When he’s not leading the charge on complex builds, this mobile tech lead is busy solving plumbing debacles with DIY franken-gadgets fashioned from cat food boxes and Halloween props.
Case in point (and in J1’s words): Unfortunately, we’ve run out of hot water with our new fancy heat pump hot water cylinder twice now. Plumber said we should never run out, as the number in our household, performance of it, and its increased capacity should make this basically impossible.
So I whipped up this ugly thing on Friday, mostly out of Oscar’s kitten food box, lined with tinfoil, and a plastic lid I scuffed up to diffuse the light. The main electronics have been (temporarily) pillaged from “Spooky eye’d Steve” (the Halloween prop I made last Halloween, which was going to include a camera so the eyes could track you, but I didn’t end up getting that far).
Wrote new firmware for it (with help from Gemini, since I don’t write code often) to wake up, take an image every 10 minutes, send it via MQTT, then go back to deep-sleep.
Then wrote some python (again with help from Gemini) to get each image that comes through, apply various transformations (to clean up the image), before running it through OCR, and emitting the result to a different MQTT topic which NodeRed is watching and stores in InfluxDB for use in Grafana.
The OCRing was flaky, even after switching from pytesseract to EasyOCR, so I did end up having to manually review the images. But did manage to mostly generate a nice chart to show the plumber to help with diagnosis.
Here are images of the hacked together device:
This is a clear picture of the target:
This is an example of what the image looks like from the ESP-CAM’s potato vision:
This is what it looks like after transformations before supplying to the OCR:
And this final pic is obviously the chart I supplied:
For now, it’s keeping tabs on hot water usage — but tomorrow? Who knows. With a bit of tinkering, this humble setup could be repurposed for any number of weird and wonderful data-driven missions around the house.
You never know… a bold idea, a few odds and ends, and a little ingenuity might just take you places.