I'm trying to implement Asian symbols with my max7219 and using the 8x8 led displays.
I've had a look online and I've found libraries for the max7219 but it is only in ASCII. I was wondering if there was an easy way of implementing using a UNICODE library - assuming there is one.
I'd like to easily copy and paste say " な " this character into my code and print it onto the LED displays. So far, all attempts have not been working. My other option is to use binary/hex to manually draw up the symbols but I would really prefer to make it easy for the user to copy and paste any character and it prints onto the LEDs. Or will I have to create my own Arduino Library?
Any help is greatly appreciated!
Many thanks.
The problem with Unicode is that it's just so damn big (the first kana is U+3041), and most Arduinos have not nearly enough flash to store all the characters required.
My recommendation is to use an 8-bit encoding that maps to all the characters you need. I suggest starting with the character set used by the HD44780UA00 and replacing the characters where they make sense. Since some other libraries already use this set it won't be a huge leap to use them with your display.
You can't copy and paste a CHARACTER in a 8x8 matrix.
You have to find an 8x8 matrix of your font (katakana, kanji, etc.), and build an array that contains all the characters in a bit-by-bit format.
To all who have commented that MAX7219 is a 7-segment display, I want to say that MAX7219 is an IC which contains a buffer of 8x8 bit. You can use it to drive an 8x8 LED matrix, or an 8-in-line 7-segments (plus a decimal point) display, or anything else.
Related
If you type ps aux into your terminal and make the window really small, the output of the command will not wrap and the format is still very clear.
When I use printf and output my 5 or 6 strings, sometimes the length of my output exceeds that of the terminal window and the strings wrap to the next line which totally screws up the format. How can I write my program such that the output continues to the edge of the window but no further?
I've tried searching for an answer to this question but I'm having trouble narrowing it down and thus my search results never have anything to do with it so it seems.
Thanks!
There are functions that can let you know information about the terminal window, and some others that will allow you to manipulate it. Look up the "ncurses" or the "termcap" library.
A simple approach for solving your problem will be to get the terminal window size (specially the width), and then format your output accordingly.
There are two possible answers to fix your problem.
Turn off line wrapping in your terminal emulator(if it supports it).
Look into the Curses library. Applications like top or vim use the Curses library for screen formatting.
You can find, or at least guess, the width of the terminal using methods that other answers describe. That's only part of the problem however -- the tricky bit is formatting the output to fit the console. I don't believe there's any alternative to reading the text word by word, and moving the output to the next line when a word would overflow the width. You'll need to implement a method to detect where the white-space is, allowing for the fact that there could be multiple white spaces in a row. You'll need to decide how to handle line-breaking white-space, like CR/LF, if you have any. You'll need to decide whether you can break a word on punctuation (e.g, a hyphen). My approach is to use a simple finite-state machine, where the states are "At start of line", "in a word", "in whitespace", etc., and the characters (or, rather character classes) encountered are the events that change the state.
A particular complication when working in C is that there is little-to-no built-in support for multi-byte characters. That's fine for text which you are certain will only ever be in English, and use only the ASCII punctuation symbols, but with any kind of internationalization you need to be more careful. I've found that it's easiest to convert the text into some wide format, perhaps UTF-32, and then work with arrays of 32-bit integers to represent the characters. If your text is UTF-8, there are various tricks you can use to avoid having to do this conversion, but they are a bit ugly.
I have some code I could share, but I don't claim it is production quality, or even comprehensible. This simple-seeming problem is actually far more complicated than first impressions suggest. It's easy to do badly, but difficult to do well.
I have installed a Bramma TTF file in my windows 8 system. Through a windows character map, I was able to find individual character code. Attached below the screenshot of the map. We can see at the right bottom side, the character code for "!" is 0x21. Similarly, I can find all the character code of all other letters.
Now I defined a character mapping for this font with my US based keyboard layout. For example, I mapped physical character 'a' in the keyboard to the character shown in 3rd row and 1st column. [whenever I hit 'a' from the keyboard, the corresponding character has to be displayed]
I would like to write a background C program such that it listens the keyboard hit and as per my previously defined character mapping, my C program should output that mapped character. i.e., when i hit character 'a' from the keyboard it should return the mapped character.
Can any one help me out in solving this problem or else just give me a lead towards the solution.
I'm somewhat familiar with these kind of fonts, they popped up in other questions at SO. The kind of questions from users that tried to deal with the consequences of using such a font. They are rather grave.
The biggest problem is that this font is not Unicode compatible. The actual string that underlies the text that's rendered to the screen is very different, containing characters from the ANSI character set. What goes horribly wrong is when the program that displays these strings saves the data. The data file contains the original strings, a good example is an Excel spreadsheet. This spreadsheet just contains gibberish when it is read by any other program. Especially bad when read by a program on another machine that doesn't have the same font installed. Very, very painful.
