1. uart_set_line_inverse API issue, https://github.com/espressif/esp-idf/issues/673 2. tx buffer length issue, https://github.com/espressif/esp-idf/issues/710
1. uart_set_line_inverse API issue, https://github.com/espressif/esp-idf/issues/673 2. tx buffer length issue, https://github.com/espressif/esp-idf/issues/710