Мне нужно уменьшить объем памяти, требуемый библиотекой KeDei TFT, используемой с Osoyoo 3,5 сенсорный TFT-дисплей шилд для Arduino Uno и ATmega 2560. Когда я пытаюсь написать простое приложение для Arduino, использующее TFT-дисплей с библиотекой KeDei, большая часть доступной памяти на Arduino занята самой библиотекой.
К сожалению, я обнаружил, что, хотя ATmega 2560 имеет необходимый объем памяти, библиотека KeDei TFT не обеспечивает правильных сенсорных координат, когда TFT-дисплей используется с этим устройством, поэтому ATmega 2560 невозможна, если не будет поддержки клиентов Osoyoo. решение.
Исследуя исходный код библиотеки, я нашел в файле KeDei_font.cpp таблицу растровых шрифтов, используемую для генерации отображаемых символов. Эта таблица растровых шрифтов представляет собой массив unsigned char font16_B[96][16]
и, по-видимому, занимает основное место в памяти. Этот массив содержит растровые шрифты для символов ASCII от пробела 0x20
до тильды 0x7e
.
Одна вещь, которую я сделал, это уменьшить количество символов, удалив строчные буквы и преобразовав строчные буквы в прописные. В результате получается таблица const unsigned char font16_B[59][16]
, размер которой чуть больше половины исходной таблицы.
При таком подходе я также исключаю несколько других знаков пунктуации, но пока я отображаю только буквенно-цифровые символы и пробелы, это будет работать.
#if defined(SMALLER_FONT_TABLE)
static const unsigned char font16_B[59][16] = {
#else
static const unsigned char font16_B[95][16] = {
#endif
{0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00},/*" ",0*/
{0x00,0x00,0x00,0x18,0x18,0x18,0x18,0x18,0x18,0x18,0x00,0x00,0x38,0x38,0x00,0x00},/*"!",1*/
{0x00,0xD8,0xFC,0x6C,0x36,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00},/*""",2*/
{0x00,0x00,0x00,0x6C,0x6C,0x6C,0xFF,0x36,0x36,0x36,0xFF,0x36,0x36,0x36,0x00,0x00},/*"#",3*/
{0x00,0x00,0x18,0x3C,0x7E,0x7E,0x1E,0x1C,0x38,0x78,0x78,0x7E,0x7E,0x3C,0x18,0x18},/*"$",4*/
{0x00,0x00,0x00,0x66,0x6F,0x3F,0x3F,0x3F,0x7E,0xF8,0xFC,0xFC,0xFC,0x66,0x00,0x00},/*"%",5*/
{0x00,0x00,0x00,0x1C,0x36,0x36,0x36,0x1E,0xFE,0x6F,0x7B,0x33,0xB3,0xFE,0x00,0x00},/*"&",6*/
{0x00,0x0E,0x0E,0x0C,0x07,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00},/*"'",7*/
{0x00,0xC0,0x60,0x30,0x30,0x18,0x18,0x18,0x18,0x18,0x18,0x30,0x30,0x60,0xC0,0x00},/*"(",8*/
{0x00,0x06,0x0C,0x18,0x18,0x30,0x30,0x30,0x30,0x30,0x30,0x18,0x18,0x0C,0x06,0x00},/*")",9*/
