前几天出去了，所以没有更新，今天是一个比较大的方面，就是液晶的显示，液晶显示器的应用为单片机带来了活力，平时我们写单片机，无法得到任何可视的现象，如IO的电平变化等，最简单的人机交互可以说是led灯和数码管灯，但其实说白了，液晶也是数据的传输，只不过是控制了比较小的灯并且以一个极快的速度更新以至于我们以为它并没有变化，由于液晶屏的种类，尺寸繁多，所以本次只讲原理，不再讲具体的液晶，笔者使用过数码管，lcd1602，oled12864和FSMC液晶（240*320），还有一种极力推荐的液晶--uart hmi液晶，淘宝上面有，有触摸版本的，因为有上位机，对于图片加载和使用都十分简单，可以说是功能强大但使用简单的一块液晶(其实我感觉就是液晶厂商自制了库文件，配合上位机，删除了人与数据的交流)，也可以通过串口与单片机连接，所以推荐。好的，现在我们开始说一下显示的问题：
大部分的液晶都是如下代码格式：（只是例子）
LCD_Init();
LCD_Clear(0, 0, 240, 320, BACKGROUND);
LCD_DispChar(60, 60, 'A', RED);
LCD_DispStr(10, 10, (uint8_t *)"This is a lcd demo to display ascii", RED);
LCD_DispStr(40, 100, (uint8_t *)"count:", RED);
LCD_DispStr(10, 250, (uint8_t *)"XiDian university", CYAN);
for( n=0; n<500000; n++ )
{
LCD_DisNum(100, 100, n, RED);
Lcd_Delay(0xAFFf>>4);
}
无非清屏，显示字符，数字，字符串，前面的两个数字代表位置，后面代表颜色，然后就要问到，这些函数背后都是什么！
我可以告诉你，这些函数大都由液晶厂商提供，但代码原理并不难，有兴趣的同学可以查看，我们也称为驱动文件，我们将厂商提供的文件导入工程中，就可以调用函数了，十分的方便。那就有人要问了，能不能显示任意形状呢？答案是可以的，液晶简单来说是由许多的小灯组成，我们称之为像素，我们通过点亮特定点来组成文字或形状，那么如何确定点亮哪些灯呢？不用单心，我们有字符制作软件，只要将需要的字符或者汉字导入，便会生出相应的码表，导入工程即可调用，也是十分的方便
一般工厂提供文件都是自带各种字符的像素表的，以一下代码为例（12*6），由于汉字过多，所以一般只导入使用的汉字
const unsigned char asc2_1206[95][12]={
{0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00},/*" ",0*/
{0x00,0x00,0x04,0x04,0x04,0x04,0x04,0x04,0x00,0x04,0x00,0x00},/*"!",1*/
{0x00,0x14,0x0A,0x0A,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00},/*""",2*/
{0x00,0x00,0x14,0x14,0x3F,0x14,0x0A,0x3F,0x0A,0x0A,0x00,0x00},/*"#",3*/
{0x00,0x04,0x1E,0x15,0x05,0x06,0x0C,0x14,0x15,0x0F,0x04,0x00},/*"$",4*/
{0x00,0x00,0x12,0x15,0x0D,0x0A,0x14,0x2C,0x2A,0x12,0x00,0x00},/*"%",5*/
{0x00,0x00,0x04,0x0A,0x0A,0x1E,0x15,0x15,0x09,0x36,0x00,0x00},/*"&",6*/
{0x00,0x02,0x02,0x01,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00},/*"'",7*/
{0x00,0x20,0x10,0x08,0x08,0x08,0x08,0x08,0x08,0x10,0x20,0x00},/*"(",8*/
{0x00,0x02,0x04,0x08,0x08,0x08,0x08,0x08,0x08,0x04,0x02,0x00},/*")",9*/
{0x00,0x00,0x00,0x04,0x15,0x0E,0x0E,0x15,0x04,0x00,0x00,0x00},/*"*",10*/
{0x00,0x00,0x04,0x04,0x04,0x1F,0x04,0x04,0x04,0x00,0x00,0x00},/*"+",11*/
{0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x02,0x02,0x01},/*",",12*/
{0x00,0x00,0x00,0x00,0x00,0x1F,0x00,0x00,0x00,0x00,0x00,0x00},/*"-",13*/
{0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x02,0x00,0x00},/*".",14*/
