[beagleboard] Changing USB current limit in BB Black

The controller trip point is already set to 1300mA in UBoot for the default image we ship.

Yes it is safe to do that. We do it on all boards that ship.

It should be done in UBoot like we already do.

Now, if the PC cannot supply over 500ma, well, setting this current trip point to 1300mA does not do much good. So as long as you use the production uBoot, all is well.

If not, then I suggest that you just look at the uBoot source code and put it into that other UBoot that you may be using.

Gerald

The controller trip point is already set to 1300mA in UBoot for the default image we ship.

Yes it is safe to do that. We do it on all boards that ship.

Oh, thanks for the fast reply. I forgot to write I’m using debian wheezy. Your “native” Angstrom install does not starve, and now I understand the reason why.

It should be done in UBoot like we already do.

Now, if the PC cannot supply over 500ma, well, setting this current trip point to 1300mA does not do much good. So as long as you use the production uBoot, all is well.

I’m using an USB power supply. I have several of those, most of them can get to 1A; I have got also a 2.1A one.

If not, then I suggest that you just look at the uBoot source code and put it into that other UBoot that you may be using.

Sounds like an interesting hacking mini-project, since my knownledge about uBoot is near zero :-). I have already tried set it up in uEnv.txt, but it didn’t work (I intended to write 0x3E in the 0x01 register to up it to 1300, and after boot it was back at 0x3d).

Uboot can be fun for sure. No matter the distribution all should be using the latest UBoot. You might just try copying the one we ship over to your distribution and give it a try.

Gerald

Just one more question. Where can I find your uBoot sources? Are those the ones at git:``//git.denx.de/u-boot.git? I guess you use a patched version, since I can’t find the power setup there (I’m looking at include/configs/am335x_evm.h).

As I understand it, that is the correct link.

Gerald

I am probably doing something VERY wrong.

I have downloaded the u-boot sources and compiled them using the instructions I found here:

U-Boot Download

After compiling it (zero errors) I have copied MLO and u-boot.img to the boot partition in my SSD card. I have copied the suggested uEnv.txt file too…

… and the SSD card fails to boot. If I press the user button while powering the BBB, it just does nothing. It boots ok with the debian image u-boot. If I restore the distributed MLO/img files, it boots again.

So my u-boot build is wrong. I have no serial cable, so I just can boot “in the blind”. Any idea of what am I doing wrong?

(I guess my best chance is to get a console cable and check for error messages, but I won’t have one in a few days… :)).