The Wio Period Meter shows the period of CMOS/TTL pulses. The console is a Seeed Wio Terminal programmed with the Arduino sketch WioPeriodMeter.ino.
The terminal gets power through the USB-C connector. The BNC cable is connected to white cable of the right Grove socket (D1, pin 15).
When pulses are detected (falling edge), the fan on the bottom starts rotating and the period between the pulses is shown on the screen.
The USB-C link virtual COM port (baud-rate 115200 bps) allows reading the period from software (sending any character will return the last recorded period in microseconds). This requires the driver to be installed first.
Version 2 introduces three modes:
- Pulse Period
- Low Pulse Width
- High Pulse Width
Press the top left button to toggle through the modes (keep the button pressed for > 0.5 s).