Hello! We would like to use the pumps to automatically inoculate the pioreactors. We cannot use the media pumps for this, because the media tubes would get contaminated with bacteria. Instead we would like to use the waste tubing to transfer the inoculum. Therefore, we would like to change the direction of the waste pumps for the inoculation process. We would like this change of direction to be controlled by software (rather than switching the wires around for the media and waste pumps) as we are running a cluster (24 workers) large enough that the manual switching feels fidely and error prone.
My understanding is that changing the direction of the polarity isn’t possible through the dosing automation or through the relay plugin (which turns whatever is connected to the GPIO pin on and off) and we would need some new hardware which changes the polarity (something like this h-bridge motor driver), and then I’d need to write a background job which controls the Raspberry Pi’s GPIO pins. I think I can build on the SoftwarePWMOutputDevice so that it can control multiple pins to allow me to make the pumping bidirectional. I might need to do something similar to the dosing automation’s safety catches to prevent too overflow of liquid.
Has anyone done something like this before? Any collective wisdom gratefully received. 