F17: Viserion

1 Viserion Team RC Car
2 Abstract
3 Objectives & Introduction
4 Schedule
5 Parts List & Cost
6 Process Control
7 PCB Design
8 Sensors Controller
9 Motor and I/O Controller
10 Master Controller
11 Bluetooth Controller And Android Application
12 Geographical Controller
13 Testing & Technical Challenges
- 13.1 <Bug/issue name>
14 Conclusion
- 14.1 Project Video
- 14.2 Project Source Code
15 References

Viserion Team RC Car

Abstract

Aim of this project is to build a self-navigating car. The car is divided into five modules. Each module consists of SJ One board as the main controller. The different modules in the car are master, sensors, geo, motor and bluetooth module. The car uses CAN communication protocol for communication between the modules.

The five modules of the car are :
Sensor Controller: This module detects obstacles in the driving path with the help of ultrasonic sensors.
Motor Controller: This controller drives the DC motor and Servo in the car.
Geographical Controller: This module assists the car in navigating to a destination with the help of location details provided by GPS and the orientation(bearing and heading angle) provided by the compass.
Bluetooth Controller: The controller uses Bluetooth to communicate with an Android application. Destination coordinates are provided by this module. The bluetooth module also displays important data like sensor readings, GPS coordinates and speed.
Master Controller: This module will collect data from all modules and direct the motor towards the destination.

Objectives & Introduction

Objectives

The objectives are as follows:

1.To detect and avoid obstacles encountered in the path.
2.To move at an appropriate speed depending upon the path requirement.
3.To use Bluetooth module to start/stop the car and display important data on the LCD.
4.To integrate gps and compass to make sure that the car navigates from source to destination.
5.To efficiently establish communication between all the modules using CAN protocol.
6.To reach a destination given by the Bluetooth module autonomously for a valid path.

System Block Diagram

Viserion Block Diagram

Team Members & Responsibilities

Master Controller

Aakash Menon
Omkar Kale

Geographical Controller

Ajinkya Mandhre
Aniket Dali
Jean Madassery

Sensor Controller

Miroslav Grubic

MOTOR & I/O CONTROLLER

Manoj Ramesh Rao
Pratap Ramachandran

BLUETOOTH CONTROLLER & ANDROID APP

Dheemanth Bangalore Vishwanatha
Pratap Kishore Desai

Schedule

Show a simple table or figures that show your scheduled as planned before you started working on the project. Then in another table column, write down the actual schedule so that readers can see the planned vs. actual goals. The point of the schedule is for readers to assess how to pace themselves if they are doing a similar project.

Legend: Motor & I/O Controller , Master Controller , Communication Bridge Controller, Geographical Controller, Sensor Controller , Team Goal , Team PCB, , Team Android

