This very easy to use and inexpensive function generator produces 0-200,000 Hz signals of many different waveforms: sine, square, triangle, ramp (up and down), and staircase (up and down), as well as user defined arbitrary waveforms (AWG) easily programmable through USB.
For sweeping of selected waveform signal, start and stop frequencies and sweep rate can be set independently. For square signal, duty cycle is variable from 1% to 100%.
The DDS also generates servo test/control signals in micro-second resolution with user programmable pulse width, amplitude, and cycle.
Quick and straightforward setting of frequency (or period), amplitude, and offset is done with digits. 
Frequency (period), amplitude, and offset can be incrementally adjusted with rotary encoder (step size can be set to any value).
 

These and many more nice features make it a perfect testing instrument for electronic hobbyists, students and anyone with a homelab, for less than 50€!
 
Note: You'...