Being developed by us is a kinetic energy harvester that harvests energy as its magnets move through a coil. It is our goal to measure the voltage across the coil when the real system is being moved by an actuator. In order to do so, we have prepared a test bed which moves the kinetic harvester at a particular frequency.
It is important that we sample the voltage across the coil at a particular frequency and send it over UART to MATLAB for further processing. We wish to use an Arduino for this purpose.
The voltage produced by the coil is not a constant voltage. It varies and also becomes negative as magnets move across the coils. I understand that the Arduino ADC cannot sample negative voltages.
I attach a photo of the harvester and the linear actuator that moves the harvester below.
Below is an image of the voltage waveform. Please note the voltage ranges from -3.3 to +3.3. We are able to confirm this with the help of the oscilloscope. I wish to sample at the highest frequency possible. The higher the accuracy the better the readings would be. We intend to use an Arduino Uno.
If all the voltages produced by the coil were positive the ADC can be directly connected to the coil. But it is definitely not the case. Perhaps some circuit / technique to make the output waveform positive is required. We cannot provide a DC shift to this coil as doing so may change the coltage induced by magnets effecting the system.
Whats required is a method we can sample the ac waveform varying from -3.3 to +3.3 with the help of the arduino ADC.
Any advice is a lot appreciated.