How switch to IDF 4.1 in ADF 2.1 ?
According to https://github.com/espressif/esp-adf/releases/tag/v2.0 ESP-ADF 2.0 has been released with support for ESP-IDF 4.0 and 4.1
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(Added support for more IDF versions (v3.3.1, v4.0 and v4.1))
But It doesn't show how to do it.
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