Arduino square wave generator up to 1Mhz

This is a simple square-wave generator that basically uses the TimerOne library allow you to generate a PWM signal at pin 9 in the range from about 5Hz to 1 Mhz, and you can adjust the duty cycle from 0 to 100%. Device is very simple to build and consist only a few components: - Arduino nano microcontroller - LCD Display - Three pull Up resistors - and three push buttons The pulse generator has the ability to adjust the pulse repetition period using the buttons connected to digital inputs 6 and 7 of the Arduino. 13 input pin allows you to adjust the duty cycle. The duration and duty cycle readings are displayed on the first row of the LCD 16 × 2 indicator, and the frequency readings are displayed in the second row. The minimum step for adjusting the pulse repetition period is 1 μs, so the frequency will change discretely, for example, 1 μs is 1 MHz, 2 μs is 500 kHz, 3 μs is Hz, and so on, and as the frequency decreases, the smoothness of its adjustment increases. This is q