Im working on the saawtooth part of the circut now (labeled n the photo) and reached an empasse, ts kind of hard to make a way to be able to select the mode (square, sawtooth, sine) because of the way the frequanc selector works, i tred to have a switch conected to all the buttons so f i need square wave its conected to 3V but if i need a sawtooth its conected to the negative pin of the op amp. The problem is this; even i select where the buttons connect i cant choose wich generator works wiithohut havng a bunch of redundant switches any suggestion are welcome