This is Kevin. It is radio controlled car with ability to perform full autonomous drive. My first goal was to make autonomous vehicle controlled by Arduino. So I bought cheap Chinese chassis. But it was terrible because I wasn't able to attach any component. So if I rode quickly, everything fell off. I tuned it, I've made brand new parts which eliminated problems I had and now I can concentrate only on programming. What you see is platform on which can be added many sensors or attachments. I've also made a nice little transmitter with full color display. Many of those parts were printed on 3D printer, including the transmitter, light bar, KEVIN's name and many other parts. Now I use KEVIN as a small maintenance-free pet.
Step 1: Parts Needed
This is the list of parts:
4 wheels driven chassis - can be bought here: https://www.banggood.com/4WD-Smart-Robot-Car-Chass...
L298n motor driver - 2 pcs, https://www.banggood.com/2Pcs-L298N-Dual-H-Bridge-...
HC-SR04 distance measuring sensor - 3 pcs, https://www.banggood.com/Wholesale-Ultrasonic-Modu...
Arduino DUE or clone - 2 pcs
Voltage regulator - 2 pcs, https://www.banggood.com/5A-XL4005-DCDC-Adjustable...
Nrf24-l01 wireless module - 2 pcs, https://www.banggood.com/NRF24L01-Wireless-Transce...
Breadboard - 2 pcs
Jumper wires - many
WS 2812b leds - 40 pcs, https://www.banggood.com/50Pcs-DC-5V-3MM-x-10MM-WS...
12V battery - should be around 1500 mAh
9V battery - common 9V battery
Joysticks - 2 pcs, https://www.banggood.com/PS2-Game-Joystick-Module-...
9V battery plug - 1 pcs
Display - 1 pcs, https://www.banggood.com/2_8-Inch-TFT-LCD-Shield-T...
Tools needed :
Step 2: Building the Chassis
Build the chassis, but not as seen on picture from internet. As you can see for this purpose is better off-road version. To make off-road version just attach motors to bottom.
Step 3: Mount Distance Sensors
Print all three holders. Straighten the pins on sensors so cables will go in right direction. Then screw it to lower deck of chassis. You don't have to drill holes, all are pre-drilled.
Step 4: Mount Wireless Module
Print all parts. Take cable holder top and bottom and insert jumper wires between them. Then screw it at the back of the chassis. There are two pre-drilled holes. Then take top and bottom cases, insert Nrf24-l01 module between them and tape it. Then connect module to cable holder. The wireless module is held only on jumper wires.
Step 5: Adding Motor Drivers, and Regulators
Take the motor drivers and attach it to the lower deck using double-sided tape, then connect motors to it. Out 1 and out 3 should be same polarity. Attach voltage regulators with double-sided tape. Set one to 3V and second to 5V with trimmer. I've used different, those in description will work as well. Attach only side part of breadboard as seen on picture. This will be 12V branch.
Step 6: Battery Holder
Print battery holder and attach it right after 12V branch with double-sided tape. Attach Velcro fastener to the battery holders and to the battery. Battery holders were designed to be cable holder as well.
Step 7: Cablework
To connect everything by using less cables you'll have to make your own. Make one cable which will go from battery to 12V branch. Make two cables 3 females to 1 male. These will be used to power hc-sr04 modules. Make six cables 2 females to one male. These will be used to connect both channels on motor driver.
Step 8: Rear Lights
Solder 7 ws2812b leds together as you can see on pictures. Try to copy ellipse on plexiglass. As a supply cable use copper cable, it's bendable and can be guided better.
Step 9: Complete Lower Deck
Use 3 female to 1 male cable to connect Vcc and ground pins on hc-sr04 modules. Use 2 female to 1 male cables to connect ENA and ENB together, In1 and In4, In2 and In3 on l298n module on both sides. Connect cables to every pin we'll need on upper "logic" deck, like 12V, 5V, 3V, trig and echo pins on distance measuring modules, control pins from motor drivers. Attach upper deck and put all the cables through holes.
Step 10: Upper Deck
Connect two breadboards as one and place it onto deck. Then you'll have to attach Arduino. You can use tape or drill holes and screw it. It's up to you. Then attach led bar which can be found here : https://www.instructables.com/id/Programmable-Led-... with bolts and nuts. To attach cable organizer you'll have to drill two holes. Then hide as much cables as possible in organizer and close it with Kevin sign. Notes about cable connections are in program. Wireless module and hc-sr04 must be powered from 3V branch. Arduino is connected directly to 12V battery via Vin pin.
Step 11: Transmitter
Print bottom part. Desolder pins from joysticks and solder wires in approx lenght 5cm. Use screws and bolts to attach joysticks.
Step 12: Adjusting LCD
We'll need to use Vin and 3V pins separately which are occupide by LCD shield. So desolder pins on Vin and 3V.
Step 13: Power Cable
Solder switch on ground cable of 9V battery plug. This will be used to switch power on transmitter.
Step 14: Put Everything in Case
Connect red wire of battery plug to Vin and black wire somewhere to ground. Wireless module is connected to 3V sa well as joysticks. Attach display to Arduino DUE. Wiring of joysticks and Nrf24-l01 is specified in transmitter V1.6. Upload the code to Arduino.
Step 15: Close the Transmitter
Print front part, attach it to bottom. Before attaching glue the switch to the front part. While attaching watch the display, Arduino is not taped or screwed, only display will hold it. But it's enough. Then use screws to tighten it.
Step 16: Completed Transmitter
This is how well mounted transmitter looks like. Program I've upoladed is translated to English so don't be afraid of Slovak.
Step 17: Kevin Is Completed
Kevin is now ready to serve as a retarded maintenance-free pet. With Kevin built you can concentrate only on programing. There is plenty of room for aditional sensors, there are two breadboards. There is also full-colored display which can be programmed to show what do you want. You can say this is only a chassis and transmitter on which you can build your own project and you don't have to bother with thinking-out how to place sensors or leds.
Third Prize in the
Remote Control Contest 2017