Hi guys

this is my second instructable and is based on the first which u can find here-link,

the first one was a bit raw and this one is a bit refined.

WHATS NEW!!

The wire hassle has been eliminated to a great extent.

better looking and more powerful four wheel drive.

circuit for car and remote designed in eagle which are attached in this instructable.

and....i don't know, there may be some more i leave it to you to find them out :).

Step 1: GET THE PARTS

copper clad board,acetone,sand paper,pcb drill,0.8mm and 1mm drill bits,some female jumper wires (red and black will be better),16 gauge wire,soldering rod ,soldering flux and soldering wire.

For the car you will need:

1.car chassis

2.4 geared dc motors

3. 4x 1000uf capacitors

4. ic ht12d

5.ic l293d (l293ne is preferred)

6.315mhz receiver

7.wheels for motors

8. 1x 51k ohm resistor for ht12d oscillator pins

9. LM7805

10. 2x 1N4007 diodes.

11.12v battery.

12. leds-white,blue and red or as you wise them to be, resistors-1k,51k,16pin and 18pin ic base, female burg strips,double tape,some nuts and bolts to get the chassis together.

for remote:

1. 2x dpdt switches.

2. ic ht12e.

3.315mhz transmitter.

4. 1x megaohm resistor for transmitter oscillator pins.

5. 1x red led and 1k resistor.

6. 3v coin cell x2(cr2032) and their holder.

7. two resistance with series resistance approx. 1meg.

7. female burg strips,18 pin ic base.

Step 2: SOMETHING ABOUT IC'S WE WILL USE-

we will be using-

1.HT12D

its a decoder ic and placed on car.

2.HT12E

Its a encoder ic and placed on remote.

HT12E AND HT12D WORK IN COLLABORATION WITH TRANSMITTER AND RECEIVER RESPECTIVELY.

3.L293D

its a very well known motor driver ic used to run motors through a separate power supply when it gets a signal from a microcontroller i.e a 5v control signal on its input pins.i recommend using L293NE because of its higher current rating of around 1A in contrast to 0.6A offered by L293D.

4.LM7805

again a well known ic ,its a linear voltage regulator which regulates input voltage to 5v at its output.

much on the above 3 ic's in my previous instructable-link,and i'm assuming you are well versed with using 7805.

Step 3: CIRCUIT FOR CAR AND REMOTE

The circuits were designed in cadsoft eagle ,i'm new to this software so if someone can give me some useful tips it will be appreciated:).

other thing is that we will be having a single layer copper board and some connection would be tough on the same layer so i used 16 gauge copper wires on top too to make connections.

schematic and board files of both car and remote have been uploaded in case u want to make some changes of your own. and for direct printing the pcb i have also uploaded the pdf file just open it up and print it on a glossy paper.there are many good text available on internet explaining pcb printing and getting it on the copper board so im not going into it.

one advice i will give is that first get the copper side of the board done and drill holes in it after that it will be easy to place the top print over the board with the holes helping to align the top side print with the bottom.

Step 4: Getting the Pcb Done.

1.cut the board to dimensions and then iron the print on copper side for few minutes,soak in water till its easy to remove paper.

2.fix the broken lines using a permanent marker.

3.now your pcbs are ready for a fecl2 bath(other chemicals are also available for etching process).

4.get rid of the ink from board to reveal the shiny copper tracks.

5.drill holes and now get ready to place the top print over the top of the board, use the holes you made to align the print and iron it to.

6.again soak in water to remove the paper.

7.now you are ready to solder your components.

Step 5: ABOUT THE CAR

SOME POINTS ABOUT THE CAR ARE AS FOLLOWS-

1.twist the motor wires and place a 0.1uf ceramic capacitor at their terminals this is done to minimize rf noise caused by them.

2.diodes were used to get the effect of using two power supplies from one battery,this is done to prevent circuitry from current spikes generated by motors.

3.a toggle switch is used in car to turn on/off the headlights.

4.cut the female jumpers into two and connect the wire end to battery and jumper head to pcb for supply.

Step 6: ABOUT THE REMOTE

SOME POINTS-

1.use an antenna to improve reception.

2.use any power supply you wish but greater than or equal to 5v.

3.initially i had in mind of using dip switch for address matching so you will see it in the remote but later i dropped this idea because of space restriction on car pcb.