Hello,
i have bought a new DragonBoard 820c and followed the Getting Started instructions here. I made sure S1 is set ‘0000’ and plugged in HDMI, Mouse+Keyboard, and finally power (12V with 2000mA max).
When the board boots DS10 and BT glow blue and USER LED 1 flashes twice fast in a regular interval, but i get 0 screen output. The Monitor is a modern 2.560 x 1.444, 180hz display from LG and the HDMI cable is double checked. I already tried connecting in EDL mode and flashing as suggested here. But at the end i got no boot partition found instead of LUN1 is now bootable device. Do I need to provide a operation system via the SD Card? Any suggestions? Thank you.
I think the when the “USER LED 1 flashes twice fast in a regular interval” this is the heartbeat indicator. Basically this is a kernel load indicator and follows a heartbeat like rhythm (thump-thump-pause). The key thing is that if you see this pattern then it means that the kernel has booted.
Some ideas to debug are:
- Try different monitors if you have any (TVs can be used too if you have only one HDMI monitor).
- Try to access the device using the wired network connector. The device will use DHCP to get a network address from your router. If you are lucky the router has a admin page where you can see the allocated addresses and just try them all (
ssh linaro@192.168.x.y). If you are unlikely then you can use an nmap sweep to find the device (plug in, sweep, unplug, sweep and compare the difference to learn the IP address). - Use the debug UART to see the boot message. This is a powerful technique but needs extra hardware (the debug UART uses 1.8v signals so you have to get a special adapter) so trying #1 and #2 may be better.
Thanks I was able to access the system via ssh. I can investigate the display issue now.
@Caradhras I’m curious if you figured this out. I’m having the same issue with a new board. I can ssh in but no video when connected to my regular desktop display. I will try some other screens in the house.
Yes, my monitor was to recent for the board, so I turned on HDMI legacy mode and it worked.
@Caradhras Is that a setting in Debian or a setting on your monitor?
@danielt Do you have any ideas?
It does seem to depend on the monitor. My regular TVs would come up at 4k/30 but I found another monitor that would come up at 4k/60.
