Vermes
Advanced Member level 4
It is a vehicle controlled by bluetooth interface. Connecting to it can be done by a computer or a mobile phone. It has a built-in camera with the possibility of trading in two degrees of freedom: up-down, left-right.
Assumptions:
- create a turning vehicle that can ride in a rugged terrain
- control by interface of a big potential
- On-board camera, so the vehicle can be controlled from one place
- design the electronic part with the possibility of further development
Bluerider can be divided into two parts in terms of software:
- the program located in a vehicle on-board microcontroller
- soft installed on the phone/computer
Electronics:
The main part of the device is Atmega8 microcontroller, which performs all the control functions. A series of LEDs signalling the current state of the microcontroller outputs is in the control part of the vehicle. The signal from the camera is received by a device in the camera, which is connected to the computer through TV card. The transmitter is integrated with the camera, power supply voltage is 9V.
Communication module:
Bluetooth module BTM-222 allows serial communication RS232, used in this project. Those modules are powered by 3,3V, the whole control system is powered by 5V, so voltage converter (system 74HCT14) was applied. Thanks to it, the communication of the system powered by 3,3V with the system with voltage of 5V is possible.
Power system controlling the motors
A conventional system H-Bridge was used as elements that directly control the motors. It is a specific combination of transistors, which allows to control the DC motor turns right-left. In order not to increase the dimensions of the main printed board, L298N chips were used. They are dual H-bridges with a capacity of about 3A. Bluerider vehicle has two such chips in order to increase the scalability. There are four bridges, two of them are currently used.
The mechanical part
Wheels and drive system – two DC motors, each with a power of about 20W, from recycled parts, regenerated and mounted. The chassis was taken from a broken toy. Two right wheels are coupled together by means of tribes, the same with two left wheels. This solution greatly increases the maneuverability – even allows the vehicle to rotate around its axis. Turning is done by opposite direction of rotation of the left and right wheels, or turn only one side of the wheels, while the other wheels will not rotate.
Schemas:
Photos:
Video:
Link to original thread (attachment) – Bluerider - samobieżny pojazd sterowany przez bluetooth