$[15$ points$]$ You are an entry$-$level embedded systems engineer giving supervision to a summer intern EE student. The student's first assignment is to design an MCU$-$based data acquisition system that samples a sensor$,$ computes statistics on the data, and transfers the data to a display and serial bus storage device. The student has been coding various software components and wiring hardware based on various demo codes and a description of the DMA controller in the code comments.

When the student brought the system to near$-$completion, he tried it for the first time and parts of it seem to work, but not overall. The display shows the first $1-$second$\text{'}$s worth of data over and over. He thought he knew what the problem might be$,$ so he tweaked the DMA control code, fixed a statistics calculation error, and adjusted the scale of the display. The system does work for brief periods of time then fails again. Your intern comes seeking your wisdom. You ask to see his architecture diagram, and he has none.

a$)$ Help the intern draw an architecture diagram

b$)$ Identify at least $3$ classic system development blunders the intern has stumbled into.

c$)$ Suggest at least $3$ debugging steps the intern should do to gain more information about where the fault$($s$)$ may be occurring and to test for correct operation.