ESP 32 creates square wave with adjustable duty cycle, frequency and amplitude which amplifies to max 24 V and modulates audio signal via a differential amplifier
Amplification level is set by front panel potentiometer and displayed with 2 digit LED or LED bar graph
Amplitude, Frequency and duty cycle should be set from a small App
I would prefer a Chinese developer or one with strong experience on how to get this produced in China.
Please make a fixed quote so you do not need to ask me "WHAT IS YOUR BUDGET'" - if this little project works out well I will have many follow up projects for you.
Audio signal shall be used for light and electric therapy.