Project based off the Pocket Beagle - Boot Configuration Help

Hello, I am currently working on a project based on the pocket beagle. For my project, I had an experienced friend design and fabricate a custom board based on the pocket beagle to suit my purpose using the schematics and files on Github, nearly everything is identical except for the following changes: Removed all GPIO pins (unnecessary space), and replaced the microUSB connector with a male USB 2.0 connector(so that the board could be directly connected to a computer without a cable. Everything else was untouched and I used the exact same parts as the Pocket Beagle. I am trying to boot it with the latest Pocket Beagle Debian image however unable to do so because of the hardware change(I’m assuming). This is my first time working with something like this (I’m a software guy) so I apologize if I have a lack of knowledge about some aspects with regards to hardware. What do I have to do to be able to boot the Pocket Beagle’s Debian image on it? Originally I thought that because the hardware change was so minimal it should be able to boot the pocket beagle’s images. However, I realized that there is probably gonna be problems with regards to hardware id and such. Thanks, and I would appreciate any help.

If that were the only change and there were no hardware changes and the eeprom is configured, it should boot. Debugging hardware problems or anything before boot absolutely requires the serial connection on ttyS0. You’ll find plenty of posts here or elsewhere about such a cable.

I see, thank you so much for the information. I was going down the wrong path. This makes more sense. I was stupid to think the board would boot before any configuration of the PCB itself first. How do I configure EEPROM? Do I just need a serial connection to the board? I have absolutely no idea how to configure EEPROM. Can I also just copy the EEPROM configurations for the Pocket Beagle and if so where can I find it? Thanks so much.

Octavo has an app note about this. Basically you have to either program the EEPROM or modify the uboot to not care.

If you have the serial cable you can program the eeprom from within uboot. I never tried that, looks like fun.


Awesome thank you so much. This was exactly what I was looking for.

Ok so I followed the guide and made some progress. I hardcoded the device ID in u-boot so now when I boot all the user LEDs turn on momentarily but then turn off after one second. After they initially turn on they just turn off. Before hardcoding it, none of them turned on except the power LED. Does this mean that it is trying to boot but failed at some point? Also, one more thing I noticed is that when I plugged in the real Pocket-Beagle without a SD card Windows still recognized and allocated a COM port. However, when I plug in my version of the Pocket Beagle without the SD card, Windows doesn’t recognize it. Could this be the issue?

It’s basically impossible to diagnose further without a serial cable like I described above. But you can keep feeling blindly and might get lucky. I have no idea what the led indicates, but it changed something.

Good luck!

I strongly agree with Jim that the way for you to make progress is to connect up a serial cable. A FTDI FT232 USB to UART Converter is one easy way to do this. Only three wires (TX, RX and GND) from the pocket Beagle.

Once you have the serial output working, you could also try to boot something more simple off the SD CARD. You could try booting a simple app using TI starterware.


Ah I see thanks for the reply. However the problem I have is that I removed all the external pins including pins for power. Is there a way to set up a serial connection via the USB 2.0 interface?

Ah I see thanks for the reply. However the problem I have is that I removed all the external pins including pins for power. Is there a way to set up a serial connection via the USB 2.0 interface?

[Graham Stott] Yes, except that it would require a software driver which makes the USB a virtual UART. So that does not help you at all.

I presume you do not have access to any of the OSD335x pads. You may need your experience friend to redo the board and bring out the UART0 TX and RX to pads that you could solder on some wires to connect to the
FTDI FT232 USB to UART Converter.

I am not sure what else to suggest.

I see, thank you so much for your help! I'll look into it.