Sensor Light

A smart light bar — illuminates dark places on-demand by gently powering-up/down a LED stripe depending on the ambient light level and a detected human presence.

Hardware core is a ESP32-H2 SoC connected with an VEML7700 ambient light sensor and a small but effective LD2410 radar based presence sensor. This automatic floor light is completely self-contained.

It does not use Wifi or Zigbee features of the ESP32-H2 SoC and does not connect to a smart home system with that firmware here - but one may add such a feature smoothly, of course.

Status:

• Software: ready, tested; release-candidate
• Hardware: beta; release-candidate

Sketch

TODO replace with final photo / Gif

Hardware

Pictures

Wiring diagram

The wiring diagram includes a separate flash adapter (on the left side), which is can be connected to the main unit via a 4-pin connector. It's required to flash the ESP32-H2 once it's soldered. The programming board connects to a computer or any other suitable programming environment via a standard USB-C connector. Please note:

• This programming board is not strictly required in a scenario, when one has its own way of initial flashing the SoC before soldering and don't wish to update the firmware later
• While flashing / monitoring the chip via the flash adapter, we still need power supply through the 12V socket

Parts

References

• Switching with transistors

Software

Complete program code is included here. In order to build it and flash the ESP32-H2 one needs a ESP32 Rust embedded toolchain.

We are going to use an ESP32-H2 SoC with Rust embedded Toolchain with [std]. For that and this project we need:

• Rust compiler (see www.rust-lang.org)
• Rust embedded toolchain for ESP32-H2 for projects using std lib Follow the instructions for [std] projects in this book chapter: The Rust on ESP Book - Setting Up a Development Environment Notes on this: - ignore sections for [no_std] - When it comes to the step espup install, you should consider using espup install --targets esp32h2 instead, to avoid installing lots of unnecessary dependencies for unused Espressif targets.
• cargo build

To flash the ESP:

• cargo run

Terms & Conditions

Feel free to use anything here for learning, building your own version or make a product out of it and even sell it. In case you find it useful, the author would be delighted to notice a small donation in Solana to his wallet: FTMfeKYhpVAouuwXjpJXhnT13fkeNJqQsRGMBxBo1GML.

Pull requests are welcome.

bitmagier, July 2024