F15: Minion

Grading Criteria

• How well is Software & Hardware Design described?
• How well can this report be used to reproduce this project?
• Code Quality
• Overall Report Quality:
  • Software Block Diagrams
  • Hardware Block Diagrams

    Schematic Quality

  • Quality of technical challenges and solutions adopted.

Abstract

This section should be a couple lines to describe what your project does.

Objectives & Introduction

Show list of your objectives. This section includes the high level details of your project. You can write about the various sensors or peripherals you used to get your project completed.

Team Members & Responsibilities

Sensor Controller:-

• Bhupendra Naphade
  

Motor & I/0 Controller:-

• Sudheer Doddapaneni
  
• Keerthanaa Alagudurai
  

Communication Bridge & Android Controller:-

• Akshay Kanchar
• Asmita Deshpande

Geographical Controller:-

• Amit Pachore
  
• Sindhuja Gopalakrishnan Elango

Master Controller:-

• Gaurao Chaudhari
  
• Akshay Dabholkar

Tester:-

• Bhupendra Naphade
  

Treasurer:-

• Keerthanaa Alagudurai

Hardware:-

• Amit Pachore
• Gaurao Chaudhari
• Bhupendra Naphade

Release:-

• Akshay Kanchar

Schedule

Common Schedule

Sl. No	Start Date	End Date	Task	Status	Actual Completion Date
1	9/22/2015	9/28/2015	RC Car and important component buying	Completed
2	9/29/2015	10/6/2015	1) Algorithm and architecture 2) Setup of car and decision on CAN Id's	Completed
3	10/7/2015	10/13/2015	1) Coding and final set-up of car 2) Successful communication of CAN bus. 3) Car in running position.	Completed
4	10/14/2015	10/20/2015	Sensor Data gathering and movement according to sensors.	Completed
5	10/21/2015	10/27/2015	1) LCD Display working and finalizing the data to be displayed on LCD module. 2) GEO data gathering and controlling of car using Android module.	Completed
6	10/28/2015	11/3/2015	Integration of all the modules into one.	Completed
7	11/4/2015	11/10/2015	Inclusion of new features in the car.
8	11/11/2015	11/17/2015	Testing depending upon the newly added features.
9	11/18/2015	11/24/2015	Testing of Car and testing the self driving capability	Completed
10	11/25/2015	12/1/2015	Testing of Car

Sensor Controller Schedule

Sl. No	Start Date	End Date	Task	Status	Actual Completion Date
1	9/20/2015	10/5/2015	Study available sensors and place order	Completed	10/4/2015
2	10/6/2015	10/13/2015	Collaborate with the other sub teams to finish the CAN bus communication	Completed	10/13/2015
3	10/13/2015	10/20/2015	Develop simple test code for the sensors	Completed	10/18/2015
4	10/21/2015	10/30/2015	Interface all sensors and develop code for reading all sensors.	Completed	10/30/2015
5	10/30/2015	11/2/2015	Positioning of sensors and identifying dead band if any	Completed	11/2/2015
6	11/2/2015	11/5/2015	Work on light and battery sensor (optional)
7	11/06/2015	12/17/2015	Final testing and debugging

Motor & I/0 Controller Schedule

Sl. No	Start Date	End Date	Task	Status	Actual Completion Date
1	9/21/2015	9/25/2015	Order LCD Display	Completed	9/25/2015
2	9/28/2015	10/3/2015	Going through the motor concepts and PWM	Completed	10/2/2015
3	10/4/2015	10/9/2015	Intreface the DC and SERVO Motors with SJONE board	Completed	10/8/2015
4	10/10/2015	10/13/2015	Establishing basic CAN communication with other modules	Completed	10/13/2015
5	10/11/2015	10/16/2015	Getting the car to run with the PWM signals from Motor controller	Completed	10/15/2015
6	10/17/2015	10/23/2015	Research on Speed cotrol method and sensor for the same interface LCD display with LPC1758 via UART	Completed	10/21/2015
7	10/23/2015	11/4/2015	Establishing reliable CAN communication for IO & Motor with others	Completed	11/4/2015
8	11/5/2015	11/12/2015	Integrate Speed sensor and get feedback. Start working on start,stop buttons and headlight	Completed	11/11/2015
9	11/13/2015	11/20/2015	Testing substantial self driving capability of the car
10	11/21/2015	11/30/2015	Complete integration, Debugging and Fine tuning
11	12/1/2015	12/5/2015	Final Validation

