[beagleboard] Beaglebone boot failures

Sounds like you may have a marginal power source issue. How are you powering the board?

Gerald

The Bone is the most picky product I've ever worked with regarding input
voltage. It would not run on a "regulated" 5 volt wall wart that output
5.2 volts under load. I went through my large box of warts and could
not find one that would reliably run the board.

So I bought a 5 volt 1 amp regulated wart. 5.1 volts would not reliably
run the board.

My solution was to take a 9 volt regulated wart, cut the positive lead
and insert an LM7805 voltage regulator and a couple of 1uF film caps in
the line. The BB draws enough power that a clip-on heat sink was
necessary for the regulator. I now have 5.00 volts at the board socket
with the connector plugged in and my Bone is as happy as clams in sauce :slight_smile:

John

Is it really the voltage? I’m not a beaglebone user, but to me it sounds more like a supply current issue. Thanks

Ryohei

2013年3月25日月曜日 hohle.paul@gmail.com:

Hmmm… The adaptor can drive up to 2A… Seems like more than enough current

2013年3月25日月曜日 Ryohei Nishimura nishimura.ryohei@gmail.com:

Dear Paul,

I just checked out the schematics for beaglebone and may have found out the reason.

According to the data sheet, the LDOs on TPS65217B can only support up to 200mA.

This is well bellow beaglebone peak current consumption of 370mA at kernel boot. This could be a bug.

http://www.tij.co.jp/jp/lit/ds/slvsb64e/slvsb64e.pdf

2013年3月25日月曜日 Ryohei Nishimura nishimura.ryohei@gmail.com:

The TPS65217B support a lot more than 200mA, like 2A. It is not a bug, otherwise 35,000 board would not be working at the moment.

The issue is more likely that the NCP349 is activating due to voltage spikes and shutting down.

Gerald

Hi Gerald

Please refer to pg 34 of the data sheet I attached to one of my emails. There are a lot of vdd’s so I can’t be sure but IOs seem to be driven by LDO3 or LDO4. Maybe I just misread it through

2013年3月25日月曜日 Gerald Coley gerald@beagleboard.org:

Paul

You didn’t actually dial up the output current to 6amps, did you? That would destroy your beaglebone!! Unless a fuse is implemented

2013年3月25日月曜日 hohle.paul@gmail.com:

The TPS65217 shuts down at 2A.

Also, the current of the LDOs only handle the processor. all external is handled by the external 500mA regulator.

Gerald

Your talking about vdd_3v3exp, i assume? It looks like it’s just connected to the expansion header. uSD seems to be driven by Vdd_3V3a…

2013年3月25日月曜日 Gerald Coley gerald@beagleboard.org:

Correct. Each LDO3 and LDO4 give a total of 400mA for the 3.3V on the A and B rails for the board use.

Gerald

Paul, Gerald

3.3v power domain of Omap is fairly low-power. uSD consumes about 100mA max. It seems like 200mA is enough for typical use cases.
http://processors.wiki.ti.com/index.php/AM335x_Power_Consumption_Summary

But voltage drop usually results from low current supply or it happens when the vdd is short circuited to gnd. Please check your expansion header paul…

2013年3月26日火曜日 Gerald Coley gerald@beagleboard.org:

AM335x is not an OMAP part.

Gerald

Ok. Cortex A8 part then. I’m a xm user :slight_smile:

2013年3月26日火曜日 Gerald Coley gerald@beagleboard.org:

I see. Title of this email string is “BeagleBone Boot Failures”.so I assumed that your response matched the title. DM3730 and the -xM it a different than the BeagleBone is a lot of areas…

Gerald