Mein Netzfrequenz Monitor - ganz einfach nachzubauen !

The device consists of only two parts. If you need the Arduino code, send me an email. Did you make a circuit board or improve the code? You can also send me a photo of your build. Email: [email protected] I can publish your modifications here if you want. For the development, I used a Nano because I had a few on hand. There were some indications of the resonators' lack of frequency stability. I tested four Nanos: Nano.1 USB-B 9 ppm/K - 0.5 mHz/K Nano.2 USB-B 8 ppm/K - 0.4 mHz/K Nano.3 USB-C 130 ppm/K - 7 mHz/K Nano.4 USB-C 141 ppm/K - 7 mHz/K The temperature stability of my Arduino Nanos with USB-B is much better than that of my Nanos with USB-C. This is probably due to the fact that the newer USB-C Chinese clones use inferior resonators. Visually, there's no discernible difference. With calibration at 21°C and a room temperature of 20-22°C, an older NANO (at 50 Hz) shows no noticeable deviation – the newer ones show ±7 MHz. Arduino MICROs (and some others) have built-in crystals that are presumably much more stable. Unfortunately, I don't have one to test with. My UNO has a resonator with 10 ppm/K and a crystal with 3 ppm/K. I can't comment on frequency drift due to aging. Current prices (January 2026): 3 NANOs approx. €11, 3 MICROs approx. €19