Wave Generator: Implemen Sawtooth Waves

[mariobehling]

Implement Sawtooth Waves in the analog device. Compare info at http://onlinetonegenerator.com

Currently, there is no feature in wave generator and oscilloscope to produce sawtooth waves just like sine, triangular and square waves.

Needs some changes on firm ware side as well

Open Issue

[mariobehling]

This feature can be implemented as an Android feature first as well, before we add support to the hardware itself. Some instruments (Luxmeter, Oscilloscope) are supported through components on the device itself. We can also have the Wave Generator provide a way to show features using the phone without a device.