How to boot into u-boot command line?

yacca · August 14, 2018, 9:44am

I setup the serial debugging tool and run kermit with the following output:

Connecting to /dev/ttyUSB0, speed 115200
Escape character: Ctrl-\ (ASCII 28, FS): enabled
Type the escape character followed by C to get back,
or followed by ? to see other options.
----------------------------------------------------

But I didn’t see any other output below this when I boot the VIM2 by pressing the power button or by WOL.

What’s going wrong? Thanks!

numbqq · August 14, 2018, 9:59am

Hello yacca,

Please make sure the connection is right.

yacca · August 14, 2018, 10:25am

I think the connection is correct.

numbqq · August 14, 2018, 10:28am

Hi yacca,

Have you connect the HDMI cable to a screen? Does the VIM2 bootup successfully?

yacca · August 14, 2018, 10:34am

Yes, I can start the preloaded Android system successfully. I also enabled the WOL in Android and it works too.

balbes150 · August 14, 2018, 11:13am

Wrong connected contacts. Use only 3 contacts. Rx Tx GND

yacca · August 14, 2018, 11:42am

I used these 3 pins at the beginning and got the same result as that with VCC pin.

numbqq · August 14, 2018, 12:35pm

Hello yacca,

Does your USB to TTL convertor works well? Have you tried other convertors?

Thanks.

balbes150 · August 14, 2018, 1:13pm

Try swapping the Rx and TX pins. Very often they are written on the Converter “Vice versa”.
Check your TTY settings for programs.

yacca · August 15, 2018, 3:11am

It works after I swapped the RX and TX pins. Thank you!