F15: Smart Car - Revision history

Proj user22: /* Conclusion */

2015-12-19T16:29:17Z

‎Conclusion

Proj user22: /* Testing & Technical Challenges */

2015-12-19T16:25:04Z

‎Testing & Technical Challenges

Proj user22: /* Implementation */

2015-12-19T16:19:56Z

‎Implementation

Proj user22: /* Software Design */

2015-12-19T16:17:00Z

‎Software Design

Proj user22: /* Motors */

2015-12-19T16:12:58Z

‎Motors

Proj user22: /* Parts List & Cost */

2015-12-19T16:10:59Z

‎Parts List & Cost

Proj user22: /* Parts List & Cost */

2015-12-19T16:09:59Z

‎Parts List & Cost

Proj user22: /* Abstract */

2015-12-19T16:05:41Z

‎Abstract

Proj user22: /* Conclusion */

2015-12-19T16:04:03Z

‎Conclusion

Proj user22: /* Issues Faced */

2015-12-19T16:03:45Z

‎Issues Faced

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 == Conclusion ==
 The goal of the project was to create a car that would be able to follow a line and to display the car's path on an LED matrix. The LED matrix mapped the car's path, but the car was not able to successfully follow a line. This is due to the lack of time that was spent testing. The light of the environment that the car is vital to proper calibration. Because of how varied the environment the car was tested in was, its ability to follow the line was compromised. In addition, the light also cast a shadow underneath the car which affected the photoresistors. Ultimately, the project reinforced the concepts learned in CMPE146, particularly through the use of SPI and I2C drivers for communication between external hardware modules and the microprocessor.
 === Project Source Code ===

← Older revision		Revision as of 16:25, 19 December 2015
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	For the LED matrix mapping, we wrote tests to print out the result of turning a 2D array mapping of bytes into messages over SPI. Each bit that is set in the 2D array represents an LED. To test that each LED was addressed properly, we light up each LED in order until the entire LED matrix is lit up. In fact, due to this test being useful for many applications. We kept this in the code base running parallel to our X and Y plotter. Since the memory used to store the LED mappings was not completely volatile (existed a few minutes after loss of power), we had code to erase the LED matrix using a preprocessor compilation variable called ERASE. If ERASE is set, then the LED matrix will be erased. Otherwise, the LED matrix will be filled up. By compiling with ERASE being set, we guarantee that each time we restart the processor, the LED matrix will be reinitialized.		For the LED matrix mapping, we wrote tests to print out the result of turning a 2D array mapping of bytes into messages over SPI. Each bit that is set in the 2D array represents an LED. To test that each LED was addressed properly, we light up each LED in order until the entire LED matrix is lit up. In fact, due to this test being useful for many applications. We kept this in the code base running parallel to our X and Y plotter. Since the memory used to store the LED mappings was not completely volatile (existed a few minutes after loss of power), we had code to erase the LED matrix using a preprocessor compilation variable called ERASE. If ERASE is set, then the LED matrix will be erased. Otherwise, the LED matrix will be filled up. By compiling with ERASE being set, we guarantee that each time we restart the processor, the LED matrix will be reinitialized.
		+
		+
		+	'''Testing the Smart Car'''
		+
		+	We ran several tests for this design and went through several tuning methods but each method we attempted would force the car to go off track very often. We would place the car to go onto the center of the tape but detect that the phototransistor readings were actually quite different from each other due to the lighting and shadows made from the car. After each iteration, the correction algorithms would be changed but to no luck. At one point we managed to keep the robot on track by having very small error correction but the moment it hit a turn, it would not be capable of adjusting quickly enough.

	== Issues Faced ==		== Issues Faced ==

← Older revision		Revision as of 16:19, 19 December 2015
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	'''Brightness'''		'''Brightness'''

−	Since we decided to ~~have~~ our ADC channel have a positive correlation to the intensity of light, we can interpret the mV reading as a starting point for measuring the brightness of the environment of the photoresistor. This raw data can be used in more advanced ways such as passing it through a filter or for a calibration step but that is a possible option that we did not explore too deeply.	+	Since we decided to make our ADC channel have a positive correlation to the intensity of light, we can interpret the mV reading as a starting point for measuring the brightness of the environment of the photoresistor. This raw data can be used in more advanced ways such as passing it through a filter or for a calibration step but that is a possible option that we did not explore too deeply.

