Basic pocket computer display modification

WARNING! I DO NOT HAVE ANY HARDWARE TO TEST THIS WITH! THIS MAY STILL BE BROKEN!

tl;dr

Now that that's out of the way, here's a (potentially) fixed copy of the script:

https://gist.github.com/zanothis/9167288

I had to make the fixes using only the code and the algorithm contained therein. The lcdChar function had a few things mixed up.

The original used the following:

for (int xg = 0 ; xg < 16 ; xg++) {

screenMem[0 + xg] = screenMem[40 + xg];

screenMem[40 + xg] = screenMem[16 + xg];

screenMem[16 + xg] = screenMem[56 + xg];

screenMem[56 + xg] = 32;

}

This seems to be trying to handle the interlaced copy of the display lines. The problem is that 40 is valid for a 20x4 display, while the 16 would be useful for a 16x4 display, and the 56 is useful in neither.

If you need to, picture the 1-dimensional array as it will be displayed where the number values are the array indexes (16x4 used, though the same applies to 20x4):

0 ... 15

32 ... 47

16 ... 31

48 ... 63

The algorithm should be written as follows:

for (int xg = 0 ; xg < 16 ; xg++) {

screenMem[0 + xg] = screenMem[32 + xg];

screenMem[32 + xg] = screenMem[16 + xg];

screenMem[16 + xg] = screenMem[48 + xg];

screenMem[48 + xg] = 32;

}

Then screenMem only needs to have a size of 64.

There are also several places that call doFrame(56) that should actually be doFrame(64). Line 1471 is an exception and should be:

doFrame(48 + cursorX);

Once those changes are made, changing to any other size is as easy as changing all the 16s to 20s, the 32s to 40s, the 48s to 60s and 64s to 80s in the case of a 20x4 display.

I didn't realize there was so much interest in this!

My original code was quite the kludgy hack (which is common when you only have a few weeks)

BASICally, the interpreter is meant to output via serial. I followed the chain down to a single serial print char, and rewrote that part to instead fill that data to "screen memory"

The trick is once a Hitachi 44780 goes past 2 lines the lines aren't numbered sequentially (they are interlaced)

On top of this, for the display to coarse scroll, it needs to keep track of the data.

A more elegant solution would allow you to set constants of DIisplay Size, so it would know the width of lines.

Hello Ben i been following your videos for some time now and i must say you are doing a awesome job man. I know a lot of hard work  that i not  show in the videos. i just recently developing a pocket pc using arduino. and i looked at your coding and you did a awesome job thank you. i have a hard time coding or hardware of things or to even get started my self but watching your videos it help me a lot thank you.

Your project is great.

I am still working on it, but for some reason the LCD is still not working.

I already developed a driver (based on the work on Cliffleblog) for the Chatpad, but the LCD is just not working.

Here are some photos of the LCD and the project components.

The mega will later be replaced by a single ATmega328p and the blue LCD is going to be replaced by a green one (HD44780, 20x4 aswell).

I hope anybody, including Ben, whose show I really like and follow since years, can help me solving the LCD problem.

I am using the code from github that was posted earlier here in this thread.

Greetings, Muessigb

Hey i got the same fault on the LCD.

I also tried to use the newer version of Arduino TinyBasic (0.13) but it fails.

And i have another big problem. The Layout of my Chatpad is different than that from the example, this means the mapping of the keys dont match. I tried to remap this. This was not as easy as i think but i got it.

Old Map:

const char scanMap[50] = {      // i could output directly idx,

  8,  9, 10, 40, 20, 30, 47,    // but maybe a translation map

41, 42, 43, 39, 44, 38, 45,    // can prove useful in future.

31, 32, 33, 35, 34, 36, 37,    // starts from 1...think 0

21, 22, 23, 25, 24, 26, 27,    // should be reserved for

11, 12, 13, 15, 14, 16, 17,    // future use

  1,  2,  3,  5,  4,  6,  7,

28, 18, 19,  0,  0, 29, 46 };

const char serialMap[4][49] = { // CHARACTER MAPPING MATRIX for "pure serial mode"

