Update README.md

README.md

@@ -155,6 +155,10 @@ And the super cool project https://github.com/rochuck/squeeze-amp-too
 ## Configuration
 To access NVS, in the webUI, go to credits and select "shows nvs editor". Go into the NVS editor tab to change NFS parameters. In syntax description below \<\> means a value while \[\] describe optional parameters. 
 
+As mentionned above, there are a few dedicated builds that are provided today: SqueezeAMP and Muse but if you build it yourself, you can also create a build for T-WATCH2020. The default build is a generic firmware named I2S which can be configured through NVS to produce *exactly* the same results than dedicated builds. The difference is that parameters must be entered and can accidently be erased. The GUI provides a great help to load "known config sets" as well. 
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+By design choice, there is no code that is only embedded for a given version, all code is always there. The philosophy is to minimize as much as possible platform-specific code and use of specific `#ifdef` is prohibited, no matter what. So if you want to add your own platfrom, please look **very hard** at the `main\KConfig.projbuild` to see how you can, using parameters below, make your device purely a configuration-based solution. When there is really no other option, look at `targets\<target>` to add your own code. I will not accept PR for code that can avoid creating such dedicated code whenever possible.
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 ### I2C
 The NVS parameter "i2c_config" set the i2c's gpio used for generic purpose (e.g. display). Leave it blank to disable I2C usage. Note that on SqueezeAMP, port must be 1. Default speed is 400000 but some display can do up to 800000 or more. Syntax is
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