Week#	Start Date	End Date	Task	Actual Completion Date / Notes
1	10/09/2017	10/15/2017	Research previous projects wiki page, gather useful information. Discuss about roles and study data sheet of the required parts and list down minimum two parts for each required function. Setup Git and slack accounts and verify that access is provided to all the team mates.	Done
2	10/16/2017	10/22/2017	Design Hardware layout for the project, schematic shall identify all the modules, ports and the pins interfaced. Design sensor and motor board's schematic in eagle PCB. Design data flow diagram for all the software exchanges between the modules and the master. Complete DBC file based upon the design data flow diagram and share the file via GIT repo. Study about GPS and Compass calibration . Interface motor and drive using Preet's PWM driver API. Find different levels of speed and direction. Interface one sonic sensor to the sensor controller. Receive data and calculate distance. Write send, receive and MIA functions to be able to perform basic CAN communication. Study Android application software and approaches from previous projects and document the required features being provided by the application. Order finalized Components.	Done on time except PCB design was changed to only one PCB that will gather all controllers and have Can Bus on it.
3	10/23/2017	29/10/2017	Start interfacing received components to respective Nodes and do a superficial testing of components. Design GPS/Compass, Bluetooth and master board's schematic in eagle PCB. Identify and document best approach to calibrate Compass. Experiment on duty cycle suitable for direction and speed of the motors Communicate with Master and set speed and directions. Interface RPM sensor and calculate speed in KPH Interface all three front sonic sensor to the sensor controller. Apply filtering to get reliable data and send data to Master Controller. Document Android approaches and decide on how to design the app and fix the protocol to exchange data with Bluetooth module.	Done on time except Basic PCB design is done Filtering was not applied at this time
4	10/30/2017	11/05/2017	Interface RPM sensor and measure Speed.Maintain the speed based on feedback for uphill and downhill Improve the trajectory of the car using algorithm based on speed and directions Stress test front sensors in different environment conditions indoor, outdoor and compare data. Also change different angles for sensors and find best angles for most reliable data and maximum coverage. Start development of software modules for GPS and Compass modules and document the efforts and ways to test the algorithm. Test can bus communication by mounting master, sensor and motor modules and transmitting master related commands. Mount the parts on off shelf PCB for Demo 1 and verify the wiring connections and verify that CAR is ready for the demo,	Done on time
5	11/06/2017	11/12/2017	Finish Bearing Angle Calculation. Control the Car's speed on detection of obstacle. Interface back sensor, receive, filter and send data. All sensors should be working properly by now and master should be getting stable values even while car is on the move. Finish development of algorithm for Compass & GPS calibration and verify that the direction obtained from the modules with that of any off shelf smartphone's Compass. Car should now move without hitting "any" obstacle when powered on. Car should be able to take a reverse if required.	Back sensor was not yet interfaced. Filtering applied for front sensors.
6	11/13/2017	11/19/2017	Interface the LCD with micro controller and do basic display of text Prepare design and possibly try to finish 3D printing or figure out some other hardware solution for sensor mount for final car design. Share Gerber files with the PCB fabrication house and order 2 PCB. Design basic Android application UI, which can verify that the communication with BT module was successful or not Fetch current longitude and latitude values from GPS modules via BT app and send all the checkpoints to the destination via BT app and BT module to master and verify the link between GPS/Compass, master and BT module and Application is working as expected.	PCB design not finished yet. Back sensor interfaced.
7	11/20/2017	11/25/2017	Display speedometer, longitude and direction values Mount sensors on new/final hardware solution, position them properly and test again received data while car is in move. If the link between Geo, BT, master and Motor module is working, perform outdoor system testing.	PCB design finished and main PCB board ordered Still waiting for sensor mounts 3D printing to be finished.
8	11/26/2017	12/01/2017	Connect battery output to ADC channel and read back the battery parameters. Interface Head lights and turn them ON based on light sensor value. Implement automatic bluetooth connection between APP and bluetooth module	Sensor breakout PCB design and ordered
9	12/03/2017	12/08/2017	Display the battery parameters on LCD. Perform round 1 of system testing. Start documenting project report by collaborating artifacts produced during project development. Fix the bugs in system testing.
10	12/10/2017	12/12/2017	Perform round 2 of system testing. Start documenting project report by collaborating artifacts produced during project development. Fix the bugs in system testing.
11	12/13/2017	12/16/2017	Perform round 3 of system testing. Work on unfinished project report documentation. Fix the bugs in system testing.
12	12/17/2017	12/19/2017	Perform round 4 of system testing. Fix the bugs in system testing. Record a video to demonstrate project working and features. Complete Documentation of wiki page.
13	12/20/2017		Ready for Demo.

