How do I get the board to power up with an external power supply – 5 volts, without using the USB? I tried putting 5 volts into the boards 5 volt connector and that did not work, neither did it work after pressing the power button. I want to supply 5 volts to the P9 header 5Vdd pins and ground – so that the board runs independent of a USB connection.
What am I doing wrong??
Kevin c
Which board are you using?
5vDC into the barrel Jack of the BBB should work, unless your using a different board…
Regards,
I am using the Black Wireless version. Putting 5 volts into the 5 volt connector did not work. Putting 5 volts into pins 5 and or 6 of P9 with a ground connection on pins 45 and 46 did not work either. I got it to work by first powering it up using USB, then turning it off with the on board power switch. Then when I applied 5 volts to either the connector or the pins on header P9 it finally powered up.
This morning it is back to doing what it did at first and will not power up when I apply 5 volts to the header pins. Once I apply 5 volts to the connector it power on and then it will power up from the header pins.
Perhaps the on board intelligence power supply has some kind of problem? I have a second board and I will try that one later today.
Well,
I powering always with 5volts on pin 5 and gnd on pin 1.
Have you had something connected to your beagle ? A servo or something?
Interesting.
I have two boards, fresh out of the bag, never been used for anything, and neither will power up using those pins or the alternate ground pins on the bottom of P9 either. But when I apply 5 volts to the 5 volt connector it comes right up and runs. It is like there are diodes on the pins 5 and 6 that prevent flow from my power supply but allow it to come out of those pins when it is powered from the connector.
I am using a very good quality power supply, B&K 9110, adjusted to 5.00 volts and 1.5 amps.
Now response at all when connected to pins 1 and 5 – and I have checked the polarity and checked the voltage with an external DVM.
The two boards only power up when using the external 5 volt connector or a USB cable.
I have exactly the same issue. The beaglebone black wireless does not boot up using the power on pin 5 and pin 1, or power jack.
It also does not boot up using the USB on a powered USB hub. The only way that I can get them to boot up is connecting the USB to my PC. These are new clean boards, never been touched before.
This is a firmware issue as these boards should just boot up if power is supplied to them.
Any suggestions would be great.
I would put a scope on the power input and watch the rise, fall and overshoot on the output from the B&K bench power supply.
The BeageBone Black has a PMIC chip that has some tight power requirements, input rise time is 50 ms max, the maximum voltage is 5.5V and minimum is 4.5V or the PMIC chip will go into self protect.
If, when you turn it on, the Voltage overshoots temporarily above 5.5 Volts, as my B&K 1550 does, then the Beaglebone will not boot, because the PMIC went into self-protect.
I have personally been very disappointed in the Voltage control on the less expensive B&K bench supplies.
As an example, if you set my B&K 1550 to 5,0 Volts, current limit to 1.25 Amps, then short circuit the supply, such as might happen with a probe-slip, the current goes to 1.25 Amps, the Voltage to a fraction of a Volt, but when the short is removed, it overshoots to 8 Volts, before returning to the regulated 5.0 Volts. This will destroy many requlators that are specified for 6 Volts, for sure it will trip the PMIC into self protect if it does not destroy it.
I suggest that you get a different 5.0 Volt supply, not a variable bench supply, and re-run your experiments.
— Graham
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