{0x00,0x00,0x00,0x00,0x18,0x18,0xFF,0x3C,0x3C,0xFF,0x18,0x18,0x00,0x00,0x00,0x00},/*"*",10*/
{0x00,0x00,0x00,0x00,0x18,0x18,0x18,0x18,0xFF,0x18,0x18,0x18,0x18,0x00,0x00,0x00},/*"+",11*/
{0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x0E,0x0E,0x0C,0x07},/*",",12*/
{0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0xFE,0x00,0x00,0x00,0x00,0x00,0x00,0x00},/*"-",13*/
{0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x0E,0x0E,0x00,0x00},/*".",14*/
{0x00,0x00,0x80,0xC0,0xC0,0x60,0x60,0x30,0x30,0x18,0x18,0x0C,0x0C,0x06,0x06,0x00},/*"/",15*/
{0x00,0x00,0x00,0x38,0x6C,0xC6,0xC6,0xC6,0xC6,0xC6,0xC6,0xC6,0x6C,0x38,0x00,0x00},/*"0",16*/
{0x00,0x00,0x00,0x18,0x1E,0x18,0x18,0x18,0x18,0x18,0x18,0x18,0x18,0x7E,0x00,0x00},/*"1",17*/
{0x00,0x00,0x00,0x7C,0xC6,0xC6,0xC6,0x60,0x60,0x30,0x18,0x0C,0xC6,0xFE,0x00,0x00},/*"2",18*/
{0x00,0x00,0x00,0x7C,0xC6,0xC6,0x60,0x38,0x60,0xC0,0xC0,0xC6,0x66,0x3C,0x00,0x00},/*"3",19*/
{0x00,0x00,0x00,0x60,0x70,0x78,0x6C,0x6C,0x66,0x66,0xFE,0x60,0x60,0xF8,0x00,0x00},/*"4",20*/
{0x00,0x00,0x00,0xFE,0x06,0x06,0x06,0x3E,0x6E,0xC0,0xC0,0xC6,0x66,0x3C,0x00,0x00},/*"5",21*/
{0x00,0x00,0x00,0x78,0x6C,0x06,0x06,0x3E,0x6E,0xC6,0xC6,0xC6,0x6C,0x38,0x00,0x00},/*"6",22*/
{0x00,0x00,0x00,0xFE,0x66,0x66,0x30,0x30,0x18,0x18,0x18,0x18,0x18,0x18,0x00,0x00},/*"7",23*/
{0x00,0x00,0x00,0x7C,0xC6,0xC6,0xC6,0x6C,0x38,0x6C,0xC6,0xC6,0xC6,0x7C,0x00,0x00},/*"8",24*/
{0x00,0x00,0x00,0x38,0x6C,0xC6,0xC6,0xC6,0xEC,0xF8,0xC0,0xC0,0x6C,0x3C,0x00,0x00},/*"9",25*/
{0x00,0x00,0x00,0x00,0x00,0x00,0x38,0x38,0x00,0x00,0x00,0x00,0x38,0x38,0x00,0x00},/*":",26*/
{0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x18,0x00,0x00,0x00,0x00,0x00,0x18,0x18,0x0C},/*";",27*/
{0x00,0x00,0x00,0xC0,0x60,0x30,0x18,0x0C,0x06,0x0C,0x18,0x30,0x60,0xC0,0x00,0x00},/*"<",28*/
{0x00,0x00,0x00,0x00,0x00,0x00,0xFF,0x00,0x00,0x00,0xFF,0x00,0x00,0x00,0x00,0x00},/*"=",29*/
{0x00,0x00,0x00,0x06,0x0C,0x18,0x30,0x60,0xC0,0x60,0x30,0x18,0x0C,0x06,0x00,0x00},/*">",30*/
{0x00,0x00,0x00,0x7C,0xC6,0xC6,0xCE,0xC0,0x60,0x30,0x30,0x00,0x38,0x38,0x00,0x00},/*"?",31*/
{0x00,0x00,0x00,0x3C,0x66,0xFE,0xFF,0xFF,0xFF,0xFF,0x7F,0xC6,0x66,0x3C,0x00,0x00},/*"@",32*/
{0x00,0x00,0x00,0x18,0x18,0x38,0x3C,0x3C,0x6C,0x7C,0x66,0xC6,0xC6,0xEF,0x00,0x00},/*"A",33*/
{0x00,0x00,0x00,0x3F,0x66,0x66,0x66,0x3E,0x66,0xC6,0xC6,0xC6,0x66,0x3F,0x00,0x00},/*"B",34*/
{0x00,0x00,0x00,0xFC,0xC6,0xC6,0x03,0x03,0x03,0x03,0x03,0xC6,0x66,0x3C,0x00,0x00},/*"C",35*/
