The Media Feeder is used to precisely add dry plastic modeling media to the source of the river model. This helps stabilize the system as some media is carried downstream through erosion and sediment transport processes. This has been a product improvement I've undertaken. The old version of the Media Feeder had a hard-coded calibration curve correlating travel distance of the dispensing cone to media output in grams per second. This was often inaccurate due to small factors like differences in spring tension between devices and different media particle sizes depending on which color or mix the customer used. I wrote the software and developed a calibration routine to drastically improve the accuracy of this device. A user fills the feeder with the media they intend to use and they prepare a beaker and gram scale. They run the calibration routine, collecting the media output for each step, weigh it, and input the weight. The calibration happens upon completion of the routine and saves to the EEPROM so it doesn't need to be done again unless they switch media types. I also made the menu easier to navigate and understand and display important metrics only. 

This controller was also modified to work with a new printed circuit board, the Big Muddy Control Board, which I designed for use in all of our scientific instruments excluding the standard K28 Flow Controller.