Compatibility Issue


Is this LCD compatible with LCD Library for Arduino please? I noticed that for example the back light is switchable either permanently or by 4bit mode (through a command)

Thanks for your time

The display itself looks like it should be compatible.

The backlight is another story. Here is my interpretation of what they are doing.

A standard Hitachi HD44780U compatible LCD requires 14 pins when it is run in 8-bit mode. Displays with a backlight require at least one more pin although most have two.

What they are saying is that to use the backlight you must run the LCD in it's 4-bit mode (which is the most popular way). Then they have you rewire the board to power (and control) the backlight with one of the four pins that have been freed up.

There is no 'command' to control the backlight, you will have to come up with the code yourself but that is a trivial problem.


Strange indeed.

As you'll be soldering (at SMD parts) anyway if you want to control this unit and for some reason want to use 8 bits, that's got to be possible too.
You'd have to remove R5 and have a look at the solder pads of R6 and R7.
They are connected at one side.
Solder a wire to the other pad of R7 (so the one that is not connected to R6), and connect that to your backlight control (do not forget a current limiting resistor).

Ok I didn't read that part for some stupid reason but I still wanted to know if the 4bit interface of this LCD will work with LCD Library. The pinouts match thats for sure so I guess I can work with this.

I am trying to find a small LCD to fit in a small handheld box which is only 55mm wide (internally)

Thanks all :slight_smile:

The 4-bit interface - which is almost always the one that is used as it seems absurdly wasteful to allocate four more data lines for no good purpose (speed is hardly an issue) - certainly should work just fine as long as you identify the correct connections in the descriptor.

If you do the modification to bring the LED drive connection out to one of the terminals - which is much neater than a flying wire - the obvious thing to do is to carefully remove R5 and re-fit it into the R7 position, removing R6. You will need a transistor to control this as the LED is specified as 50 to 80 mA, much more than the Arduino can supply directly from a port pin.