My project is based on 2 rover cars. The 1st car will go first, and if it finds any obstacle the second car has to be stopped automatically. Is it possible?
Yes it is possible!! why not!
Make two rovers which runs on two different Arduinos. Use a Communication medium, like RF I would suggest NRF24L01. These modules will act as a transceiver medium.
If the first car finds any obstacle (With help of Ultra Sonic or IR sensor) the information can be sent to another car using the RF modules. This information can be used to stop the second car.
With proper antenna the range of the RF modules can be extended upto 100m (Not tested practically though, but i have reached till 60m) . But, i guess it will meet your demands.
Thank you so much sir for your suggestions.
You are most welcome, All the best for your project!!!!