EElabper#ad - It can measure the frequency range from 1 hz to 50 megahertz 1Hz-50MHz, can measure the oscillation frequency of most common crystal oscillators, and measure equipment such as radio transceivers.
This is a pic microcontroller based on the frequency meter, with a crystal measurement function and programmable addition and subtraction frequency settings. You need to solder and assemble by yourself, the is input with the standard source, and the wire is printed correctly according to the PCB.
Five digital display, easy and intuitive, all use of in-line components, the circuit is simple and easy to produce. After welding, all the components are directly inserted, and the yellow adjustable capacitor is adjusted to make the display value equal to the frequency. The power supply can use a usb to 3. 5mm power cable, or you can directly input a 5-9V DC power supply at the - and + pads.
KESOTO#ad - Frequency range 1 Hz. Measuring signal amplitude can be up to 30 v. Or xx. Xxx MHz. 50 mhz. This document describes the construction of small frequency counter with a cheap PIC microcontroller and a few seven-segment LED digits.