(Update11) CA2


CA2 REPORT: NEW FASHION MEDIA - Color Changing Fabrics

Wen Yingqian U0509434


The scope of the project is to invent a non-emissive color changing fabric module. The change of the colors on the fabric can be either passive or human controllable. As a summary, the limitation of the project is highlighted below:


1.      Fabric display 2. Multiple colors 3. non-emissive 4.controllable



Things I have done in the past 3 months:


1.   Decided the direction of the project

  • Reseach on the commercially available colour changing inks.  (Click to see details)
    • Photochromic, thermochromic, liquid crystal, electrochromic
    • After comparing the pros and cons of each type of ink, finaly decide on to experiment on Thermochromic Ink.
  • Purchased thermochromic ink, TMP04 sensor, and other components required in the project.
  • Experiment with my groupmate Andre to test the property of Thermochromic ink when mixed up; verified that multiple colour effect could be achieved when we mixed up different types of thermochromic inks with different activation temperature
  • Prepare colour changing fabric for jayanth's presentation (Click to see details)

2.    Preparation

  • Getting familiar with Altium Designer, IAR system, CSS complier, and winPIC800 for PCB design, program compliering and PIC program loading.


3.  The design of the Matrix (Click to see details)
  • Design and revise the schematic of Matrix & Matrix Control System
  • choice of switch:
    • 1. controllable by PIC 
    • 2. dual direction current flow (MOSFET is excluded)
    • current using 5V relay, however, considering the high switching frequency, need to find more feasible switch to fit in
  • Design the switching algorithm
    • the 4 peltier module of the same foudamental module share the same PI control for temperature control
    • assign a fixed time slot of each Peltier Module
    • sequentially connect each peltier module and check its tempeture. since the peltier module has relatively large time constant, if the frequency of  the switching algorithm is of several orders of the time constant of the peltier module, it is feasible to maintain the temperature of 4 peltier modules using one PI controller. 
  • Current direction control
    • use full bridge motor driver (L298)
  • Implemented a 2*2 matrix hardware with current direction control for testing purpose.
 4. Planning of system integration
  • Matrix switching scheme
  • Multiple PI controller
  • Display module
  • Serial communication with PC 



 Future work:


1. Testing the matrix circuit with PI controller

      -     Study on Jayanth's program and hardwear

             -     the PI controller

             -     temperature sensor circuit

             -     power supply

             -     decoupling capacitors

      -     Check the feasibility of the switching algorithm

            -     take note of the temperature changing characteristis

      -     Decide the following parameters

            -      PI controller parameters

            -      Switching frequency of the Matrix switch

            -      Power supply of the control circuit and driving circuit


2.  Searching for multiple PMW output IC

      -     for each PIC, there are only 2 PWM outputs

      -     to have a larger scale of the matrix, multiple PWM outputs required

            -   one way is to have multiple PIC

            -   an alternative is to find IC can generate multiple PWM


3.  Implement a GUI interface to communicate with the Matrix

      -     design creative matrix pattern

      -     design simple animation