Description: This is a frequency meter based on PIC microcontroller, add and subtract with crystal vibration measurement functions and programmable frequency Settings, five digital tube display, convenient and intuitive, easy to make; Feature: Measured frequency range 1 Hz to 50 MHz (1Hz to 50 MHz); Can measure most commonly used crystals of oscillation frequency; Five precision resolution (e.g., 0.0050 KHz, 0.0050 MHz, 11.059 MHz); Automatic range switching, do not need to switch; Programmable Settings, add and subtract frequency used for measuring the transceiver and other equipment; Optional power saving mode, did not change significantly within 15 seconds if frequency display will be automatically closed; Can use generic USB interface power supply, also can use an external power supply or 9V battery; Element number less, all into components, simple installation and debugging