S17: Propeller Clock - Revision history

Preet at 15:35, 31 May 2017

2017-05-31T15:35:16Z

Proj user8: /* Project Source Code */

2017-05-27T20:05:58Z

‎Project Source Code

Proj user8: /* Schedule */

2017-05-27T20:02:38Z

‎Schedule

Proj user8: /* Issue 7: Weight Balancing */

2017-05-27T08:10:12Z

‎Issue 7: Weight Balancing

Proj user8: /* Issue 3: Motor RPM not constant */

2017-05-27T08:08:03Z

‎Issue 3: Motor RPM not constant

Proj user8: /* Implementation */

2017-05-27T08:03:51Z

‎Implementation

Proj user8: /* Implementation */

2017-05-27T07:59:47Z

‎Implementation

Proj user8: /* Software Design */

2017-05-27T07:31:47Z

‎Software Design

Proj user8: /* Implementation */

2017-05-27T06:26:01Z

‎Implementation

Proj user8: /* Implementation */

2017-05-27T06:25:25Z

‎Implementation

@@ Line 1: / Line 1: @@
-== Project Title ==
+== Propeller Clock ==
-<b><i><font size = "6">Propeller Clock</font></i></b> (Persistence of Vision Based Analog Clock)
+Persistence of Vision Based Analog Clock
 == Abstract ==

@@ Line 379: / Line 379: @@
 === Project Source Code ===
-*  https://drive.google.com/open?id=0Bz_W74RtLmyJTGJYTDM3Z2tCUWc
+*  https://drive.google.com/open?id=0Bz_W74RtLmyJM1pQNEZLZnVpdWM
 == References ==

@@ Line 130: / Line 130: @@
+|
 * Update Wikipedia Documentation
-| Planned
+| Completed
+| 05/26
 |-
 ! scope="row"| 11
@@ Line 138: / Line 138: @@
+|
 * Final Demo
-| Planned
+| Completed
+| 05/25
 |}

@@ Line 350: / Line 350: @@
 === Issue 7: Weight Balancing ===
-Our PCB is designed such that one side of the PCB has more weight than the other as it is longer. The system was very unstable and was shaking a lot due to the weight imbalance.
+Our PCB is designed such that one side of the PCB has more weight than the other as it is longer. The system was very unstable and vibrated a lot due to the weight imbalance.
-Solution: We added counter-weight to the other side of the PCB which balanced the other arm of the PCB. This improved the stability of the system and made it easier to catch the clock in hand.
+Solution: We added counter-weight to the other side of the PCB which balanced the other arm of the PCB. This improved the stability of the system and made it easier to hold on to the module with hands and we did not need any mount.
 == Conclusion ==

@@ Line 331: / Line 331: @@
 === Issue 3: Motor RPM not constant ===
-We had planned to find out the motor RPM with final load and then build the entire logic considering that RPM. But we soon found out that the RPM was changing all the time.
+We had planned to determine the motor RPM with final load and then build the entire logic considering that RPM (constant RPM). But we soon found out that the RPM did not have the same RPM every time we started the motor. Also, there are minute fluctuations in the RPM when motor runs which causes the clock display to drift/rotate.
-Solution: We decided to dynamically calculate the motor RPM on each rotation.
+Solution: We decided to dynamically calculate the motor RPM during each rotation with the help of reed switch.
 === Issue 4: IR Transmitter & Receiver ===

@@ Line 298: / Line 298: @@
 '''Character Display'''
-* For this we designed the characters which took up 5 x 7 LED matrix. All characters (A to Z) where encoded and any combination of these characters can be displayed. We have at the max 2 degree resolution, hence we can display at the max (360 / 7*2) =~ 25 letters.
+* We designed characters which required 5 x 7 matrix. All characters (A to Z) where encoded and any combination of these characters can be displayed. We have 2 degree resolution, hence we can display (360 / 7*2) =~ 25 letters at the max.
-e.g. to display 'N' we use the following logic:
+e.g. to display 'N' we use the following logic:<br>
-| 0 1 1 1 0 |1
+| 0 1 1 1 0 |1<br>
-| 0 0 1 1 0 |1
+| 0 0 1 1 0 |1<br>
-| 0 1 0 1 0 |1
+| 0 1 0 1 0 |1<br>
-| 0 1 1 0 0 |1
+| 0 1 1 0 0 |1<br>
-| 0 1 1 1 0 |1
+| 0 1 1 1 0 |1<br>
----------------
+____________<br>
-  1 1 1 1 1  1
+  1 1 1 1 1  1<br>
-  1 1 1 1 1  1
+  1 1 1 1 1  1<br>
-  1 1 1 1 1  1
+  1 1 1 1 1  1<br>
-To simplify the design, we have added 3 extra rows so as to make each column a 8-bit (char) data which we can easily store in character array e.g. here N : char N[8]= {0xFF, 0xE0, 0xFD, 0xFB, 0xF7, E0, 0xFF}
+To simplify the design, we have added 3 extra rows so as to make each column a 8-bit (char) data which we can easily store in character array <br> e.g. here N : char N[8]= {0xFF, 0xE0, 0xFD, 0xFB, 0xF7, E0, 0xFF}
 The outermost columns of 1 are to keep blank lines/space between 2 characters. We use LEDs in active low configuration. Hence, here 1 means turn off LED while 0 means turn on the LED. With this method we can have two separate character display lines, one on port 0 (p0.0 to p0.7) and port 2 (2.0 to 2.7) by simply writing char value associated with characters on the corresponding ports.

@@ Line 296: / Line 296: @@
 * Implemented algorithm to vary all time-critical parameters for current angular traversal based on previous Rotation-time.
 * Designed algorithm to glow different LEDs at different angular positions to depict analog-clock time and various messages using characters.
 == Technical Challenges & Issues ==

@@ Line 273: / Line 273: @@
 ''' Calculations '''
 * Dynamic RPM Calculation
-Let Time for 1 rotation be t seconds
+Let Time for 1 rotation be t seconds<br>
+RPM = 60/t<br>
-RPM = 60/t
+Time to traverse 1 degree in 1 rotation= t/360 seconds<br>
+eg. Time for 1 rotation is 100ms (0.1s)<br>
-Time to traverse 1 degree in 1 rotation= t/360 seconds
+RPM= 60/0.1 = 600<br>
+Time to traverse 1 degree in 1 rotation= 0.1/360 = 277us<br>
 === Implementation ===

@@ Line 298: / Line 298: @@
 * Initialized TIMER0/1 parameters for 1 second and 1 microsecond delay respectively.
 * Implemented program to keep track of time in Seconds, Minutes and Hours and also in Microseconds.
-* Designed program to manage dynamic RPM of motor and remove time related errors using GPIO interrupt.
+* Designed program to manage dynamic RPM of motor and remove time related errors using GPIO interrupt rising-edge interrupt given by Reed switch.
 * Implemented algorithm to vary all time-critical parameters for current angular traversal based on previous Rotation-time.
 * Designed algorithm to glow different LEDs at different angular positions to depict analog-clock time and various messages using characters.