SPOILER ALERT: The Red Pitaya powers down if the USB-micro connection on the module is used.
On of my troubleshooting attributes that can be either a blessing or a curse depending on the horse, is that I am persistent. In a previous post I used the term beating a dead horse. I did not like the outcome (failed) when I attempted to load the operating system on the QSPI & eMCC module. I figured, I would take up the switch and beat that horse some more.
I was set to look at SDR. That changed after reading a post. I had made a post on the Red Pitaya forum regarding some the issues I have faced, looking for some guidance. The replies left me thinking the problem was between the keyboard and chair.
A cruel step mother convinces their weak father to abandon Hansel and Gretel in the forest during a famine. Hansel uses white pebbles and later breadcrumbs to mark their path back home.
My breadcrumbs for this Red Pitaya fairy tale are the links to two vendor documents. The forum post suggested that Red Pitaya documentation is regularly updated every 30 days. I wanted to stay on the right path so vendor documents it is. The first link describes the full process. The second link deals with how to stop the watchdog timer.
Stopping the board during the U-boot autoboot countdown will cause the QSPI eMMC module to reboot Red Pitaya. At this point in the boot sequence, the Zynq processor has not yet started the Red Pitaya OS, so the watchdog kick signal on the E3 connector is absent. The E3 module firmware treats a missing watchdog signal as a system failure and triggers a power reset. The watchdog must be disabled before attempting to stop autoboot and enter the U-boot console.
My plan is to use USB-A to USB-micro cable for DFU programming details for this are found in the document.
Here is a summary of the steps:
STEP 1. Prepare an SD card with Red Pitaya OS 2.00 or later. Using version 3.00-57
STEP 2.Establish serial console access to Red Pitaya
STEP 3.Disable watchdog timer.
STEP 4.Boot the board, stop at U-boot autoboot.
STEP 5.From console run ums 0 mmc 0.
STEP 6.Flash the OS image to the eMMC from the PC.
STEP 7.Reboot into the full OS from the SD card.
STEP 8. Write boot.bin to QSPI flash with flashcp /opt/redpitaya/boot.bin /dev/mtd0.
STEP 9. Power off, remove the SD card, enable eMMC boot, and power on.
The procedure failed at STEP 3. When I plugged a USB-A from the Linux computer to USB-micro on the Red Pitaya the device immediately powered down.
In order to restore power to the Red Pitaya, I had to remove the USB-micro cable and remove the power cord to the Red Pitaya. A second attempted at using the USB-micros gave the same results. A different cable, a different combination of plugging cables in and trying it with no cables attached except for the USB-C power all ended with the power turning off on the Red Pitaya. Unless power and micro cable are removed, the board would not reboot.
The horse, that I refer to as loading the OS on the QSPI & eMCC module and not booting from the SD card, is down. I am unable to get it up, on the device I have.
I would ask the other RoadTest members to try plugging a USB-micro to USB-A cable into the module and see if they get the same results. There is nothing special you need to do other than plug the cable in between two devices. If other do not have a problem then the issue is with my board.
I'm moving on to examining SDR.
