Problem at boot

[Tibo]

Hi,

I just bought a LIME2 board, but I can not manage to get it booting properly...

The board is alimented through the mini USB port only (is it sufficient ?)

I tried different images, and with two different screens.
The screens would detect the input, but then, nothing shows up...

The two LED on the Ethernet port are on, but I can't detect the board on the local network.

I don't understand what doesn't work, what I've done wrong... ^^' I just hope I didn't break it.

[LubOlimex]

Hello,

Powering A20-OLinuXino-LIME2 via the USB is insufficient. You need a 5V/1A power supply or better (5V/2A recommended). If you are looking to buy one, make sure the connector fits the board's power jack, the specification is here: https://www.olimex.com/wiki/PWRJACK

When testing with images test first with the one in this archive:

http://images.olimex.com/release/a20/A20-OLinuXino-bionic-base-20200417-140212.img.7z

then test with this one:

ftp://staging.olimex.com/Allwinner_Images/A20-OLinuXino/1.latest_mainline_images/bionic/images/Armbian_5.92.4_Olinuxino-a20_Ubuntu_bionic_next_5.2.21_desktop.7z

Let me know how it goes.

Best regards,
Lub/OLIMEX

[Tibo]

Hello,

I bought one, it works fine now.

Thanks !

[Skallwar]

I'm in the same situation as Tibo.

I'm trying to power my board via the USB OTG port as described in the User Manual.

@LubOlimex said: "Powering A20-OLinuXino-LIME2 via the USB is insufficient". Is it still true even for 5V/2A on the USB port?

[LubOlimex]

A20-OLinuXino-LIME2 board can't be properly powered from the USB port even if it is externally powered USB port. You need external power supply applied to the power jack (or a charged Li-Po battery applied to the 2-pin battery connector). I will explain why in detail below:

The USB current is limited typically to 500mA (and 900mA is the absolute maximum), no matter how powerful your power supply is, the AXP209 power management unit inside the board would limit the current available after it. There are separate inputs (power lines) for the power supply from the USB and the external power supply. 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 (http://dl.linux-sunxi.org/AXP/AXP209_Datasheet_v1.0en.pdf) - you would notice that the absolute 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). Of course, probably more than half of this current is required for the board itself (without anything extra attached)! 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!

As a reference when selecting a power supply check the links below, it should be 5V one with at least 1A of current (but 2A at 5V is recommended):

https://www.olimex.com/wiki/PWRJACK

2A supply: https://www.olimex.com/Products/Power/SY1005E/

1A supply: https://www.olimex.com/Products/Power/SY0605E-CHINA/

[Skallwar]

Thanks for the detailed answer

[JustinMJackson123]

Hi,

I just bought a LIME2 board, but I can not manage to get it booting properly...

The board is alimented through the mini USB port only (is it sufficient ?)

I tried different images, and with two different screens.
The screens would detect the input, but then, nothing shows up...

The two LED on the Ethernet port are on, but I can't detect the board on the local network.

I don't understand what doesn't work, what I've done wrong... ^^' I just hope I didn't break it.

Hello,

it works fine now.

Thanks !