← Older revision		Revision as of 16:17, 19 December 2015
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	'''Displaying position'''		'''Displaying position'''

−	The position of the car will be centered around the center point of the LED matrix which we will map to ~~positions~~ (1,1), (1,-1), (-1, -1) and (-1,1) ~~where the~~ first digit is the position we are at West vs East while the second ~~dition is~~ how far we went North or South. Positive corresponds to traveling East and North for the first and second digit respectively.	+	The position of the car will be centered around the center point of the LED matrix which we will map to coordinates (1,1), (1,-1), (-1, -1) and (-1,1). The first digit is the position we are at West vs East while the second digit represents how far we went North or South. Positive corresponds to traveling East and North for the first and second digit respectively.

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 === Motors ===
-NPN transistors were used to control the power source to the motors. There was very little documentation for the motors used so initial tests with varying input voltages yielded that these motors seemed to operate successfully at 5V. This method should not be used on documented motors, but instead make sure to adhere to the specifications provided. In addition, if the input voltage is negated, the motor had the ability to rotate in the opposite direction. For the application, only the positive voltage was utilized since the car did not need to go backwards. For turning purposes, one motor moved slower than the other.
+NPN transistors were used to control the power source to the motors. There was very little documentation for the motors used so initial tests with varying input voltages yielded that these motors seemed to operate successfully at 5V. This method should not be used on documented motors. Instead make sure to adhere to the specifications provided. In addition, if the input voltage is negated, the motor had the ability to rotate in the opposite direction. For the application, only the positive voltage was utilized since the car did not need to go backwards. For turning purposes, one motor moved slower than the other.
 === Photoresistor ===

@@ Line 136: / Line 136: @@
 ! scope="row"|
 | Estimated total
-| $
+| $243.12
 |-

@@ Line 89: / Line 89: @@
 | Electric tape
 | $1.99 ea
 |-
 ! scope="row"| 1
 | Compass
-| $9.95
+| $14.95
 |-
 ! scope="row"| 2
 | Motors
-| $10
+| $0 (reused)
 |-
-! scope="row"| 2
+! scope="row"| 1
 | LED matrix
 | $24.95 ea
 |-
 ! scope="row"| 2
-| Photo transistors
+| Photoresistors
 | $1.20 ea
 |-
@@ Line 122: / Line 118: @@
 | $6.49 ea
 |-
-! scope="row"| 4
+! scope="row"| 2
 | NPN transistors
 | $3.29 ea

@@ Line 2: / Line 2: @@
 == Abstract ==
-A smart car with three wheels will be designed to have the capability of following high contrast lines. Options for the lines include using black Sharpie, black duct tape, and white duct tape. Afterwards, it will send back a CSV file format with 0s and 1s. 1s denote that the car was traveling in the area of the map. Using a peripheral compass, the car will also be able to draw a map of the route that it took.
+A smart car with three wheels will be designed to have the capability of following high contrast lines. Options for the lines include using black Sharpie, black duct tape, and white duct tape. Afterwards, it will send back an X and Y coordinate which will be used to plot a visual representation of where the car has traveled onto the LED matrix. The controller board is in charge of plotting the LED matrix while the car's board is in charge of sending X and Y coordinates.
 == Objectives & Introduction ==

← Older revision		Revision as of 16:03, 19 December 2015
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	'''Varied lighting conditions'''		'''Varied lighting conditions'''

−	The car was tested in various conditions, which affected our ability to calibrate the ~~phototransistors~~ properly. Additionally, the lighting in the environment often cast a shadow on one of the ~~phototransistors~~, giving them very different values even though the car was centered on the white line. This drastically affected the car's ability to successfully follow the line.	+	The car was tested in various conditions, which affected our ability to calibrate the photoresistors properly. Additionally, the lighting in the environment often cast a shadow on one of the photoresistors, giving them very different values even though the car was centered on the white line. This drastically affected the car's ability to successfully follow the line.