Hi guys,

For my graduation I developed my own board to sniff out PLC communication. Now I'm running into some problems and I was hoping you might be able to help me out/have some good tips.

As processor I chose a SoM: phycore AM335x (https://www.phytec.eu/product-eu/system-on-modules/phycore-am335x-download/).

From an SD card the SoM has to be booted but I run into problems that hamper

the progress and I can't get out. My SDIO circuit looks good and the SoM detects the SD card as well. I followed the steps for flashing the correct OS on the SD card as described by the supplier.

Through an RS232 interface I can read the SoM, so I also have some logging. In the attachment a screenshot of the logging is added. After 5 seconds the SoM seems to go into sleep mode and pretty little happens. In the datasheet of the AM335x I can partly trace what is happening (page 5029 of: https://www.ti.com/lit/ug/spruh73q/spruh73q.pdf?ts=1599120014623). It does not see any bootsources so when the watchdog time is up the process is stopped.

I didn't "wire out" the SYSBOOT pins of the processor (which might not be very handy afterwards) but the processor should be able to boot from the SD card.

Do you have any tips or ideas what the problem might be? Like to hear from you.

Kind regards,

Martijn

-- Sent from: http://u-boot.10912.n7.nabble.com/