S15: Motion-Controlled RC Car - Revision history

146 user3: /* Implementation */

2015-05-27T03:37:36Z

‎Implementation

146 user3: /* Hardware Interfaces */

2015-05-27T03:36:32Z

‎Hardware Interfaces

146 user3: /* SJOne */

2015-05-27T03:33:50Z

‎SJOne

146 user3: /* SJOne */

2015-05-27T03:15:09Z

‎SJOne

146 user3: /* Photo Interrupter */

2015-05-27T03:10:11Z

‎Photo Interrupter

146 user3: /* Design & Implementation */

2015-05-27T03:07:13Z

‎Design & Implementation

146 user3: Undo revision 17695 by 146 user3 (talk)

2015-05-27T03:06:38Z

Undo revision 17695 by 146 user3 (talk)

146 user3: /* Software Design */

2015-05-27T03:02:24Z

‎Software Design

146 user3: /* Abstract */

2015-05-27T03:01:36Z

‎Abstract

146 user3: /* Implementation */

2015-05-27T03:01:01Z

‎Implementation

@@ Line 206: / Line 206: @@
 [[File:S15_146_G3_IMG_motor.png|500px|left]]                     [[File:S15_146_G3_IMG_servo.png|460px|center]]
-The photo interrupters are used to monitor wheel rotation. An interrupter was mounted around a disk attached to each differential. In the photos above the rear wheel speed sensor assembly and the front wheel speed sensor assembly are on the left and right, respectively. Notches were cut into the disks so that as they spun the outputs of the interrupters would rise and fall. The SJ One board monitored these signals using its GPIO inputs and counted the rising edges over a set period of time to determine the speed of the axle. Being a rear-drive vehicle, the rear axle rotates faster than the front in a slip condition, and the program responds by reducing throttle.
+The photo interrupters are used to monitor wheel rotation. An interrupter was mounted around a disk attached to the output of each differential. In the photos above the rear wheel speed sensor assembly and the front wheel speed sensor assembly are on the left and right, respectively. Notches were cut into the disks so that as they spun the outputs of the interrupters would rise and fall. The SJ One board monitored these signals using its GPIO inputs and counted the rising edges over a set period of time to determine the speed of the axle. Being a rear-drive vehicle, the rear axle rotates faster than the front in a slip condition, and the program responds by reducing throttle.
 == Testing & Technical Challenges ==

@@ Line 115: / Line 115: @@
 === Hardware Interfaces ===
 The Transmitting Module used the following interfaces:
-* I2C Bus
+* [http://www.socialledge.com/sjsu/index.php?title=Embedded_System_I2C_Tutorial I2C Bus]
 ** Used for reading the orientation value from accelerometer sensor
-*SPI Bus
+*[http://www.socialledge.com/sjsu/index.php?title=Embedded_System_Tutorial_SPI SPI Bus]
 ** Used for transmit commands from Nordic wireless sensor to receiving board
 The Receiving Interface used the following interfaces:
-*SPI Bus
+*[http://www.socialledge.com/sjsu/index.php?title=Embedded_System_Tutorial_SPI SPI Bus]
 ** Used for receive commands from Nordic wireless sensor from transmitting board
-*GPIO
+*[http://www.socialledge.com/sjsu/index.php?title=Embedded_System_Tutorial_GPIO GPIO]
 ** Used to read the axle speed from the front and rear
-** Used to passing PWM signal to the motor and the servo
+** Used to pass PWM signal to the motor and the servo
 === SJOne ===

@@ Line 131: / Line 131: @@
 [[File:S15_146_G3_IMG_SJOne.png|center]]
-The SJOne board is running FreeRTOS. It has Nordic Wireless sensor, Accelerometer sensor, and PWM built-in functions for communicate two boards wirelessly and provide power signal to control the external motor.
+Our project used two [http://http://www.socialledge.com/sjsu/index.php?title=SJ_One_Board SJOne boards], both running FreeRTOS. For our project we used the built-in Nordic Wireless system, Accelerometer, GPIO, and PWM functions.
 === Servo, Motor & Motor Controller ===

← Older revision		Revision as of 03:15, 27 May 2015
Line 131:		Line 131:
	[[File:S15_146_G3_IMG_SJOne.png\|center]]		[[File:S15_146_G3_IMG_SJOne.png\|center]]

		+	The SJOne board is running FreeRTOS. It has Nordic Wireless sensor, Accelerometer sensor, and PWM built-in functions for communicate two boards wirelessly and provide power signal to control the external motor.

	=== Servo, Motor & Motor Controller ===		=== Servo, Motor & Motor Controller ===

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 [[File:S15_146_G3_IMG_photoInt.png|200px|center]]
-The photo interrupters we chose were the Motorola MOC7821. These devices contain an infrared LED and an infrared-controlled transistor. When the gap between the LED and the sensor is open the transistor turns on and allows current to flow, when an object passes through the space between the LED and the sensor the transistor turns off and behaves like an open circuit.
+The photo interrupters we chose were the Motorola MOC7821. These devices contain an infrared LED and an infrared-controlled transistor. When the gap between the LED and the sensor is open the transistor turns on and allows current to flow. When an object passes through the space between the LED and the sensor the transistor turns off and behaves like an open circuit.
 === Software Design ===

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   [[File:S15_146_G3_IMG_flowchart_receive.png|500px|center]]
-=== Software Design ===
+=== Implementation ===
-'''Transmitting Module'''
+The built-in sensor that reads the tilt direction of the SJ One board.
-The transmitter first reads the accelerometer data in both the x and y directions and encodes them in an integer. That integer is sent to the vehicle using the Nordic Wireless system.
+*Step 1: Initialize accelerometer sensor.
-  [[File:S15_146_G3_IMG_flowchart_transmit.png|200px|center]]
+*Step 2: Read X and Y axis from the sensor and get the orientation of the board.
-'''Receiving Module'''
+*Step 3: Encode the function and speed number as a single integer and pass them to the wireless task.
-The SJ One board on the vehicle, waiting to receive data, accepts the integer. The vehicle reads the wheel speeds at the front and rear axle.  This is done by reading the signal from the photo interrupters many times in a row and incrementing a counter each time the signal transitions between high and low. One counter holds the number of transitions read from the front axle and the other counter holds the number of transitions at the rear axle and the task determines if the vehicle is in a low traction situation based on the two counter values. The car then translates the encoded command using one of two throttle maps, based on the traction situation, and uses that to set motor speed and servo angle.
+'''Nordic Wireless''' (nRF24L01).
- [[File:S15_146_G3_IMG_flowchart_receive.png|500px|center]]
+The Nordic wireless sensor is built-in on SJOne Board. It used to send and receive data from one SJOne to other. For our project, it is used to send an encoded x and y tilt of the control board to the board on the vehicle. The following steps were taken to implement the Nordic wireless system
 == Testing & Technical Challenges ==

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 == Abstract ==
-The Motion-Controlled RC Car will allow inexperienced users to drive a high-performance RC vehicle. This is accomplished with a tilt controller, which is more intuitive than a traditional RC transmitter, and a speed-limiting system that will reduce the potential for crashes.
+The Motion-Controlled RC Car will allow inexperienced users to drive a high-performance RC vehicle. This is accomplished with a tilt controller, which is more intuitive than a traditional RC transmitter, and a slip-limiting system that will reduce the potential for crashes.
 == Objectives & Introduction ==