** Found the solution in this thread : https://www.avrfreaks.net/forum/medbg-tool-not-appearing-attiny1616-project
I am trying to use a Xplained-Mini 817 board to program an ATtiny1614 located in a bareboard, using the UPDI channel. The Atmel Studio 7 did work as charm with the AtTiny817 present in the demo board, so I disconnected the 817 from UPDI line ( that comes from the MEGA32U4) in order to have only one device on it and connected it to the ATtiny1614.
I started a new project selecting the 1614 and it is correctly build. In order to program it in the device I went to the Device Programming window and there my little nightmare started. First, there is only one device I can select (ATtiny817). I found that can write the ATtiny1614 manually (and Apply button) and the window refreshes showing the correct ATTiny1614 device signature, target voltage, etc. I can even see the communicaton at the UPDI line with my scope.
So, the Studio 7 can see my device. But, when I close this window it forgets the device and does not program it. Goes only to simulation.
In the Project Properties, tool tab, there is no mEDBG option for the debugger/programmer.
Therefore, I came to you guys to know if there is a way to tell the Atmel Studio 7 that it shall keep the selected device.