Geographical Controller Schedule

Sl. No	Start Date	End Date	Task	Status	Actual Completion Date
1	09/27/2015	10/07/2015	Ordering Parts and understanding each module	Completed	10/11/2015
2	10/07/2015	10/13/2015	CAN Communication with other boards and understanding each module	Completed	10/13/2015
3	10/07/2015	10/30/2015	Algorithm for distance and heading calculation and coding	Completed	10/30/2015
4	10/14/2015	10/20/2015	Interfacing of compass(I2C) and GPS (UART) with SJONE board	Completed	10/20/2015
5	10/20/2015	10/30/2015	Coding, Compass Calibration,GPS Calibration	Completed
5	10/25/2015	11/15/2015	Individual unit testing	Completed
6	10/30/2015	11/30/2015	Interfacing with Android, Master and IO controllers
7	10/30/2015	11/30/2015	Integration Testing,On Car Calibration	First level of On Car Calibration Completed

Master Controller Schedule

Sl. No	Start Date	End Date	Task	Status	Actual Completion Date
1	09/30/2015	10/6/2015	a) Design of Algorithm and Architecture for Master Module. b) Setup of CAN communication between two controllers.	Completed	10/6/2015
2	10/7/2015	10/13/2015	a) Development of CAN message system for Android, Sensor and GPS, I/O reception. b) Decide about periodic function frequencies that’ll be handling different modules.	Completed	10/13/2015
3	10/14/2015	10/20/2015	a) Development of driving,stopping and obstruction avoidance algorithm for motor. b) Implementation of LED Display to display number of messages on CAN bus. c) Implementation of turning algorithm as per the data received from the Geo Controller.	Completed	10/20/2015
4	10/21/2015	10/27/2015	a) Designing of Kill switch with the help of Motor, I/O and Android. b) Design the system to restore the last known configuration. c) Implementation to reset modules if the CAN bus reaches BUS off state.	Completed	10/27/2015
5	10/28/2015	11/3/2015	a) Design of Head Light functionality with the help of Sensor module. b) Implementation of log files saving to SD card.	Completed
6	11/4/2015	11/10/2015	a) Integration of all the modules with Master module and check it after combining everything. b) Probable implementation of additional features.	On going
7	11/11/2015	11/17/2015	a) Refine the work done earlier.Change areas that need a change. b) Test the Master module while all the modules are integrated together and list down modifications and additions to be done.
8	11/18/2015	11/24/2015	Testing of system and specially making sure that last week’s shortcomings are taken care of.
9	11/25/2015	12/1/2015	a) Final testing of individual modules. b) Testing the self-driving capability of the car.
10	12/2/2015	12/8/2015	Final working on the shortcomings in the previous week.
11	12/9/2015	12/15/2015	Final Testing of Car.

Communication Bridge & Android Controller Schedule

Sl. No	Start Date	End Date	Task	Status	Actual Completion Date
1	9/29/2015	10/06/2015	Ordering bluetooth module and setting up android dev enviornment	Completed	10/06/2015
2	10/06/2015	10/13/2015	Implementing basic UI with Start and Stop buttons and testing bluetooth module	Completed	10/12/2015
3	10/13/2015	10/27/2015	Integrating android app with bluetooth module and SJ One board	Completed	11/01/2015
4	10/27/2015	11/03/2015	Establishing communication with other modules using CAN and testing Prototype	Completed	11/07/2015
5	11/03/2015	11/17/2015	Enhancing UI features with Google Maps and display of sensor data from different modules	Ongoing
6	11/17/2015	12/01/2015	Setting up Communication with GPS and Master and prototype testing
7	12/01/2015	12/08/2015	Final app testing

Parts List & Cost

Give a simple list of the cost of your project broken down by components. Do not write long stories here.

