We have fixed two light sensors on fore side on the robo. The principle of sensors is that black colour will normally observe the light where other colours will normally reflects the
lights light source is fixed down ward Ld1 ,a white led reflected light will fall on the ldr if the light is more the resistance of the ldr is normally low and transister remains in cutoff state
When the robo moves on the black road , the light reflected is less and the ldr resistance is increasd, vr1 forms a potential driver along with ldr due to increase in resistance the base voltage on t1 will rise to conductionlevel and transister will go into on (conduction)state.
Resulting it’s collector which was getting high logic from the default microcontroller pin will become low. This low logic detection confirms that the robo is on the black road if the robo is our of the black road this logic will become high and it indicates off-road. Depending upon the left or right sensor robo will move towards right or left direction in order to stay on road out put from both the sensors shoul be low when the robo is on the road.
Based on the input of the sensors will move in forward direction left or right direction
We have also added head light, back light.. These lights automatically comes on while robo is in movement.Pin no 16 of u1 is connected to pino 5 of u2 out put of u2 at pin no 16 enebles the motor driver ic pin no 1 and 9 on u3 .pin no 17 and 18 of microcontroller u1 controls the motor m1.pin no 14 and pin no 15 of u1 controls the motor m2 when both pins high or low nothing heppens motor will not turn
Construction: Solder all the parts provided in the kit properly. First connect the jumper wires(links) before you solder the ic sockets. Donot solder integrated circuits directly on the circuit board , it may damage the ic since you my not be experianced soldering person. So solder the ic sockets first on the circuit board. Solder smaller components first like resistance and disk capacitors, assemble the complete kit one by one. Please make sure that there are no short circuits left on to the circuit board. Check the power supply at all the sockets mounted on circuit board it should be 5 to 6.5v dc.