16. Applications and Implications¶
This week’s assignment is to propose and define a final project “masterpiece” that incorporates as many aspects of our class as possible. I will develop an autonomous car that will map out a room.
What will it do?¶
For my final project, I wanted to challenge myself on the software and hardware side of things, rather than the CAD and mechanical aspects. My car’s main purpose will be to map out a room. It will have a distance sensor, a main board, a bluetooth chip to communicate to a computer, and motors to drive itself around. It will drive around a room, take input with the distance sensor, and store these points in its memory. It will then upload these points to a computer via bluetooth, which will map the points in a display.
Who’s done what beforehand?¶
In terms of the car design, previous student and teacher Will Rudolph created a drawing car. The car had a pen on the bottom compared to my distance sensor on the top, but it had many of the same components. I will keep his design in mind while workign on the mechanical aspects of my project. The Roomba vacuum cleaner has a similar function to my project, as it has the ability to map and store a room as it cleans.
What will you design?¶
I will design the electronics for my car, the main car body, and I will develop the software that controls the car. The electronics will include the sensor board, main board, and any breakout boards I need for motors or power. The car design will include casing for the electronics, a system to spin the sensor and sensor board by the stepper motor, and a way to balance the car (which will have 2 wheels). I will design my car after a Roomba since they have the ability to map rooms. The software will include manual control of the car, a way to calculate and upload the points, a way to track the car as it drives throughout the environment, and a way to display the points.
What materials and components will be used?¶
The electronics components that will be used include some darlington transistor breakout boards and chips for motors, a voltage regulator system, components for the ATMega328, and headers for an FTDI chip and bluetooth chip. The base of the car will likely be made from 1/8 plywood to minimize weight, while the frame will be made from 1/8 acrylic to improve the aesthetic. I will 3D PLA components for balancing the car and for holding motors and electronics in place.
Where will come from?¶
Most of the electronics components can be found in our lab, but I ordered some breakout boards and chips during input and output devices weeks from Pololu and Texas Instruments. The physical materials can be found in our lab- we have plenty of 1/8 plywood and acrylic as well as 3D print materials.
How much will they cost?¶
The electronics components in our lab were very cheap; the components used in my final board amounted to a few dollars. The breakout boards I ordered were more expensive; the motor driver boards were 3.50 each and the sensor breakout board was 12 dollars. The 1/8 plywood and acrylic will not be expensive either, and they will not cost more than 20 dollars.
BOM:¶
| Part | Total Cost | Source | Quantity | Other Information |
|---|---|---|---|---|
| 1/8 in plywood | 5.00 | link | 1 12 x 24 | This will be cut into the bottom and sides of the car |
| 1/8 in acrylic | 8.00 | link | 1 12 x 15 | This will be cut into the top for the car |
| VL53L1X TOF Sensor | 12.00 | link | 1 | Distance sensor with range up to 400 cm |
| DRV8838 Breakout Board | 7.00 | link | 2 | Breakout board to control the DC motors |
| 28byj-48 Stepper Motor | 7.50 | link | 1 | Motor to spin the distance sensor |
| Geared DC Motor | 6.50 | link | 2 | Motor for moving |
| HC-05 Bluetooth Chip | 10.00 | link | 1 | For networking between computer and car |
| 3.7V Lipo Battery | 22.00 | link | 2 | These will be connected in series to produce 7.4 volts |
| 1 kg 1.75mm PLA | 25.00 | link | 1 | This will be used to print out the different components inside the car |
| Total Cost: | 103 |
What parts and systems will be made?¶
There will be 2 main systems in my project. The main system is the car. This includes the physical aspects of the car, such as the frame and housing for electrical components, as well as the software. The other system is the computer and interface that will control the car. The two systems will be connected via an HC-05 bluetooth chip, which will transfer data between the systems.
What processes will be used?¶
I will use computer controlled cutting, 3D printing, electronics design and production, embedded programming, and interface programming to complete my project. I expect the most difficult task will be the embedded programming aspect due to the complexity of my task. I will laser cut the frame of the car out of 1/8 in wood and acrylic. I will 3D print different small components inside the car, such as electronics cases, pieces for balancing the car, and a case for my sensor board. The electronics design and production elements includes a main board with components for voltage regulation, FTDI and HC-05 headers, motor breakout boards, and the ATMega328 microcontroller, and a sensor board with an ATTiny1614 microcontroller and headers for the VL53L1X time of flight sensor. These two boards will be networked via software serial to input sensor data.
What questions need to be answered?¶
I will need to determine the best solution to the programming problems I am likely to face, including how to calculate, communicate, and display the data, and how to accurately keep track of my own location throughout the operation. I will also have to find a way to deal with slippage if I find it is an issue. If the motors slip while the car is running, it will no longer be able to keep an accurate location, so this could be a critical issue.
How will it be evaluated?¶
My project will be evaluated by how accurately it is able to map and display its enviroment, as well as how accurate and precise it is about its own location.