Software Planning

To start planning our software flowchart for this system, we first made a states chart, depicting the roles of each I/O device based on the use case and state of the crutch. The main categories are manual, standing with the crutch, regular use (walking), and carrying the crutch. Determining required states of each I/O device helped us iron out prior assumptions about use cases and develop a better understanding of how to integrate the software and electronics for this project.

After the state chart was finalized, it was used to create the software flowchart seen in the figure below. This chart only takes into consideration when the crutch is turned on. After checking the current position of the support legs based on the state of the limit switches, the system checks for manual vs automatic state based on button inputs.

If the crutch is operating in manual state, the system simply checks for when the button is pressed again and decides if the legs need to retract or extend based on the current position. If the crutch is operating in automatic state, the system then goes through a series of sensor input checks to determine when the supporting legs should be deployed or retracted. This logic is based on the state chart.