ESP core installation

Development Tools IDE 1.x
1

I had a sketch (nearly) working on my Adafruit Huzzah module; found a (known) issue with wifi reconnect so tried to change the esp8266 core (v 2.4.0) to an earlier version (using Boards Manager in the Arduino IDE).
But now my sketch won't compile at all: "Board huzzah (platform esp8266, package esp8266) is unknown". Tried changing back to core version 2.4.0 but same problem.

What have I done wrong?

C:\Program Files (x86)\Arduino\arduino-builder -dump-prefs -logger=machine -hardware C:\Program Files (x86)\Arduino\hardware -hardware C:\Users\chris\AppData\Local\Arduino15\packages -tools C:\Program Files (x86)\Arduino\tools-builder -tools C:\Program Files (x86)\Arduino\hardware\tools\avr -tools C:\Users\chris\AppData\Local\Arduino15\packages -built-in-libraries C:\Program Files (x86)\Arduino\libraries -libraries C:\Users\chris\Documents\Arduino\libraries -fqbn=esp8266:esp8266:huzzah:CpuFrequency=80,FlashSize=4M3M,LwIPVariant=v2mss536,Debug=Disabled,DebugLevel=None____,UploadSpeed=115200 -ide-version=10801 -build-path C:\Users\chris\AppData\Local\Temp\arduino_build_651299 -warnings=default -prefs=build.warn_data_percentage=75 -prefs=runtime.tools.mkspiffs.path=C:\Users\chris\AppData\Local\Arduino15\packages\esp8266\tools\mkspiffs\0.2.0 -prefs=runtime.tools.xtensa-lx106-elf-gcc.path=C:\Users\chris\AppData\Local\Arduino15\packages\esp8266\tools\xtensa-lx106-elf-gcc\1.20.0-26-gb404fb9-2 -prefs=runtime.tools.esptool.path=C:\Users\chris\AppData\Local\Arduino15\packages\esp8266\tools\esptool\0.4.12 -verbose C:\Users\chris\Documents\Arduino\esp-logger\esp-logger.ino

Board huzzah (platform esp8266, package esp8266) is unknown

Error compiling for board Adafruit HUZZAH ESP8266.
2

The "Board ... is unknown" error occurs when a Boards Manager installation of a different version of a hardware package fails to completely uninstall the previous version. Here's how you solve it:

  • Navigate to the C:\Users\chris\AppData\Local\Arduino15\packages\esp8266\hardware\esp8266 folder.
  • You will see two folders. One is named by the version of the package you currently have installed, the other is named by the version of the package you previously had installed. Delete the folder with the previous version name. Please be very careful when deleting things on your computer. When in doubt back up!
3

Many thanks, that did the trick.