Just wanted to share my struggle to upgrade a pixhawk yesterday, and wonder if anyone else has had similar experiences. I actually ended up upgrading no less than 3 devices: One white 2.4.8 clone, and two “Radiolink Pixhawk” (probably the exact same as a 2.4.8, although these have an issue with no detected internal compass). Two of these I had previously discarded as trash and put in a drawer, one was installed in a sealed boat and acted weird.
The process started struggling to upgrade the pixhawk in the boat. I have installed an external USB module for this purpose. And before anyone suggest you cannot use such a device to do the upgrade: Of course you can. I also did not bother to try a different USB cable, something usually advice as a solution to overcome problems when someone asks. I find the cable to rarely be the cause of firmware upgrade issues. This was also not the case yesterday.
After a series of unsuccessful attempts I decided to try out my previously discarded pixhawks. And to my surprise I got them both working and also successfully updated with the 4.2.3 Rover. But not before I: Popped out the MicroSD card. I also, willing to try anything as these devices were probably trash anyway, used the bootloader update and happily accepted the warnings.
With this experience I then cut open my sealed boat and built the pixhawk out of its waterproof enclosure. And: The bootloader would not update as long as the the MicroSD card was installed. Nor did it help to connect directly to the pixhawk micro USB port to do firmware upgrade. Out with the MicroSD card here as well. And then the bootloader update and the subsequent firmware upgrade went effortlessly.
To sum up, all my struggles were solved by removing that memory card. I for sure have no plan to push these back in. I may buy some new ones. Or I disregard it completely as I know exactly how to successfully configure the pixhawk and really have no need for those logs. To be decided.
Anyone else who have had similar experiences?