Author: namit

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Monitor Your Home Energy in Real Time with ESP32 and Home Assistant

Check out this wirte up by our member Christian Kortenhorst.

With energy prices climbing and smart homes becoming the norm, having a clear view of your household power usage has never been more valuable. That’s what motivated me to create a compact, real-time energy display powered by an ESP32 and a 2.8″ TFT touchscreen—fully integrated with Home Assistant for accurate, live data at a glance.

Why I Built This
I already had a power monitoring system installed through my home energy provider. While it gave a general idea of usage, it was far from ideal:

  • It only updated every 30 minutes to an hour, making real-time decision-making impossible.
  • It didn’t show live solar production, even though I had solar panels installed.
  • It lacked any visual clarity—just vague numbers with no context on where power was flowing.
  • Most importantly, there was no breakdown of grid vs solar vs battery usage. – Without opening my phone
  • Also existing power monitor does not do negative number so any feedin from solar does not show.

That’s when I realised I needed something more flexible, accurate, and immediate—custom-built to show the exact figures I cared about.

Old OWl monitor

The Hardware

Here’s what I used for this project:

  • ESP32 Microcontroller – Powerful, Wi-Fi enabled and Arduino-compatible. https://www.amazon.co.uk/dp/B0DXFBKKQB?ref=ppx_yo2ov_dt_b_fed_asin_title
  • 2.8” TFT Touch Display (320×240) – A colourful and responsive screen with touch input, perfect for compact dashboards.
  • Home Assistant – My existing setup, which already tracks energy through integrations like the Energy Dashboard or MQTT sensors. Shelly

What It Shows

The display cycles through or organises a simple dashboard view with key stats:

  • 🌞 Solar Power: Current generation in watts.
  • 🏠 Home Consumption: Real-time power draw.
  • ⚡ Grid Usage: Whether I’m importing or exporting electricity.
  • 🔋 Battery Level: Charge percentage and power flow.
  • Water temperature in boiler

These are live, accurate figures from my energy system—not delayed estimates.

How It Works
The ESP32 fetches data from Home Assistant using either its REST API or MQTT feed. I chose to parse JSON data from Home Assistant’s /api/states endpoint, which allows me to pull specific sensor values and display them on the TFT screen.

To keep it fast and responsive:

  • Sensor values update every few seconds.
  • Touch input can be added for toggling views or brightness.
  • The layout is clean, using large fonts and colour-coded elements for clarity.
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Repair Cafe – Vanmoof S3 Dead Battery

At one of our Repair Cafes, we had an electrical bicycle that would not turn on because it had been sitting idle for three months and would not charge. Vanmoof has no repair options since they have gone bankrupt over the last few months and not supplying any spare parts.

With nothing to lose, we started to take the bicycle apart to find out what it’s made of and if it’s serviceable. With little or no documentation on how to take it apart and without specialised tools and security bits we cracked it open.

Issue 1: Unlock The Bicycle

The bicycle needed an app to unlock it, the bicycle would turn on for 1-2 seconds and then turn off. To solve this I used a generic 36v charger and plugged it in to get the smart cartridge to boot up. This allows you to unlock your bicycle and ride as a push bike.

Issue 2: Repairing The Battery – Manual Recharge

The bicycle was not holding any charge in the battery. The battery is located in the bottom rale. You need a specialised tool to remove the wheel however I found if you deflate the wheel and take out 2 bottom screws you can slide the battery out. There was no power coming out of either the charge ports or discharge ports. By connecting the DC benchtop power supply to discharge ports battery started to charge. Voltage when plugged in was 28v. I let it charge up to 36v and then put the battery back into the bicycle.

Conclusion:

The Vanmoof bicycle is back up and running and fully functional again. It was well worth the time.

Thanks to all TOG members who helped out with advice, I am in no way an expert on this.

This repair was carried out by Christian Kortenhorst.

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[Show slideshow]
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Raspberry Pi outdoor Camera

The project is to create an outdoor stop motion camera that can be powered over one cable and we can connect to remotely to monitor building site.

  • Shopping list:
  • Raspberry Pi 3 or 3. I bought Raspberry Pi 3 Model B+
  • MakerHawk Raspberry Pi Camera IR Fisheye Wide-angle 150-160 Degree 5MP OV5647 Webcam Automatically Switching between Day-Vision and Night-Vision Shooing Mode for Raspberry Pi 2B/ 2B+/3B/3B+/4B
  • Active PoE Splitter Adapter Power Over Ethernet 48V to 12V
  • POE switch 48V (already had)
  • 6.2″x3.5″x2.5″(158mmx90mmx64mm) ABS Junction Box Universal Project Enclosure w PC Transparent Cover
  • Nylon Cable Gland with Locknut
  • CAT5 cable (internal or external)
  • AmazonBasics Circular Polarizer Filter – 77 mm

Software we are running on on Pi is Raspberry and the image capture is imgcomp by Matthias-Wandel https://github.com/Matthias-Wandel/imgcomp (very easy and well documented how to setup)

Things left to do:
Mount camera on off stands so camera is closer to camera filter.
Setup backup fo images nightly to google drive (rclone) https://rclone.org/

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Air compressor fixed

Air compressor in workshop died few week ago and finally getting around to taking it apart to see what issue is. Seamed like motor might have ceased however it was quick fix.