The Chinese University of Hong Kong

CENG3410 Final Project

Spring 2017

Smart Price Tags

This project aims to build an Zigbee network for electronic price tags

The following features will be provided:

1. Remote price tag update from PC program
2. Android app for recording purchased items by tapping on the NFC tag of the price tag

Group members:

• Terry Tsang
• William Wong
• Alan Chan
• Alison Wong

Update Notes for Arduino Pricetag Controller (xbee_pricetag)

v0.2.1 (5/5/2017) [New features]

• Shutdown NFC module when tag writing is not required to avoid interference and to save power

[Changes]

• Reduce JSON data buffer from 80 to 60 byte

[Known issues]

• Arduino Uno has insufficient memory to implement NFC feature.

v0.2.0 (5/5/2017) [New features]

• NFC tag writing supported (Write product information to a tag so that customers can use thier mobile phone to record the products)
• Compatible with Arduino Mega

[Changes]

• Software serial pin changed to pin 10, 11
• Increased serial buffer size from 60 bytes to 80 bytes

[Bug fix]

• Resolved problem when product data packet is too large

[Miscellaneous]

• Add indent to DEBUG macro tag

[Known issues]

• Arduino would halt if NFC module cannot be initialized
• Arduino

[Notes]

• PN532 is possible to emluate as NFC tag but it is not developed in this program yet
• PN532 supports I2C, SPI and HSU. The program is using I2C for communication
• Due to insufficient memory, do not enable DEBUG mode when compiling into Arduino Uno

v0.1.1 (21/4/2017) [Bug fix]

• Resolved memory leak by ArduinoJSON and RxPacket

[Miscellaneous]

• Provided switch of debug message on software serial pin 9, 10

[Known issues]

• Insufficient memory on Arduino Uno. Should migrate to Arduino Mega in the future
• Funduino Xbee shield routes XBee's UART to Arduino pin 0 and 1 only which make UART NFC module unable to be used on Arduino UNO, which has only 1 UART

v0.1.0 (19/4/2017) [New features]

• Receiving Zigbee Rx packet from hardware UART
• Update display according to received packet

[Known issues]

• Memory leak occurs when using ArduinoJSON libraray to prase data
• High memory usage by ArduinoJSON and Adafruit_SSD1306 OLED driver

Update Notes for Console Program (xbee_pricetag_console)

v0.1.3 (5/5/2017) [Bug fix]

• Status bar not updated after synchronzing one tag

v0.1.2 (2/5/2017) [New features]

• Reload database

[Bug fix]

• Product list didn't refresh after updating all prices

v0.1.1 (2/5/2017) [New features]

• Increase/Decrease all prices by 10%

[Known issues]

• Coordinator may not response in time when tramitting a frame to a non-exist address, leading to synchronzation miss. Should wait for transmit status frame after sending each frame.

v0.1.0 (2/5/2017)

• First version with all basic function implemented (Expect increse/decrease all price)