This module consists of two mbeds, linked by a Serial UART. The mbed with the screen is named 'Screen', and the other mbed (connected to the RFID reader) is 'Slave'.

Design Brief¶

The Screen must display:

• When the door is Unlocked
• Which locker to go to
• How much charging time is left
• The name associated with the RFID (or just the tag number)
• The weather data from the weather module, upon request.

The Slave needs to:

• Read the RFID tag number if a tag is swiped, and pass it to the Screen.
• Possibly act as a data slave, using it's serial connetions to connect to the weather station.
• Pass the data to the Screen, when the Screen is not busy.
• Develop a method to control access to a locker using the RFID reader

Current Function¶

RFID reader¶

• Reads an RFID tag and stores as a character array.
• Sends RFID to the screen mbed using the serial UART, character by character, to fill another character array,
• With this RFID on the screen mbed, we can display to the LCD.

Locker flags¶

• Sends a pulse to the locker when an RFID is present - telling the locker to unlock.
• Receive a level from the locker when the locker is unlocked (so we can display to the screen).
• Sends a pulse to the locker when RFID is presented a second time - telling the locker to lock.

Display¶

• Continually checks for information at the serial port
• Different start characters let the program know what data is being sent
• Corresponding capitalised characters signify the end of transmission of this piece of data
• Can display weather data

Future Plans¶

• Configure the LCD's SD card reader to hold a file of RFID tag numbers, their owners, and their current charge credit (time left).
• Format the screen readings into a more pleasing layout (especially weather)
• Be able to store large amounts of data from the battery