Thats where this function generator sent to us by [Mohonri]comes in. Based around a ATTiny25 and a rail to rail op amp which is able to replicate frequencies from 1Hz to about 40KHz, in square ...

If you have a cheap function generator it’s likely to contain a one-chip solution that generates approximations to sine and triangle waveforms through modifying a square wave with a set of filters.

The traditional analog function generator with its customary ... so the problem is how to generate an acceptably accurate sine wave. This usually involves some method of conversion of the triangle.