{0x00,0x00,0x00,0x3F,0x66,0xC6,0xC6,0xC6,0xC6,0xC6,0xC6,0xC6,0x66,0x3F,0x00,0x00},/*"D",36*/
{0x00,0x00,0x00,0x7F,0xC6,0x36,0x36,0x3E,0x36,0x36,0x06,0xC6,0xC6,0x7F,0x00,0x00},/*"E",37*/
{0x00,0x00,0x00,0x7F,0xC6,0x36,0x36,0x3E,0x36,0x36,0x06,0x06,0x06,0x0F,0x00,0x00},/*"F",38*/
{0x00,0x00,0x00,0x7C,0x66,0x66,0x03,0x03,0x03,0xF3,0x63,0x66,0x66,0x3C,0x00,0x00},/*"G",39*/
{0x00,0x00,0x00,0xEF,0xC6,0xC6,0xC6,0xC6,0xFE,0xC6,0xC6,0xC6,0xC6,0xEF,0x00,0x00},/*"H",40*/
{0x00,0x00,0x00,0x7E,0x18,0x18,0x18,0x18,0x18,0x18,0x18,0x18,0x18,0x7E,0x00,0x00},/*"I",41*/
{0x00,0x00,0x00,0xFC,0x30,0x30,0x30,0x30,0x30,0x30,0x30,0x30,0x30,0x30,0x33,0x1F},/*"J",42*/
{0x00,0x00,0x00,0xFF,0x66,0x36,0x1E,0x1E,0x1E,0x36,0x36,0x66,0x66,0xFF,0x00,0x00},/*"K",43*/
{0x00,0x00,0x00,0x0F,0x06,0x06,0x06,0x06,0x06,0x06,0x06,0x06,0xC6,0xFF,0x00,0x00},/*"L",44*/
{0x00,0x00,0x00,0xFF,0x7E,0x7E,0x7E,0x7E,0x7E,0x7E,0x7E,0x7E,0x7E,0xFF,0x00,0x00},/*"M",45*/
{0x00,0x00,0x00,0xE7,0xCE,0xCE,0xDE,0xDE,0xF6,0xF6,0xF6,0xE6,0xE6,0xCF,0x00,0x00},/*"N",46*/
{0x00,0x00,0x00,0x3C,0x66,0xC3,0xC3,0xC3,0xC3,0xC3,0xC3,0xC3,0x66,0x3C,0x00,0x00},/*"O",47*/
{0x00,0x00,0x00,0x7F,0xC6,0xC6,0xC6,0xC6,0x7E,0x06,0x06,0x06,0x06,0x0F,0x00,0x00},/*"P",48*/
{0x00,0x00,0x00,0x3C,0x66,0xC3,0xC3,0xC3,0xC3,0xC3,0xDF,0xF7,0x76,0x3C,0xE0,0x00},/*"Q",49*/
{0x00,0x00,0x00,0x7F,0xC6,0xC6,0xC6,0x7E,0x36,0x36,0x66,0x66,0xC6,0xCF,0x00,0x00},/*"R",50*/
{0x00,0x00,0x00,0xFC,0xC6,0xC6,0x06,0x0C,0x38,0x60,0xC0,0xC6,0xC6,0x7E,0x00,0x00},/*"S",51*/
{0x00,0x00,0x00,0xFF,0xDB,0x18,0x18,0x18,0x18,0x18,0x18,0x18,0x18,0x3C,0x00,0x00},/*"T",52*/
{0x00,0x00,0x00,0xEF,0xC6,0xC6,0xC6,0xC6,0xC6,0xC6,0xC6,0xC6,0xC6,0x7C,0x00,0x00},/*"U",53*/
{0x00,0x00,0x00,0xEF,0xC6,0xC6,0x66,0x6C,0x6C,0x3C,0x3C,0x38,0x18,0x18,0x00,0x00},/*"V",54*/
{0x00,0x00,0x00,0xFF,0xDB,0xDB,0xDB,0xDB,0xFF,0xFF,0x7E,0x66,0x66,0x66,0x00,0x00},/*"W",55*/
{0x00,0x00,0x00,0xEF,0xC6,0x6C,0x6C,0x38,0x38,0x38,0x6C,0x6C,0xC6,0xEF,0x00,0x00},/*"X",56*/
{0x00,0x00,0x00,0xFF,0x66,0x66,0x3C,0x3C,0x18,0x18,0x18,0x18,0x18,0x3C,0x00,0x00},/*"Y",57*/
{0x00,0x00,0x00,0xFE,0x63,0x60,0x30,0x30,0x18,0x0C,0x0C,0xC6,0xC6,0x7F,0x00,0x00},/*"Z",58*/
#if !defined(SMALLER_FONT_TABLE)
// In the interest of reducing the memory requirements for the TFT library, we
// allow for the use of a smaller font table which eliminates the lower case letters
// as well as a few symbols. See below conversion of lower case letters to upper case.
