#HumPi Using a Raspberry Pi to measure the frequency of the synchronous grid of continental europe

• Raspberry Pi 2
• USB-Soundcard with a microphone or line input
• AC-Power supply with V_out smaller than ~10V.
• Voltage divider to 30mV for microphone input, 1V RMS for line in
• Phone connector

• Python2
• SciPy (HowTo)
• numexpr for 2x faster measurements
• alsaaudio and ntplib. You can install these via pip:

    $ pip install -r requirements.txt

==========================

Once started, HumPi captures the signal from an USB-Soundcard and calculates the frequency continuously by fitting a sine wave on the last second of 'sound'. Currently the data is stored to disk. In future versions it might get sent to the netzsinus project.

git clone https://github.com/gillhofer/HumPi.git
./HumPi/python/HumPi.py

• Send data to the netzsinus project
• general improvements