcurrent protection.

Flashing / Programming

You must hold down the button while plugging in the device the first time to enter programming mode. The device will then show up as a USB device on your computer. You can then use the esphome flasher to flash the device. It will then require a power-cycle to be visible.

Subsequent flashing does not require use of the button nor power-cycling - it can be done via USBC or OTA as well.

Enclosure

Fits in a Hammond 1593KBK. Or you can make your own enclosure and 3D-print it (contributions welcome).