Building

I made a prototype board to test out the design. Pictures below show the sequence of build steps. This can be assembled on a breadboard or protoboard easily, and the circuit board shown is available from Aisler.

You will need to solder the supplied male header pieces on the sides of the breakouts. This may best be done with the header trimmed to the proper number of pins and pressed into a breadboard then placing the breakout board on top. You may wish to refer to the tutorial Collin's Lab: Soldering.

adafruit_products_board.jpg
The board from the top.
adafruit_products_Si7021.jpg
The Si7021 breakout with the female header strip.
adafruit_products_mounted_underboard.jpg
The sensor mounted below the board.
adafruit_products_cutting_the_lid.jpg
Cutting a hole in the lid for mounting the sensor.

The sensor is placed inside the jar and, for my build, long headers are used to go through the lid of the jar to the electronics on top of the lid.

A four conductor wire could also be used between the board in the jar and the board outside. 

Be sure to seal the lid connection so humidity cannot get inside. Also, do not let metal lid edges touch bare wires which could cause an electrical short circuit.

adafruit_products_sensor_in_lid.jpg
The sensor mounted in the lid.
adafruit_products_mounted_under_lid.jpg
Mounted sensor from below.
adafruit_products_done1.jpg
Finished build.

The design has proven itself and prototype units have been working reliably for 6 months on the initial battery charge. A more productized version 2 is currently being designed.

This guide was first published on May 21, 2018. It was last updated on May 21, 2018. This page (Building) was last updated on Jul 28, 2019.