Actually, VDD_5V is raw 5V power, connected directly to the DC power jack. It is absolutely possible to power the BeagleBoard this way, and I have several capes that do so and work just fine (the BeBoPr and K9) powering the 'Bone via VDD_5V.
The LED behavior likely indicates something is going wrong with booting the operating system. The easiest way to debug these issues is with a serial port cable, so you can see what's happening. As a guess, you may be tying some other pins (specifically the LCD_DATA lines) to circuitry and messing up the AM335x boot process. By changing the values on these signals at reset, you can determine if the CPU should boot from eMMC flash, SD card, ethernet, USB, serial, etc., so messing this up can easily result in a system that won't boot. Double-check the LCD_DATA lines, and get a serial debug cable so you can see what's going on. On 12/23/2013 3:05 PM, Daniel Metcalf wrote: > I am not sure you can power it that way. I am a newbie to beaglebone black > but checkout page 110 of 124. > Pin 5 of J9 is VDD_5V which is described as the following: > > *VDD_5V *is the main power supply from the DC input jack. This voltage is > not present when the board is powered via USB. The amount of current > supplied by this rail is dependent upon the amount of current available. > Based on the board design, this rail is limited to 1A per pin from the main > board. > > I believe it is an output from a regulator. > > You are going to want to connect to TP5 - BAT, TP8 - GND, TP6 - SENSE > > > > > On Mon, Dec 23, 2013 at 3:30 PM, José Luis Redrejo <[email protected]>wrote: > >> I've made a power supply to power my BBB, but whenever I connect it >> (to pins 5 & 1 of P9 connector for VDD & GND), the power led blinks >> for some seconds and then it is off. >> >> The output comes from a 7805CKCT, which can provide up to 1.5A. >> >> It's a typical power supply from a rectifier + capacitors + regulator. >> >> What does this "blinking" mean? any ideas of what is going wrong? >> >> Regards >> José L. >> >> P.S. The board works perfectly plugging it to a computer via USB >> >> -- >> For more options, visit http://beagleboard.org/discuss >> --- >> You received this message because you are subscribed to the Google Groups >> "BeagleBoard" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to [email protected]. >> For more options, visit https://groups.google.com/groups/opt_out. >> > > > -- Charles Steinkuehler [email protected] -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/groups/opt_out.