Design & Implementation

CAN Communication Table

Sr. No	Message ID	Message function	Message Data	From	To
High
1	0x220	Motor Control (Direction Control- Straight, Left or Right Level of Direction-Level 0, Level1, Level 2 Motion Control- Stop, Forward or Reverse Speed Control - Stop, Level1, Level2 or Level3)	Byte[0] -> Direction Control Byte[1] -> Level of Direction Byte[2] -> Motion Control Byte[3] -> Speed Control	Master	Motor
2	0x010	Kill Message (User request to stop the car under emergency)	Control Frame. No data bytes.	Android	Master
3	0x020	Kill Message (Master request to stop all controllers and reboot under emergency)	Control Frame. No data bytes.	Master	All
4	0x030	Stop (User request to stop the car)	Control Frame. No data bytes.	Android	Master
5	0x040	Stop (Master stops the motor)	Control Frame. No data bytes.	Master	Motor
6	0x210	Sensor Data (Distance in cms)	Byte[0] -> Forward Distance Byte[1] -> Left Distance Byte[2] -> Right Distance Byte[3] -> Back Distance	Sensor	Master/Motor-IO
7	0x230	Total Distance to Travel	Byte[0-1]	Android	Geo
8	0x240	Send Checkpoints	Byte[0-3] -> Latitude Byte[4-7] -> Longitude	Android	Geo
9	0x250	Distance (Distance in foot)	Byte[0-1] -> Final Distance remaining Byte[2-3] -> Checkpoint distance	Geo	Master
10	0x260	Turn Angle and Direction	Byte[0] -> Turn Angle Byte[1] -> Direction (1-Left,2-Right)	Geo	Master
11	0x270	Run and Pause Command	Control Frame. No data bytes	Android	Master
12	0x280	Heartbeat Message	Control Frame. No data bytes	Motor	Master
13	0x281	Heartbeat Message	Control Frame. No data bytes	Geo	Master
14	0x282	Heartbeat Message	Control Frame. No data bytes	Android	Master
15	0x283	Heartbeat Message	Control Frame. No data bytes	Sensor	Master
Medium
16	0x410	Destination reached. (Stops the car when destination is reached)	Control Frame. No data bytes	Master	All
17	0x420	Battery Status	Byte[0-1]	Sensor	Master/IO
Low
18	0x610	Boot Request	Control Frame. No data bytes	Master	All
19	0x620	Boot Reply (Date and time will be sent to Master)	Byte[0-4]	Motor-IO	Master
20	0x621	Boot Reply (Date and time will be sent to Master)	Byte[0-4]	Sensor	Master
21	0x622	Boot Reply (Date and time will be sent to Master)	Byte[0-4]	Geo	Master
22	0x623	Boot Reply (Date and time will be sent to Master)	Byte[0-4]	Android	Master
23	0x630	Boot Status (Enable the map and run button in Android)	Control Frame. No data bytes	Master	Motor-IO/Android
24	0x640	System Start	Control Frame. No data bytes	Android	All
25	0x650	Source Co-ordinates	Byte[0-3] -> Source Latitude Byte[4-7] -> Source Longitude	Geo	Android

Car Framework and Components

The RC car, Traxxas Stampede, in its raw form consists of a Titan 12T 550 Brushed DC motor, a Servo motor, an XL-5 ESC (Electronic Speed Control) unit, battery and a pre-programmed wireless receiver and controller. The Battery used in the RC car is an 8.4 V, 3000 NiMH from Traxxas. The wireless receiver gets commands from the remote control and drives the motors accordingly, but the DC motor can be controlled only through ESC.

The ESC (Electronic Speed Control) unit is an electronic module, which receives PWM signals from the controller and varies speed and direction of the DC motor and also acts as dynamic brakes. ESCs are often used in RC models. The ESC has the capability to provide dynamic braking depending on the mode in which it is being operated.

Motor and I/O Controller

Hardware Design

Motor Module

The motor module comprises of a servo motor for the direction control and a DC motor for speed control. The servo motor helps the car in turning left and right where as the DC motor on the other hand helps the car move forward and backward. The motor used in the project is a brushed motor. Conventionally, brushless motors are faster and more efficient than brushed motors. But, the reason for selecting a brushed motor over a brushless motor is that we employ a dedicated battery for the motor such that we do not have any issues with power and efficiency. Moreover, we need not operate the car at high speeds.

