Unfortunately I bricked my NodeMCU. I load an init.lua script with an busy waiting script. It sends an http requests and then waits for one second with tmr.delay(...). Now I don't know how I could unbrick it.
I tried to flash the firmware (1.5.4) again but this didn't overwrite the init.lua file. I used esptool and the windows nodemcu-flasher. Both without success. I also tried to load a firmware without the necessary modules so that the init.lua should throw an error. But this also didn't work.
I would very happy if anyone had an idea.