I managed to somehow make it display the correct RPM. I have to follow these steps: -all slots for sensors are set to fuel level. Only rpm is displayed. Don’t know if it makes a difference, but did not try another way. -plug the dongle and start the engine; -DMD2 starts and in a few seconds connects to the dongle – the Bluetooth icon in DMD2 turns blue and a fixed value for rpm is shown, always the same value, something like 4xxx. The dongle lights green and the green lights twinkle, as it would communicate/exchange data. – with the engine running I quickly unplug the ODB dongle, the Bluetooth icon in DMD2 turns red, and then plug ODB dongle back in again. The Bluetooth icon in DMD2 turns blue for a few seconds, then red again, then blue, and stays blue. Now the rpm value is displayed properly and responds to the gas pedal. -if I exit DMD2 or restart the android device, I have to redo the whole procedure.
I have updated to version 2.82. I can see that the connection is slower. But the method described above does not work anymore. After connection, if I unplug then plug the dongle back, it takes a while to reconnect and then the same fixed values are displayed ( no more blue bluetooth icon for a few seconds, then red, then blue and data displayed properly).