Recently I came across a video about a guy building a remote bluetooth controlled arduino car and I was quite amazed. So I decided I want to build it too. I have no arduino or electronics experience at all other than being an IT professional.
So I bought the parts he used in the video (he advised a knockoff arduino in the description) After putting it all together the motors work through bluetooth (yay!). But the issue is that the batteries connected to the motorshield don't give power to the arduino at all (because the lights don't turn on).
When plugged in the laptop with the usb cable the arduino gets powered and the motorshield light turns on just a bit. But not enough to make the motors and bluetooth work.
So in short: USB powered: arduino works, motorshield light barely turns on, motors don't work, bluetooth lights go on, but is not emitting a bluetooth signal.
2x 18650 battery powered: motorshield light shines bright, arduino doesn't work, bluetooth lights don't flicker.
Both: everything works.
So for some reason the batteries connected to the motorshield don't power the arduino.
Video used: How To Make A Simple DIY Arduino Bluetooth Controlled Car At Home - YouTube
Circuit diagram:
Knockoff arduino:
jremington:
The ancient, weak, extremely inefficient L293D is a terrible choice for motor driver.
About half the battery power is wasted as heat, and it may not be able to handle the current required by the motors you chose.
Post a link to the product page or data sheet for the motors, as that information is needed to choose a suitable motor driver.
I used these. (They are the same ones used in the video).
But as I said, it works... just not how its supposed to. The batteries seem to only power the motorshield, instead of both the motorshield and arduino.
Triple check your wiring. There are two power supply connections to the L293D, logic and motor power. Connect the logic power to 5V. Use your multimeter to verify that voltages are present and have the expected values (if you don't have a multimeter, now would be a great time to buy one).
batteries ... don't give power to the arduino at all
Are you sure that the motor driver board is supposed to be able to do this? If so, there is probably a jumper setting that needs to be correct. Check the documentation for the board.
The product page states that motor has a no-load current of 150 mA, which means that it probably draws over 1 Ampere when starting up. The L293D is limited to 600 mA (0.6 Amperes) continuous per channel.
Since about 4V is lost in the motor driver to heat, try using 3x18650 or a 6xAA or 8xAA battery pack instead.
I found the issue, the jumper + the 2 pins for the jumper are defect or not soldered correctly. When shorting it with my screwdriver it kinda worked correctly.
So I have to fix that. Should I take the pins off and resolder it better?
