Using ultrasonic sensors front and rear, the Rover scans for threats within its exclusion zone. Once a threat is detected, it fires a shot with its laser canon, then approaches for the kill. For the kill shot, the IR sensor on the front scans for best angle for shot.
The big money is in military contracts ā¦ ha ha 
Yes, if you pause at second 42 you see the readings are ( 7 , 33 , 99 ) denoting Front Ultrasonic 7 cms , Front IR Reflectivity Reading of 33 , and Rear Ultrasonic 99 cms.
The lights donāt do anything on this particular project other than provide a little bit of āblingā.
The biggest problem with this project has been the relative crudeness of the SeeedStudio Ultrasonic Rangefinder. It has difficulty detecting targets that arenāt perfectly flat, and loses the target with regularity. Since I can view the live readings on my TM1638, I see what it is seeing at all times.
Most of my problem solving was working my way around those issues. Iām assuming a higher grade ultrasonic would have better performance, like the āpencil beamā you have listed hereā¦ robotshop.com/ca/en/devantech-srf235-pencil-beam-range.html
Before spending money like that, I need to do more research into if the performance in fact lives up to the promises. I know that in general you get what you pay for, so the SeeedStudio is good for āproof of conceptā which I have accomplished.
Iāve read all the data sheets and product info on all the ultrasonics on your site. Do you (anyone) have any independent experience with the ultrasonics that you could share?
Hereās the code if anybody wants to play with it.
This project ( and the previous wall hugging project ) was mainly to see what I could do with the ultrasonics.
I see what you mean about the IR. Iām about 4 hours into accomplishing the same functionality, but only using the IR as my detection and targeting method. Although its range isnāt as great, once I detect the target I have MUCH better luck keeping the Rover locked onto it. I like the way this is going already.
Iāll post that when I complete it.
Great work! I can fortunately / unfortunately see how tempting it is to make robotic weapons of war 
Do the numbers and lights have anything to do with the sensor input? If youād like to be a reference for DFRobotShop Rover code, you might post some of your code too.
Maxbotix have been around for quite some time and we have had very few customers indicate they had issues. If youāre operating indoors, IR is quite reliable.