// Richard Chambers, 04-25-2021
{0x00,0xF8,0x18,0x18,0x18,0x18,0x18,0x18,0x18,0x18,0x18,0x18,0x18,0x18,0xF8,0x00},/*"[",59*/
{0x00,0x00,0x06,0x06,0x0C,0x0C,0x18,0x18,0x18,0x30,0x30,0x60,0x60,0x60,0xC0,0xC0},/*"\",60*/
{0x00,0x3E,0x30,0x30,0x30,0x30,0x30,0x30,0x30,0x30,0x30,0x30,0x30,0x30,0x3E,0x00},/*"]",61*/
{0x00,0x78,0xCC,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00},/*"^",62*/
{0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0xFF},/*"_",63*/
{0x00,0x0E,0x18,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00},/*"`",64*/
{0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x7C,0xC6,0xF8,0xCC,0xC6,0xC6,0xFC,0x00,0x00},/*"a",65*/
{0x00,0x00,0x00,0x07,0x06,0x06,0x06,0x3E,0x6E,0xC6,0xC6,0xC6,0x6E,0x3E,0x00,0x00},/*"b",66*/
{0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x78,0xCC,0x06,0x06,0x06,0xCC,0x78,0x00,0x00},/*"c",67*/
{0x00,0x00,0x00,0xE0,0xC0,0xC0,0xC0,0xF8,0xCC,0xC6,0xC6,0xC6,0xEC,0xF8,0x00,0x00},/*"d",68*/
{0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x7C,0xC6,0xFE,0x06,0x06,0xC6,0x7C,0x00,0x00},/*"e",69*/
{0x00,0x00,0x00,0xF0,0x98,0x18,0x18,0xFE,0x18,0x18,0x18,0x18,0x18,0x7E,0x00,0x00},/*"f",70*/
{0x00,0x00,0x00,0x00,0x00,0x00,0x00,0xFC,0x66,0x66,0x3C,0x06,0x7C,0xC6,0xC6,0x7C},/*"g",71*/
{0x00,0x00,0x00,0x07,0x06,0x06,0x06,0x7E,0xCE,0xC6,0xC6,0xC6,0xC6,0xEF,0x00,0x00},/*"h",72*/
{0x00,0x00,0x00,0x1C,0x1C,0x00,0x00,0x1E,0x18,0x18,0x18,0x18,0x18,0x7E,0x00,0x00},/*"i",73*/
{0x00,0x00,0x00,0x70,0x70,0x00,0x00,0x78,0x60,0x60,0x60,0x60,0x60,0x60,0x66,0x3E},/*"j",74*/
{0x00,0x00,0x00,0x07,0x06,0x06,0x06,0xF6,0x36,0x1E,0x3E,0x36,0x66,0xFF,0x00,0x00},/*"k",75*/
{0x00,0x00,0x00,0x1E,0x18,0x18,0x18,0x18,0x18,0x18,0x18,0x18,0x18,0x7E,0x00,0x00},/*"l",76*/
{0x00,0x00,0x00,0x00,0x00,0x00,0x00,0xFF,0xB6,0xB6,0xB6,0xB6,0xB6,0xFF,0x00,0x00},/*"m",77*/
{0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x7F,0xCE,0xC6,0xC6,0xC6,0xC6,0xEF,0x00,0x00},/*"n",78*/
{0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x7C,0xC6,0xC6,0xC6,0xC6,0xC6,0x7C,0x00,0x00},/*"o",79*/
{0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x3F,0x6E,0xC6,0xC6,0xC6,0x66,0x3E,0x06,0x0F},/*"p",80*/
{0x00,0x00,0x00,0x00,0x00,0x00,0x00,0xF8,0xCC,0xC6,0xC6,0xC6,0xCC,0xF8,0xC0,0xE0},/*"q",81*/
{0x00,0x00,0x00,0x00,0x00,0x00,0x00,0xFF,0xDC,0x0C,0x0C,0x0C,0x0C,0x3F,0x00,0x00},/*"r",82*/
