Hi. Is it possible to connect a parallel LCD (HD44780 4*40) and 8 LED's to the same parallel port. / Fredrik
Depends on what exactly you want to do with the LEDs and the LCD. If you just want the LEDS to flash based on the signals that your sending to the LCD then yes you can. All you need then is hookup to 8-bit buffers (non-inverting) to the parallel port and then hook up the LEDs to the one and the LCD to the other. If you want to control the LEDs separatelly to the LCD then you can still do it, but you won't be able to control them at the same time. What you'll need is two bi-state latches and an inverter. You hook it up then in such a way that the one latch is on when the other isn't. You can then use the pin that is normally used to control the backlight to control the latches and your set. If anyone sees any mistakes please correct me
