~: Computerized wireless Robo-Vehicle :~
Abstract:- This is some what similar application that you have seen in “Remote controlled robo-vehicle”. The main difference is that now instead of remote now the computer will generate controlling signals through software written in VC++ which will be transmitted through RF transmitter attached to LPT port. Here again the term robo vehicle means a vehicle that can move in all four direction forward-reverse and left right. It could be toy car, a tank, JBC truck or anything. In this particular application I have used remote controlled toycar which is readily available in market.
The software drives the motor through keyboard and mouse means the direction of motor is fully controlled by both keyboard and mouse. One can move the motor in all direction like forward, reverse, forward-left, reverse-left, forward-right, reverse-right and also he can move the motor to upto some specific distance what ever entered by user.
Note:-the project is developed by Gamara Sanjay and Padia Kaushik the students of 4th sem EC.
________________________________________________
As usual the project is divided in two sections hardware and software.
In hardware section again there are two parts one is remote control and second is toycar. The remote control is joystick control of toycar which controls its motion in all the directions. Actually it’s a four channel RF transmitter which generates four different codes and modulates it over 27 MHz carrier. In the toycar circuit there is RF receiver chip which demodulates and decodes these codes and drives two different motors one for forward and reverse motion and second for left & right turn.
The remote control transmitter is connected with LPT port of computer and now the software will transmit the codes through this transmitter and it will move the toycar in desired direction. The same joystick control is given in the software also so that toycar will only move till the key (or mouse button) is pressed.
Hardware section:-
The schematic given below shows the circuit of computerized remote control for toycar.
The pin no. 2 to 5 of 25 pin D type connector are connected to inputs of ULN2003A
(datasheet) chip. The outputs of chip are connected with 4 coils of relays RL1 to RL4. The second terminal of coil is tied to Vcc. So when one applies high logic to input of ULN chip the current will pass through relay coil and relay will get energized. So its connections changes from C-NC to C-NO. The C-NO connections of each relay are connected with RF transmitter that will generate four different codes depending upon which relay is switched ON.
The four different relays are utilized for all the motions of toycar like forward, reverse, forward-left, forward-right, reverse-left and reverse-right.
The software program will switch on the particular relay(s) to move the toycar in desired direction. So now let us see software section
Software Section:-
The given figure shows the design of an application using VC++.
There are five buttons and one edit box. Their properties are set as under given in the table.
|
Sr. No. |
Item |
Property |
Setting |
|
1 |
Button |
ID
Caption |
IDC_FWD
&Forward |
|
2 |
Button |
ID
Caption |
IDC_REV
&Reverse |
|
3 |
Button |
ID
Caption |
IDC_LEFT
L&eft |
|
4 |
Button |
ID
Caption |
IDC_RIGHT
Righ&t |
|
5 |
Button |
ID
Caption |
IDC_GO
&Go |
|
6 |
Edit box |
ID |
IDC_TIME |
After completing the design attach a variable of int type with IDC_TIME of name m_id. Now you have to add function with each button. For this just double click on every button the message box appears. Leave all the things as it is and just click on OK. Add one more function with mouse move event. For this open class wizard and select dialog ID. In the function window scroll down to WM_ON_MOUSEMOVE. Click on it to add function. In the coding of each function you have to add codes to move the motor in each direction. As seen in circuit to move the motor forward one has to energize first relay RL1 and in same manner RL2 for left turn, RL3 for reverse and RL4 for right turn. So for all different motions you need these codes.
|
Motion |
Relay/s |
Hex Code |
|
Forward |
RL1 |
01 |
|
Reverse |
RL3 |
04 |
|
Forward-Left |
RL1 & RL2 |
03 |
|
Forward-Right |
RL1 & RL4 |
09 |
|
Reverse-Left |
RL2-RL3 |
06 |
|
Reverse-Right |
RL3-RL4 |
0C |
click here to view the code to edit all the functions.
