Step 1:

hi welcome to the third part of five part robot series.
this is the same transistor switch circuit that i have used in LIGHT FOLLOWING ROBOT AND LINE FOLLOWING ROBOT i didn't change anything from previous build

Step 2:

we just need to reposition the sensors

Step 3:

this is the circuit diagram.here you can see all connections.just swap motor connections.

Step 4:

time to assemble circuit board on our diy robot chassis

Step 5:

i am using a cardboard piece to hold sensors

Step 6:

Test it if needed adjust variable resistor. And enjoy.