I have a BBB and it works quite well however when I power it over the Barrel connector or over the vdd pins rather then use the usb connection it doesn't automatically boot. When I put the barrel connector and usb in at the same time and then remove the usb it continues running. This is running on ubuntu arm. I have tested that the power supply is between 4.95 and 5.04 V and is capable of sustaining this to just over 1 Ampere

Edit it appear the BBB does boot when supplied with 4.7 V lab power supply at ~0.4A power consumption. So that suggest something is wrong with the power supply. But how do I test it seeing I was able to verify that it can supply 1A at 5V.

This power supply works by feeding a 12V battery into a step down to convert it down to 5V if that matters. power-supply power linux beaglebone-black beagleboard

  • $\begingroup$ What's the amperage of your non-usb power supply? (Barrel and Vdd) $\endgroup$ Jan 27, 2015 at 16:54
  • $\begingroup$ max 1A/ 4.95-5.05 V $\endgroup$
    – Thijser
    Jan 27, 2015 at 16:55
  • $\begingroup$ I'd recommend trying a 2A power supply. $\endgroup$ Jan 27, 2015 at 16:59
  • $\begingroup$ But the BBB doesn't normally use more then 0.6A maximum and can be powered over usb (max 0.5A) $\endgroup$
    – Thijser
    Jan 27, 2015 at 17:00

1 Answer 1


Why do so many people keep "Underestimating the complexity of power supply design"?

I'm sure that you already know that every digital electronic device pulls a very brief (transient) surge of power when it is first plugged in and turned on -- at much higher current and power levels than the steady-state current and steady-state power during normal operation.

I'm guessing that your 12V to 5V power supply limits its output current.

Switching-mode power supplies, such as the one on the BeagleBone that converts that 5V to the even lower voltage used by its CPU, often interact badly (latch up) with current-limited power supplies during the start-up transient.

Have you looked at the BeagleBoard FAQ, which says "The power adapter is required to provide 5V ... at least 2A (or 10W) is recommended"?


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.