The initial task in the motor module is to find the operating ranges of the motor so that we get to know the output signal range and frequency from the SJONE board which would be replacing the pre-programmed controller. The simplest way to find the operating ranges of the motor is to tap and analyze PWM signal that is being supplied to the motor over an oscilloscope. The results as shown in the below pictures indicate that the operating duty cycle of both the motors lie between 10% to 20% and the frequencies at which the motors operate is 100Hz.

IO Module

The IO module Consists of a 4 line * 20 characters serial LCD. Data from GPS and sensor module is displayed continuously by refreshing it every second. SJ one board communicates with LCD through UART. GPS data :-

• Latitude
• Longitude
• Final distance remaining

Sensor data:-

• Left sensor reading
• Right sensor reading
• Front sensor reading
• Rear sensor reading

Additionally, IO module controls lighting up headlights/taillights based on the direction of the car movement.

Hardware Interface

LCD unit requires 5V power supply for its working. The VCC and Ground pins are connected to common power supply lines that is used to power up all the boards. The Rx pin of LCD is connected to TXD2 (p2.8) pin on SJ one board. Two of the GPIO pins p2.6 and p2.7 controls the headlights LED’S and taillights LED’S respectively.

Sl. No	Pin on IO Module	Pin on SJSU One Board	Purpose
1	Vcc	Common power supply	5V for LCD
2	Ground	Common Ground	Ground for LCD
3	Rx	P2.8(TXD2)	Receive data from SJone board through UART
4	Headlight LED’s(2)	P2.6	Turn on headlights when car is moving in the forward direction
5	Taillight LED’s (2)	P2.7	Turn on tail-lights when car is moving in the reverse direction

Software Design

IO Module

LCD communicates with SJ one board through UART. The UART port is configured to operate at the default baud rate of 9600 bps. “FO” character is sent to initialize the UART port after a delay of 100 ms, upon powering up the board. The display unit responds after 100 ms. Now the LCD module is configured and can receive further messages to display on it. Data from modules such as GPS and sensor are received continuously through CAN. It is decoded, converted into proper format and displayed on the LCD periodically.

Implementation

“Can receive” function is called in periodic scheduler 100 Hz task. This function lets the Motor/IO module receive CAN messages from other modules connected to it. CAN set up filter function has been used to accept only essential messages required by this module. Based on the CAN message identifier, corresponding action is performed. These are the CAN messages required by the motor/IO module.

CAN MESSAGE ID:-

• 0x210 – Sensor data
• 0x220 – motor control message from master
• 0x240 , 0x250 – GPS data

Data from sensor and GPS modules are stored in global message buffers. Sensor data is 8 bit whereas GPS data ranges between 16-32 bits. These integer values are converted into character type and then sent to LCD through UART. LCD display function is called in 1Hz periodic scheduler task. Thus Sensor and GPS data get displayed on the LCD every sec.

The 3D design used as a support for mounting the LCD is shown below:

3D design for LCD mounting

Master Controller

As the name suggests, it is main controller on the car which interacts with all other controllers over the CAN Bus to achieve real-time functionality. Basic function of the Master Controller is to receive data from Android, Geo and Sensor Modules and develop the algorithm to drive the car autonomously based on the received data through the Motor Controller.

Hardware Design

• RC car was the basic infrastructure that was required to implement the project.
• CAN Bus with five SJone controller boards was integrated on General purpose Printed Circuit Board (PCB).
• Sufficient power-supply ports and external pins were provided to each controllers.
• Flat Ribbon Cables were used to reduce circuit complexity arising from external connecting wires.

Software Design

• Master Controller uses FreeRTOS environment to achieve its functionality.
• It uses Periodic Scheduler Task provided by Preet at its core to communicate with all other controllers.
• The functions of the Periodic Scheduler Task were used in a customized manner to transmit/receive the messages at specific intervals of 1Hz,10Hz,100Hz and 1000Hz.
• File logger function was used to log the real-time data onto SD card which was used for debugging purpose.
• Can Message structure of 11-bit id was implemented to send and receive CAN messages over the CAN Bus.
• CAN acceptance filter was set-up to receive messages specific to Master Controller from the CAN Bus, since it is the broadcast Bus.