// normal char press

{56,  57,  48,  13, 112,  44,   0,

  0,   0,   0,  46,  32, 109,   0,

  0, 121, 120, 118,  99,  98, 110,

97, 115, 100, 103, 102, 104, 106,

113, 119, 101, 116, 114, 122, 117,

49,  50,  51,  53,  52,  54,  55,

107, 105, 111,   0,   0, 108,   8},

// shifted

{56,  57,  48,  13,  80,  44,   0,

  0,   0,   0,  46,  32,  77,   0,

  0,  89,  88,  86,  67,  66,  78,

65,  83,  68,  71,  70,  72,  74,

81,  87,  69,  84,  82,  90,  85,

49,  50,  51,  53,  52,  54,  55,

75,  73,  79,   0,   0,  76,   8},

// green alt

{56,  57,  48,  13,  61,  39,   0,

  0,   0,   0,  63,  32,  58,   0,

  0,  60,  62,  45, 126,  42,  59,

  0,   0,   0,   0,   0, 123, 125,

33,  34, 128,  37,  36,  38,  47,

49,  50,  51,  53,  52,  54,  55,

91,  40,  41,   0,   0,  93,   8},

// red alt

{56,  57,  48,  13,  92,  35,   0,

  0,   0,   0,   0,  32,   0,   0,

  0,   0, 124,  95,   0,  43,   0,

  0,   0,   0,   0,   0,  96,   0,

64,   0,   0,   0,   0,  94,   0,

49,  50,  51,  53,  52,  54,  55,

  0,   0,   0,   0,   0,   0,   8}

};  ////////// END OF MAPPING MATRIX

I only Map the important Keys. Special Key are not important for this Projekt.

New Map:

const char scanMap[50] = { // i could output directly idx,

  8, 9, 10, 40, 20, 30, 47, // but maybe a translation map

41, 42, 43, 39, 44, 38, 45, // can prove useful in future.

31, 32, 33, 35, 34, 36, 37, // starts from 1...think 0

21, 22, 23, 25, 24, 26, 27, // should be reserved for

11, 12, 13, 15, 14, 16, 17, // future use

  1, 2, 3, 5, 4, 6, 7,

28, 18, 19, 0, 0, 29, 46 };

const char serialMap[4][49] = { // CHARACTER MAPPING MATRIX for "pure serial mode"

// normal char press

{56, 57, 48, 13, 112, 44, 0,

  0, 0, 0, 46, 32, 109, 0,

  0, 121, 120, 118, 99, 98, 110,

97, 115, 100, 103, 102, 104, 106,

113, 119, 101, 116, 114, 122, 117,

49, 50, 51, 53, 52, 54, 55,

107, 105, 111, 0, 0, 108, 8},

// shifted

{56, 57, 48, 13, 80, 44, 0,

  0, 0, 0, 46, 32, 77, 0,

  0, 89, 88, 86, 67, 66, 78,

65, 83, 68, 71, 70, 72, 74,

81, 87, 69, 84, 82, 90, 85,

49, 50, 51, 53, 52, 54, 55,

75, 73, 79, 0, 0, 76, 8},

// green alt

{56, 57, 48, 13, 61, 39, 0,

  0, 0, 0, 63, 32, 58, 0,

  0, 60, 62, 45, 126, 42, 59,

  0, 0, 0, 0, 0, 123, 125,

33, 34, 128, 37, 36, 38, 47,

49, 50, 51, 53, 52, 54, 55,

91, 40, 41, 0, 0, 93, 8},

// red alt

{56, 57, 48, 13, 92, 35, 0,

  0, 0, 0, 0, 32, 0, 0,

  0, 0, 124, 95, 0, 43, 0,

  0, 0, 0, 0, 0, 96, 0,

64, 0, 0, 0, 0, 94, 0,

49, 50, 51, 53, 52, 54, 55,

  0, 0, 0, 0, 0, 0, 8}

}; ////////// END OF MAPPING MATRIX

But i dont now how to Compile this sketch. There are many files but i dont now wich i have to use

It would be very nice if anyone can help me

Greets

Kaoala

PS: Sry for the bad english

Hey, if anybody have a Layout of the Chatpad like me:

he can use this .hex file (https://drive.google.com/file/d/0B5ekX3iu3Pl-RU9Kbm9FNzg3aUE/view?usp=sharing)

Because the Original Mapping does not fit. If you have any questions, you can write me

Greets Kaoala

I have that mapping. But because of the lack of an PIC Programmer and because my Bus Pirate wasn't able to do anything, I just wrote a driver based of one I found online.

So I wrote a PS2Keyboard like library for the Arduino. If anybody needs it, just ask. This library works with the original firmware.

I know it was like 4 years ago since anyone touched this thread but here is my 20x4 code: https://pastebin.com/Wxs2x79A

Also mine uses a custom button matrix and it basically uses every single pin on the nano .