Character Display Module Explanations

Hi guys,

I’m starting to work with 16x2 CharDisplay.
There are 2 methods for print text on display:


In particular is interesting the method “Putc” because allows to print an ASCII character passing its decimal code.
This is the question: is supported Extended ASCII Table or not?

I tried to print the degrees char (°) but I can’t see it (the example above shows my attempt because 176 represents the extended ASCII table degrees char value). The display shows a minus char (-).

I haven’t looked at the code of the driver, or used it, but I would expect that you need to worry about the code that corresponds to the character, not the standard ASCII code… see something like as an example of the standard character set. Edit: I see 176 is also the degrees symbol - time to dig into the driver code :slight_smile:

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the display uses a display chip which is identified in the developers guide. find the data sheet for the chip. it should answer your question.

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Thanks for both replies, they’re useful! ;D

Another question: is it possible to paint custom characters using the standard driver?
(I worked with a similar char display programming in C++ and I could paint custom characters by setting dots on and dots off manually) .

If I remember the specs correctly you can define/design your own char set, but setting individual pixels is not possible.

@ Reinhard Ostermeier - Thanks for reply. It is exactly what I wanted to mean: a custom charset.

How can I define my own charset? Can you give me a tip?

You should look for the data sheet / docs of the Controller chip. Haven’t done this my self.

lots more if you use a search engine, look for “hd47780 datasheet”

The controller also allows for 8 custom symbols/chars. I have a modified driver here someplace that I wrote to allow for setting and using the custom chars. I’ll clean it up and post it later on :slight_smile:

Thanks to all for replies.

@ Brett - I found this link that lists all characters that HD44780 accepts (personally tested):

@ danibjor - That’s great! I’m courious to see your code! :slight_smile:

@ BigFoot - Here you go!

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@ danibjor - great, excellent! Thank you very much!!