Software Implementation

• Master Controller starts with initialization of CAN Bus and setting up reception filter from the main() function.
• The Periodic Scheduler Task then takes over to implement the actual functionality of the Master Controller.
• CAN_is_busoff() was used at an interval of 10Hz through periodic scheduler task to check if CAN bus was working continuously.
• The basic flow of control is as follows:

Sensor Controller

Sensor controller consists of sonar and ultrasonic sensors that are inter-connected to the SJOne board and CAN bus. The sensors detect if there is any obstacle around the car and report the distance of obstacle.

Hardware Design

Hardware design consists of four sensors connected to ports of LPC1758. The sensors in front, right and left direction are MB1010 sensors while the one at back is HCSR04. The sensors are connected to +5V to achieve the highest beam pattern that is available. The LV MaxSonar EZ detects objects from 0 inches to 254 inches and provides sonar range from 6 to 254 inches with 1 inch resolution. Objects from 0 to 6 inches are reported as 6 inches. Sensor operates at 42KHz. The sensor reports output formats in from of pulse width output, analog voltage output, and RS232 serial output. We have selected pulse width output.The sensor will continually measure range and output if RX data is left unconnected or held high. If held low the sensor will stop ranging. We have commanded a range reading by triggering high for 20uS. Below are the timing diagrams for the sensor

Timing Diagram for LV MaxSonar EZ Sensor

MB1010 Sensor

HCSR-04 sensor is a ultrasonic ranging module which detects obstacle from 0 to 400 cm. It is a four pin module – Vcc, trig, echo and Gnd. It includes transmitter, receiver and control circuit. The sensor operates at 40 KHz.It Requires 5V 15mA power supply. When a short 10uS pulse is provided to the trigger input, the sensor will transmit out 8 cycle of ultrasonic burst at 40kHz and makes the echo pin high.The Echo pin is lowered to logic low when the ultrasound burst is reflected off a distant object.To obtain the distance, measure the width (Ton) of Echo pin. Time = Width of Echo pulse, in uS (micro second) Distance in centimeters = Time / 58 Distance in inches = Time / 148 Or you can utilize the speed of sound, which is 340m/s

Working-of-HC-SR04-Ultrasonic-Sensor

HCSR-04 Sensor

The 3D design used as a support for mounting the sensors is shown below:

3D Design for Sensor mounting

Geographical Controller

Geographical Controller consists of GPS and Compass module. GPS module is used to track current position of car, find bearing angle of destination with respect to north and compass module used to know heading of car with respect to north. Difference between heading and bearing gives us turn angle which car have to take to reach destination from current position.

Hardware Design

Schematic

Schematic

SparkFun Venus GPS with SMA Connector
SparkFun Venus GPS uses Skytraq VENUS634FLPx IC. The Venus638FLPx outputs standard NMEA-0183 or SkyTraq Binary sentences at a default rate of 9600 bps which is adjustable to 115200 bps, with update rates up to 20Hz. We configured this module with update rate of 10Hz and 38400 bps UART rate. Module outputs GGA, GSA, GSV, GLL, RMC, VTG, ZDA NMEA standard messages which can be configures to as per our requirements. We configured it to give only GGA messages. GGA message format is shown below.
For configuring GPS modules to UART rate 38400 bps, 10Hz update rate and only GGA message at output, below binary commands are used.

GGA Message Format

Binary Configuration Commands

SparkFun Venus GPS with SMA Connector and Antenna

HMC5883L

HMC5883L

Software Design

The GPS communicates with the SJOne board through the UART and the Compass communicates with the SJOne board through the I2C

I2C Communication

The HMC5883L IC communicates to the SJOne Board through the I2C bus.
SJONE board -Master device
HMC5883L - Slave device
The I2C rate is controlled by the master and can be upto maximum 400 KHz. We have configured the rate as 100 KHz.

Master Transmitter Mode:
In this mode, the master writes to the slave registers.
The compass IC has a set of 8 bit registers to be initially configured for parameters such as device output rate, number of samples, device gain and operating mode. By identifying the device write address and register address, the values can be written by the SJONE board to the compass registers.

