====== Minute - April ======

[[start:classes:principlesofdesign:allograftpreservation_2012:start|Back to allograft preservation page]]

===== 04/04/2012 =====

  * Met with Prof. Lima to discuss about current objectives.
  * With the help of Prof. Lima and machine shop technician, we built five cylindrical chambers with input filter holder and output quick-release insert valve.
  * We setup the pump system (All tubing and valve manifolds)
  * All parts seemed to fit perfectly.
  * Automatic arduino control system did not function properly - and on top of it, we fried an arduino chip (Oops)
  * Re-uploaded arduino code to the spare arduino.

  * **Link: **[[Cylindrical chamber]]

===== 04/06/2012 =====

  * Re-examined the control system to prevent any further damage.
  * We concluded that 2 Amps from the power supply may be the problem, so we decided to use different power supply (24V 0.5A)
  * Wired up automatic arduino control system and solenoid valves.
  * Confirmed that the system functions properly with the new arduino chip.
  * Tested solenoid valve functions.
  * Automatic pump operation did not work - we need to find a new relay or use transistors for 24V relay that we currently have.
  * We found out that we need to modify our code since we are using different pump now.

  * We wrote an arduino code for stepper motor control (make a complete turn forward and backward)
  * Uploaded the code and wired up the system.
  * Since our motors use 24V, we need to connect an external power to the motor shield.
  * Confirmed that the motor works.
  * ** Be very careful about wire configuration - wires must be connected in right order **

  * **Link: **[[Pump system with cylindrical chambers]]
  * **Link: **[[Solenoid valve control with arduino]]
  * **Link: **[[Stepper Motor Testing]]

===== 04/13/2012 =====

  * Air pressure within the chamber often caused back-flow of liquid
  * Therefore we needed to have a sterile air inlet / outlet
  * Machined the cylindrical chamber rids to install an air filter
  * Installed a socket for 0.2 Micrometer in-line filter
  * Back-flow of liquid is minimized, but pump's flow rate must be reduced to 5
  * Modified the arduino code (Made each filling phase longer [55 seconds each])

  * When evacuating liquid, one chamber is always left behind due to uneven rate of evacuation through the valve manifold
  * Liquid in the last chamber does not evacuate completely due to excess air supply through other three chambers
  * The set up functions well with four chambers at most
  * Decided to use only four chambers

  * **Link: **[[Installation of air inlet/outlet filter]]

===== 04/18/2012 =====

  * Confirmed that the relays function properly to operate pumps
  * Valve control #3 of the original board was broken
  * Needed to make a new board

  * Soldered a new control system board that incorporates valve control, pump control, and arduino on a same board

  * **Link: **[[New control system board]]

===== 04/19/2012 =====

  * Started building the Drawbot
  * Found new stepper motors with greater torque

===== 04/20/2012 =====

  * Conducted final testing of the pump system.
  * Decided to use bigger air filters to let more air in to prevent back flow.
  * Everything works well, done with the pump system !

  * **Link: **[[Final system test]]

  * Drawbot competition
  * Coded the Drawbot - drew HelloWorld and triangle

  * **Link: **[[Drawbot Competition]]

  * We need to make an instruction manual
  * Get ready for shipping
  * Find IV bag with 3 Outlets

===== 04/25/2012 =====
  *Pump, instruction manual, and chamber system shipped!!

Link here- picture of wrapped and packed stuff. 
***Link to instruction manual pdf****