The
software of the system consists of several tasks as follows:
Scanning and Debouncing the Keypad
The keypad is connected to
PORT C of the MCU (As described in Hardware Design page). In order to read the keypad
the scanning code used in lab
4 was used.
Calibrating the Postage Meter
Considering the fact that
the stepper motors have to turn different times for different sizes of
envelopes, we added a calibrating part to the code which user can change the
length of the envelops for each size. Initially the system is calibrated for
three sizes and can be upgraded for up to nine sizes.
Running the System
This part of the code is
responsible for turning each stepper motor based on the size of the envelope
entered by the user. The system is set up in such a way that it first turns the
first two motors and then stops for a short time, stamps and at the end turns
the last two motors to push the paper out and continues this process until all
the envelops are stamped. Number of envelopes to be stamped will be entered by
the user.
The system was tested after
completion of each test code and each component was also tested separately.