Master Receive Mode:
In this mode, the master reads from the slave registers.
The X,Y,Z registers of the compass can be then read by the SJOne board one by one knowing the device read address and register address.The register pointer will be incremented by 1 automatically after the current register has been successfully read.

Android Communication Bridge Controller

Hardware Design

The Communication bridge consists of establishing connection between car and the android phone which is established with the help of bluetooth module HC-05 connected to UART peripheral of SJOne Board. The UART pins on board are connected to bluetooth module in the manner shown in diagram. Once the connection is established between the car and the android phone and signals like 'Start','Stop' and 'Kill' are sent from android phone then they are received by the bluetooth and sent to SJOne board to be further broadcasted over CAN bus.

Communication Bridge

Communication Bridge

Testing

Describe the challenges of your project. What advise would you give yourself or someone else if your project can be started from scratch again? Make a smooth transition to testing section and described what it took to test your project.

Accuracy of GPS Module

GPS Module Coordinates on Google Maps

Accuracy of GPS module was tested by recording/logging coordinates received by module using LOG_INFO() function and plotting them on Google maps GPS Module Coordinates on Google Maps. GPS module was very much accurate we did not needed to calibrate it. It is observed that more number of satellite locks with module, greater the accuracy of coordinate readings.

Calibration of Compass

As any instrument has instrument error, so has the compass IC. The compass needs to be calibrated for accuracy. We undertook two levels of calibration.
1. Level 1 calibration was done without mounting the compass on car. The compass was rotated in its axis for 360 degrees and the error was identified for every 15 degrees (totally 24 zones) with the setup shown by the image in the left.
2. Level 2 calibration was done after mounting the compass on car.The car setup by itself had some tilt and we compensated it by means of adjusting the hardware mounting. Next, the motor’s EMI caused some magnetic deviation and the motor's influence was taken into account too. The car was rotated in its axis ( its axis being parallel to the compass axis) for 360 degrees with the deviation measured for every 15 degrees(totally 24 zones) with the setup depicted by the image in the right.

Set up for Compass Calibration before mounting on Car

Set up for Compass Calibration on Car

The deviation was not uniform for every zone. Using linear regression analysis technique, the relationship between the predictor variable - degrees and the response variable - radians was found in an ideal environment and the same was repeated several times for accuracy. The average of several such readings was taken as the final calibration value.

Before Calibration

After Calibration

Technical Challenges

Configuring GPS Module

We faced difficulty in configuring GPS module to sending only $GGA messages, 10Hz Position update rate and updating baud rate to 38400. Initially we were trying to configure GPS module via writing program for SJ One board and we were unable to do it. Later on we completed configuring by connecting GPS module directly to serial port and using GPS Viewer software. Through it we can directly configure GPS module without worrying about binary messages and checksum calculation.

Compass and Calibration

1. Initially the compass was mounted and tested on breadboard with its upper face downwards as the connecting strips are on the upper side. This made the compass produce incorrect values.
2. While reading the registers in compass HMC5883L, only x and y register values are needed. Hence we tried to read only those registers from the device. But it so happened that z register is in between the x and y registers and the read pointer did not advance after the x register was read and remained in the z register. This led to compass producing constant values.
3. While calibrating, the compass should be rotated on a horizontal plane with its axis of rotation fixed. Shifting the axis may result in incorrect values.
4. Having a robust hardware that does not cause any or very less tilt, will reduce the efforts of calibration as HMC5883L IC is not tilt compensated.
5. Calibration should be done in an environment which does not have iron , magnetic particles etc as those may cause magnetic deviation. As the motor module influences the compass with the generated EMI, mount the compass far away from the motor and calibrate with the motor ON to take account of the EMI generated.

Conclusion

Conclude your project here. You can recap your testing and problems. You should address the "so what" part here to indicate what you ultimately learnt from this project. How has this project increased your knowledge?

Project Video

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Project Source Code

• Git Repository
  

References

Acknowledgement

Any acknowledgement that you may wish to provide can be included here.

References Used

• GPS Binary Command Set
  
• GPS Logging Application Note
  
• Haversine Calculations
  

Appendix

You can list the references you used.