My wife and I got solar this winter and my excitement about our power generation grows with our proximity to the equinox. To keep me from obsessively checking my phone, I build this esp32-powered dial to put on a shelf in our living room. It shows the current kW output for our solar system with a cute rising sun and some numbers.

Parts

• Seeed Studio Xiao ESP32C3 ($5)
• Adafruit Automotive Stepper Gauge ($10)
• L293D H-Bridge Driver ($9)

Files

• 3D-Printed Housing and dial (Thangs model)
• ESPHome Configuration
  • Update the Home Assistant entity ID for your power sensor and secrets as needed

Notes

The stepper gauge does not have a real datasheet nor specify a voltage, so to keep things simple I'm just using the 5v from the USB powering the ESP32 board. I suspect this is not quite high enough because over time, the gauge seems to drift due to skipped steps. I played around with stepper speed, but it always seems to have this problem. My fix is to run the "stepper_init" script twice a day, which just turns the dial all the way forward and then all the way backward before going back to the last known value. (I've seen my dashboard gauge cluster dials do this when I start my car).