Puppy Distractions and Tech Attractions: Continuing the IoT Temp Probe
Written on January 29th, 2024 by Sean Webster
Picture: My new puppy, Fuji. 8 weeks old. Jan 2024
Since my last update, life has taken an exciting turn with the arrival of a 9-week-old Australian Shepherd puppy, named Fuji. As adorable as it is, puppy parenting has been quite the adventure, complete with sleepless nights. This has left me with limited chances and, admittedly, fewer coherent moments to dedicate to personal projects.
Project Update: IoT Temp Probe
Hardware Developement
ESP-PROG
I was looking into a JTAG-esque header for this project, and was reminded of the ESP-PROG board by Espressif. It is available from Mouser
I was unaware it worked for the ESP8266, but after ordering one, I have confirmed that it does. I then put a ESP-PROG header on my board. 
To flash from WSL Ubuntu, I used the command: idf.py flash -p /dev/ttyS9 -b 115200
Layout
Using KiCad, I’ve drawn up a board for my temp probe. I followed this tutorial for layout. I also had a bunch of help from some friends and a few people from the Embedded.fm Slack channel.
Top Render in KiCad: 
Bottom Render in KiCad: 
I found a useful collection of open source KiCad Libraries
I decided to go with a JST XHP-3 Connector for the DS18B20.
Manufacturing
JLPCP is what I used, which was recommended in the youtube video.
There are useful tools to generate BOM files for JLCB, such as this plugin
There is also another interesting BOM generator I did not have time to test.
I sent the design out, only to find out that the footprint for my LM3671 was wrong. I had used a SOT5x3 vs SOT23 Luckily, they caught my error, and I was able to cancel the order with populated components.
I did, however, keep my order of unpopulated PCBs. It was cheap enough, and it was a good silkscreen test. I ended up adding some pictures of my dog, because why not.
The silkscreen came out pretty good 
Here is a grayscale render. I’ve been looking into a way to render more than stls.
{% include stlviewer.html src=”boardv1.stl” width=500 height=300 extrastyle=”” %}
I’ve sent out a fixed version of my files to JLPCB, and am awaiting populated boards.
Next Steps
Hopefully my fixed rev B of the board arrives, and I can load software on it. The production version of software is still in progress, so I plan to continue work on that.
Future Plans
I plan to cover the vinyl portion of the DS18B20 with food grade tubing This content can be found at the IoT Temp Probe Hardware V1 page
Rabbit Holes
In the snippets of time when the puppy is asleep, I’ve managed to stumble upon some intriguing tech topics:
CoAP - Constrained Application Protocol: Delving into this web transfer protocol has been fascinating. It’s designed for constrained devices and networks, making it an ideal study for IoT enthusiasts.
Never Work in Theory: This site offers a unique perspective on software engineering research, challenging conventional wisdom and sparking new thoughts.