I have purchased the Arduino starter kit for my son and we enjoy it. Trying to get him started at a young age. To be honest, I find it very interesting also and am learning with him to a certain extent.
I recently purchased a OSOYOO robot car because he is more interested in that:
The kit comes with a battery holder for 2x of the 18650 'laptop' batteries which connects them in series. The voltage reader with the kit says approx. 8.XX VDC or so when fully charged. The turning of the car is controlled on the car by having left and right side wheels turn opposite directions, IE: right side CW, left side CCW. The tires that came with the kit were creating too much friction and it would not turn (motors just made buzzing sound). I ended up removing the tires and running it on the plastic rims, turned fine due to they can now 'slip' on the hardwood floor in our home. Ran fine forward and backwards.
Next step in the project was to integrate infrared control. Got it up and working. I recall reading Arduino needs threshold voltage above 7VDC or so and was worried 8.XX is too close to that. I ordered a battery holder that is for 3x 18650, so voltage is now at 12.XX VDC. Motor shield and Arduino both power up fine, and infrared controller still works, but only to rotate the car left or right. When I use the button for forward or back on the infrared remote, all power 'shuts off' to Arduino and the motor shield (LED's turn off on shield and Arduino). The motors seem like they start to turn, then immediately everything powers off. Doesn't matter if I hold the car in the air or place it on the counter.
My question is why is the 12.XX VDC battery pack able to rotate the car left or right, but now it cannot go forward or back as it did with 8.XX VDC? Once I hit forward or back, all LED's shut off. Was moving forward and back with the 8.XX VDC batteries. Once I remove one battery (break connection) and then reconnect, all LED's turn back on and it will start turning left/right on command again but will 'shut off' when I try to command forward or backward. I tried to run Arduino off of the programming cable, and just run the motor shield with 12VDC, the LED's come on, but nothing happens when I press the buttons on the infrared controller.
Really appreciate any help you guys/gals can give. I have a couple ideas what may be happening but don't want to sound too stupid on my first post. Sorry in advance if my information is too spotty.