You are in fact making this problem worse by even destroying the normal mapping between keyboard to ANSI character. The 1st character in the 3rd row is produced by typing a capital I (eye) on the keyboard.
The message is clear: don't do this. Windows supports Unicode compatible fonts with Indic scripts well, fonts like Sylfaen, Mangal, Latha. All of which are available on my Windows 8 machine, about ten thousand miles away from where they are normally used. It also has Indic keyboard layouts available under the Language applet, I just picked one as an example:
Well, it is your funeral. You don't have to write a C program to translate these keystrokes, you need a custom keyboard layout. It is a DLL. You normally need the DDK to build them, but there is simple tooling available to auto-generate them. It doesn't get any easier than with MKLC, the Microsoft Keyboard Layout Creator. Web page and download link are here.
Probably you should use autohotkey.
With this application, you can listen to a set of keys, & then send a different set of keys.
This can be used as implementation of "autocorrect"
e.g.
:*:btw::By the way `
will autocorrect btw to By the way.
autohotkey supports quite complicated scripts, & many scripts are already available online.
On another note, if you only want english keyboard to print malayalam unicode characters, you may also think of a popular software called baraha
Google's Virtual Keyboard (also works with your physical keyboard)
https://code.google.com/apis/ajax/playground/#virtual_keyboard
http://www.tavultesoft.com/ allows you to create keyboards for MSWindows and the web. Over 1000 keyboards are readily provided. There is a developer and a user version. With the developer version you may create installation programs which install fonts, keyboards, keymaps and documentation.
I am parsing text using C and am getting an output of 0019 boxes in the terminal. After some research I have found that these are END OF MEDIUM control characters:
"Intended as means of indicating on paper or magnetic tapes that the end of the usable portion of the tape had been reached." - Wikipedia
How do I look for them and not include them in the output? Such as an if statement looking for them. They do not have an actual character so Im not sure how I would go about actually looking for them. Is it possible to use their HEX value (0x0019) to find them?
EDIT: I am parsing through html so I see no reason for that character to be there..
You could use e.g. isprint or it sibling functions.
I am new to C; I have an image file translated by means of online tools into a .h and .c file. The C file contains an array of 1024 16 bit hexadecimal numbers, used to denote on/off of bits. I want to read this file and draw the image onscreen using DMA...but I'm very much at a loss as to how to do this. Can anybody out there help? Does anyone even know what I'm talking about?
To draw an image onscreen, use DMA[3]. This is channel 3 of DMA for images.
This is how you set up DMA in a .h file:
http://nocash.emubase.de/gbatek.htm#gbadmatransfers
And then to draw an image using DMA:
#######include image.h
DMA[3].src = (specify your image source here, where you're drawing from)
DMA[3].dst = (where you're drawing pixels to)
In your scenario, I think you indicate the name of the file in your source.
Keep in mind you're using POINTERS to images for src and dst.
DMA[3].cnt = (how many times you want to do it) | flag1 | flag2...
Here are some flags:
DMA_SOURCE_FIXED means you draw from the same pixel over and over again. If this is what you want, then turn this bit on in cnt.
DMA_DESTINATION_FIXED applies that you're drawing TO the same pixel over and over again. If this is what you want, then turn on this bit in cnt.
Otherwise, DMA_SOURCE_INCREMENT and DMA_DESTINATION_INCREMENT are on by default (if not, you can turn them on in cnt anyway).
This is what I used for VBA, so I'm sorry if this does not answer your question (I'm kind of inexperienced with C as well...).
#Michael Yes, I mean the Visual Boy Advance
I am writing a low level C app, and I'm planning on using an array to store my fonts.
The problem is, the font I'd like to use is in TrueType format. How shall I:
Convert TTF to a large sized, B&W, bitmap
font without any kind of AA (not strictly programming
related);
Parse the B&W bitmap font into a C byte array.
What format should I use for the bitmap? Should be simple enough that me, a beginner programmer with little over a year of experience can write a parser to store it in said array.
I don't want to use external libraries, and I'd like to keep C Std. Lib. usage to a minimum. It's for a college project and I want to write everything myself.
It's not the most professional or cleanest, but here's what I'd do in your situation:
Choose a monospaced font and a size where each character is an integral number of pixels.
Open GIMP (or your favorite image editing program) and make an image that's font_width pixels wide and font_height*96 pixels tall.
Make a text element anchored at the upper-left corner containing <space> <newline> ! <newline> " <newline> # <newline> ... (i.e. all the ASCII glyphs).
Save it as an uncompressed image format that's easy to process, like PNM.
Load it into an array of type uint8_t [96][font_height][font_width].
Use Win32 GDI APIs to write bitmaps: create a bitmap, print a letter, use GetPixel to read it. Serialize to .c file.
Try Freetype. It can provide you with data you can use for your bitmap creation.