Parts List & Cost

Item#	Part Desciption	Vendor	Qty	Cost
1	RC Car - Traxxas 1/10 Slash 2WD	Amazon	1	$189.95
2	Battery - Traxxas 7600mAh 7.4V 2-Cell 25C LiPo Battery	Amazon	2	$143.26
3	Charger - Traxxas 2970 EZ-Peak Plus 4-Amp NiMH/LiPo Fast Charger	Amazon	1	$49.95
4	GPS - Readytosky Ublox NEO-M8N GPS Module	Amazon	1	$29.98
5	Bluetooth Module HC-05	Amazon	1	$8.99
6	IMU SparkFun 9DoF Razor IMU M0	SparkFun	1	$49.95
7	LV Maxsonar EZ0 Ultrasonic sensors	Robotshop	6	$158.7
8	RPM Sensor - Traxxas 6520 RPM Sensor	Amazon	1	$10.25
9	Jumper Wires	Amazon	1	$10
10	Acrylic Board MIFFLIN Acrylic Plexiglass 12 x 12	Amazon	1	$11
11	CAN tranceivers	Microchip Samples	30	Free
12	SJOne Boards	Provided by Preet	5	$400.0

Process Control

Progress Tracking

Unit Testing

code review

PCB Design

Sensors Controller

Based on research done on previous projects we decided to use Maxbotix EZ0 Ultrasonic sensors due to its reliability and cost. Four sensors total are used in this project. Three front sensors and one back sensor. They are all of the same type and manufacturer. Since they are triggered at different time, every 50ms, there was no need to use different sensor with different ranging frequency.

Hardware Design

There are two PCBs on car that are involved in wiring sensors, providing them with power and collecting data from them. “Main PCB” which is directly connected to Sensor Controller and “Sensors breakout PCB” which is mounted at the front of the car as close to sensors as possible to reduce wire length that goes through air. Two PCBs are connected with 12-pin ribbon cable. The sensors are powered with 3.3V and since we had only 5V power from power bank, we had to use 3.3V voltage regulator mounted on “Sensors breakout PCB”. Providing stable input voltage for sensors was also required because of unstable reading we were getting from sensors, caused by electrical interference. Our front sensors were interfaced by ADC, so stable input voltage was a must. Back sensor was interfaced by PWM since SJOne board has only three ADC pins.

Two PCBs connection

3D Printing Design

As a really important part of hardware design, 3D printing part was fun to make. After testing sensors on different heights from the ground and different angles we noticed that best results are when sensors are mounted as closer to the ground as possible, so we came out with our own design for sensors mount. Most important thing to consider when making design was to be able to adjust tilt of the sensors since we were receiving lot of reflection from the ground with temporarly mounts we used until we got the final printed version. So in order to satisfy that requirement mount is constructed from two parts, the stand and part that holds the sensor what gave us freedom to test sensors positioning during testing phase.

3D Design for Sensor stand

3D Design for Sensor mount

Final product

Sensor Mount in action

Hardware Interface

Sensors are interfaced with combination of GPIO, ADC and PWM pins. GPIO pins are used to trigger all sensors. Three ADC pins collect output from front sensors and PWM pin collect output from back sensor. Below you can see pin layout and schematics.

Sensors Pin Layout
Pin Name	Function
P2.6	Trigger for left sensor
P2.7	Trigger for right sensor
P2.8	Trigger for middle sensor
P2.9	Trigger for back sensor
P0.26	ADC input from left sensor
P1_30	ADC input from right sensor
P1_31	ADC input from middle sensor
P2_0	PWM input from back sensor

Sensors Connection Schematics

Software Design

Show your software design. For example, if you are designing an MP3 Player, show the tasks that you are using, and what they are doing at a high level. Do not show the details of the code. For example, do not show exact code, but you may show pseudocode and fragments of code. Keep in mind that you are showing DESIGN of your software, not the inner workings of it.

Implementation

This section includes implementation, but again, not the details, just the high level. For example, you can list the steps it takes to communicate over a sensor, or the steps needed to write a page of memory onto SPI Flash. You can include sub-sections for each of your component implementation.

Motor and I/O Controller

The motor controller is responsible for the steering and controlling the speed of the car. Both direction and speed of the car is controlled using the duty cycle of PWM signal. The speed of the car can be controlled by sending appropriate signals to the ESC connected to the DC motor of the car.