Thanks a lot, I was almost there! I tried the UIflow firmware. The configuration button gave me an error. The burn asked me to connect to wifi. I asumed that it was the wifi of the m5, but thought that it would not work because the core was without OS. After your suggestion I unboxed the Core again (it was ready to send it back ;-) And now up and running again. Many thx ;-) Hopefully after the update the env II sensor wil work now. Because there the troubles started. Out of the box it did not work. Now i will retry.

I am a newby and wanted to upgrade the firmware of my m5stack fire. I downloaded the burner tool on osx, there i was connected to the usb port and did not see any buttons to upgrade the firmware. Then i accidently hit the erase button. And than , the bootloader was erased. Any idea to get it up and running with the Original stock software again? Or did i bricked it? In Windows i connected after this accident and showed the serial terminal showing
flash read error 1000, and rst: 0x10, boot 0x17 ets_main .c 317