{0x00,0x00,0x00,0x00,0x00,0x00,0x00,0xFC,0xC6,0x06,0x7C,0xC0,0xC6,0x7E,0x00,0x00},/*"s",83*/
{0x00,0x00,0x00,0x00,0x00,0x18,0x18,0x7E,0x18,0x18,0x18,0x18,0x18,0x70,0x00,0x00},/*"t",84*/
{0x00,0x00,0x00,0x00,0x00,0x00,0x00,0xE7,0xC6,0xC6,0xC6,0xC6,0xE6,0xFC,0x00,0x00},/*"u",85*/
{0x00,0x00,0x00,0x00,0x00,0x00,0x00,0xEF,0xC6,0x6C,0x6C,0x3C,0x18,0x18,0x00,0x00},/*"v",86*/
{0x00,0x00,0x00,0x00,0x00,0x00,0x00,0xFF,0xDB,0xDB,0xFF,0xFF,0x66,0x66,0x00,0x00},/*"w",87*/
{0x00,0x00,0x00,0x00,0x00,0x00,0x00,0xFE,0x6C,0x38,0x38,0x38,0x6C,0xFE,0x00,0x00},/*"x",88*/
{0x00,0x00,0x00,0x00,0x00,0x00,0x00,0xEF,0xC6,0x6C,0x6C,0x3C,0x38,0x18,0x18,0x0F},/*"y",89*/
{0x00,0x00,0x00,0x00,0x00,0x00,0x00,0xFE,0x66,0x30,0x18,0x18,0xCC,0xFE,0x00,0x00},/*"z",90*/
{0x00,0xC0,0x60,0x60,0x60,0x60,0x60,0x30,0x60,0x60,0x60,0x60,0x60,0x60,0xC0,0x00},/*"{",91*/
{0x30,0x30,0x30,0x30,0x30,0x30,0x30,0x30,0x30,0x30,0x30,0x30,0x30,0x30,0x30,0x30},/*"|",92*/
{0x00,0x0E,0x18,0x18,0x18,0x18,0x18,0x30,0x18,0x18,0x18,0x18,0x18,0x18,0x0E,0x00},/*"}",93*/
{0x1C,0x76,0xC6,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00},/*"~",94*/
#endif
};
Затем в функции, которая генерирует символы и отображает их попиксельно, у меня есть следующий фрагмент кода, который преобразует символы нижнего регистра в символы верхнего регистра, если у меня включена меньшая таблица.
#if defined(SMALLER_FONT_TABLE)
// Lets translate the character to one of the printable
// characters in our font table. What we are doing is
// to translate lower case letters to upper case letters
// since in order to have a smaller font table taking up
// less memory we remove the lower case letters.
// Richard Chambers, 04-25-2021
if (_data < ' ' || _data > 'z') return;
if (_data >= 'a') _data = _data - 'a' + 'A';
#endif
char_i=(int)_data - ' ';
При таком подходе, когда я компилирую свой скетч Arduino с определенным SMALLER_FONT_TABLE, компиляция завершается со следующим предупреждением:
Sketch uses 12844 bytes (39%) of program storage space. Maximum is 32256 bytes.
Global variables use 1556 bytes (75%) of dynamic memory, leaving 492 bytes for local variables. Maximum is 2048 bytes.
Low memory available, stability problems may occur.
Что я могу сделать, чтобы еще больше уменьшить объем памяти, необходимой для отображаемого шрифта? Есть ли другой тип растрового шрифта, который использует меньше памяти?