Hi Panos,

I'm sure, if you use drivers as I described, the problem goes away.
If this to many expenditure for you, you can also try using stronger pull ups, e.g. 2.2kOhm on every control and data line against VCC.
But drivers are always the better solution.

Only if noise unimportant (e.g. driving relays, LEDs, reading keyboards), then the 8051 lines can be direct feed outside the gadget.


Peter