LIME2 does not power on with HDD

Started by SzosszeNET, January 26, 2018, 12:54:26 PM

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SzosszeNET

Anyone came across this issue? Would appear that if board does not power on if there is a SATA HDD attached. Tried multiple power bricks (even 3.1 A one) but the only way I can boot the board if I attach the HDD after the first few blinks on the board...otherwise no lights come up on the board.

LubOlimex

First make sure that you are using the SATA power supply connector to power the disk (people often use the LIPO bat connector). Then:

But when you attach the HDD at later time, does it seem to work (do you hear it spinning)? Is the disk then exploitable?

Can you upload a picture of your setup somewhere and share it so we can see some obvious connection problem?

How much does the HDD consume (it should be written somewhere on the disk)?

If nothing else seems to work, consider splitting the power supply line that goes to the LIME2 board and power the disk externally instead of trough the board.
Technical support and documentation manager at Olimex

SzosszeNET

Hello there,

Thank you for getting back to me. Certainly using the sata_5v port, it's next to the sata port. :)

If I give power to board without the HDD plugged in and the lights on it start flashing. At this point if I connect the HDD it indeed spins up no problem. Of the HDD is attached when I plug in the board nothing happens.
Well would need to create a new SD card to see that, I've moved boot and rootfs from the SD card to the HDD. So unfortunately even if I plug in the HDD later on it won't boot correctly as the scr references the HDD. As per the label the HDD needs 1A. As mentioned have tried multiple power supplies (was running this in the past couple weeks off a 2A one), but now even a 3A power brick would not make it boot.

Worth to mention not powering via the barrel connector but the OTG port.



LubOlimex

In short: powering the board via USB is the root of the problem, no matter how powerful your power supply is, the power management unit inside the board would limit the current available after it. Power the board via the power jack or use the 5VEXT pad at the bottom of the board (near 5V_E jumper). These are the only two places on the board suitable for applying 5V external power supply for "current hungry" applications of the board. The power jack is described here: https://www.olimex.com/wiki/PWRJACK

In more details:

The 5V USB power supply goes to VBUS pin of the power management chip AXP209, while 5V external power supply goes to ACIN pin of the same AXP209. There are different power input lines for a couple of reasons.

If you look at the table in "5. Electrical Characteristics" on page 6 of the datasheet of AXP209 (here: http://dl.linux-sunxi.org/AXP/AXP209_Datasheet_v1.0en.pdf) - you would notice that the maximum current available from AXP209 when power supply is supplied on VBUS is 900mA (no matter how much current you have available, AXP209 would output no more than 900mA). In the same table you also see when the power is instead provided on the ACIN pin of AXP209 (e.g. when powered via the power jack) - the typical current available is 2500mA!

Refer to the schematic to make a better sense of the explanation above.

Best regards,
Lub/OLIMEX
Technical support and documentation manager at Olimex