MIDIbox Forum: MIDIbox Forum -> Connecting a CORE_STM32 to a Jaycar QP5518 Character LCD

Jaycar is an electronic component retailer in Australia.
They have stores in many locations and for this reason are a convenient source of parts.
The QP5518 (Jaycar's cat. number) is 2x16 yel/grn LED backlit display.
It is pin compatible with the Core32 EXCEPT VDD AND VSS NEED TO BE SWAPPED.
Why this is the case I have no idea, but it's sure to bring some to grief.
FIX: Simply peal back wires 1,2 of the ribbon used and twist it before crimping the IDC connector at one end. Thats Brown and Red in the picture below:



Additionally it is not necessary to connect pins 15,16 from J15 (backlight LED drive pins) as this display has the backlight LED wired with series resistors to Vss and Vdd. The default brightness is quite good, I found. It is possible to remove the LED connections to Vss,Vdd on the LCD PCB and use the variable brightness LED driver of the Core32 J15 pins 15,16 instead.