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 wanted 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 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: https://youtu.be/Q36NbjPMV5k

Circuit diagram: The motor shield is directly on the arduino

Knockoff arduino: Arduino

L293D motor shield (I'm aware that the ground of the power isn't plugged in)

motorshield with bluetooth module connected to analog and +5 power and ground

Parts used:

  • Geekcreit UNO r3 ATmega16U2 AVR
  • L293D motor shield
  • Geekcreit HC-05 bluetooth
  • 4 TT motor
  • 2x 18650 3,7-4.2v 2200mah batteries

I really don't know what I did wrong, since I followed the video and did exactly what the person did. Maybe the batteries aren't powerful enough?

  • 1
    the yellow jumper is the first suspect ... remove it and short the pins with a screwdriver
    – jsotola
    Jan 3, 2021 at 19:39
  • @jsotola what would shorting the pins cause?
    – Yestli
    Jan 3, 2021 at 19:45
  • it would replace the jumper ... the yellow jumper itself may be missing the metal strip that shorts the two pins
    – jsotola
    Jan 3, 2021 at 19:57
  • That sadly didn't work.
    – Yestli
    Jan 3, 2021 at 20:28
  • 2
    After trying to short the pins again, i found out @jsotola was right. The jumper is a defect. It's working now
    – Yestli
    Jan 4, 2021 at 12:19

2 Answers 2


The problem was that the 2 pins on which the jumper sits, the jumper or the board was broken (idk exactly). I might've caused that myself by turning on the batteries + powering it through usb at the same time.

I bought a new L293D board then made sure I didn't connect usb power to the arduino while the L293D was sitting on top of it. I uploaded the code, then disconnected the usb, put the L293D on top, powered it all and it works like a charm!


Nice project. The batteries are connected to the motor power which is correct but the motor shield does not output voltage to the 5V system. Try connecting the batteries to the Vin on the board and all should work.

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