{0x00,0x10,0x08,0x08,0x08,0x04,0x04,0x02,0x02,0x02,0x01,0x00},/*"/",15*/
{0x00,0x00,0x0E,0x11,0x11,0x11,0x11,0x11,0x11,0x0E,0x00,0x00},/*"0",16*/
{0x00,0x00,0x04,0x06,0x04,0x04,0x04,0x04,0x04,0x0E,0x00,0x00},/*"1",17*/
{0x00,0x00,0x0E,0x11,0x11,0x08,0x04,0x02,0x01,0x1F,0x00,0x00},/*"2",18*/
{0x00,0x00,0x0E,0x11,0x10,0x0C,0x10,0x10,0x11,0x0E,0x00,0x00},/*"3",19*/
{0x00,0x00,0x08,0x0C,0x0A,0x0A,0x09,0x1E,0x08,0x18,0x00,0x00},/*"4",20*/
{0x00,0x00,0x1F,0x01,0x01,0x0F,0x10,0x10,0x11,0x0E,0x00,0x00},/*"5",21*/
{0x00,0x00,0x0E,0x09,0x01,0x0F,0x11,0x11,0x11,0x0E,0x00,0x00},/*"6",22*/
{0x00,0x00,0x1F,0x09,0x08,0x04,0x04,0x04,0x04,0x04,0x00,0x00},/*"7",23*/
{0x00,0x00,0x0E,0x11,0x11,0x0E,0x11,0x11,0x11,0x0E,0x00,0x00},/*"8",24*/
{0x00,0x00,0x0E,0x11,0x11,0x11,0x1E,0x10,0x12,0x0E,0x00,0x00},/*"9",25*/
{0x00,0x00,0x00,0x00,0x04,0x00,0x00,0x00,0x00,0x04,0x00,0x00},/*":",26*/
{0x00,0x00,0x00,0x00,0x00,0x04,0x00,0x00,0x00,0x04,0x04,0x00},/*";",27*/
{0x00,0x20,0x10,0x08,0x04,0x02,0x04,0x08,0x10,0x20,0x00,0x00},/*"<",28*/
{0x00,0x00,0x00,0x00,0x1F,0x00,0x00,0x1F,0x00,0x00,0x00,0x00},/*"=",29*/
{0x00,0x02,0x04,0x08,0x10,0x20,0x10,0x08,0x04,0x02,0x00,0x00},/*">",30*/
{0x00,0x00,0x0E,0x11,0x11,0x08,0x04,0x04,0x00,0x04,0x00,0x00},/*"?",31*/
{0x00,0x00,0x0E,0x11,0x19,0x15,0x15,0x1D,0x01,0x1E,0x00,0x00},/*"@",32*/
{0x00,0x00,0x04,0x04,0x0C,0x0A,0x0A,0x1E,0x12,0x33,0x00,0x00},/*"A",33*/
{0x00,0x00,0x0F,0x12,0x12,0x0E,0x12,0x12,0x12,0x0F,0x00,0x00},/*"B",34*/
{0x00,0x00,0x1E,0x11,0x01,0x01,0x01,0x01,0x11,0x0E,0x00,0x00},/*"C",35*/
{0x00,0x00,0x0F,0x12,0x12,0x12,0x12,0x12,0x12,0x0F,0x00,0x00},/*"D",36*/
{0x00,0x00,0x1F,0x12,0x0A,0x0E,0x0A,0x02,0x12,0x1F,0x00,0x00},/*"E",37*/
{0x00,0x00,0x1F,0x12,0x0A,0x0E,0x0A,0x02,0x02,0x07,0x00,0x00},/*"F",38*/
{0x00,0x00,0x1C,0x12,0x01,0x01,0x39,0x11,0x12,0x0C,0x00,0x00},/*"G",39*/
{0x00,0x00,0x33,0x12,0x12,0x1E,0x12,0x12,0x12,0x33,0x00,0x00},/*"H",40*/
{0x00,0x00,0x1F,0x04,0x04,0x04,0x04,0x04,0x04,0x1F,0x00,0x00},/*"I",41*/
{0x00,0x00,0x3E,0x08,0x08,0x08,0x08,0x08,0x08,0x09,0x07,0x00},/*"J",42*/
{0x00,0x00,0x37,0x12,0x0A,0x06,0x0A,0x0A,0x12,0x37,0x00,0x00},/*"K",43*/
{0x00,0x00,0x07,0x02,0x02,0x02,0x02,0x02,0x22,0x3F,0x00,0x00},/*"L",44*/
{0x00,0x00,0x1B,0x1B,0x1B,0x1B,0x15,0x15,0x15,0x15,0x00,0x00},/*"M",45*/
{0x00,0x00,0x3B,0x12,0x16,0x16,0x1A,0x1A,0x12,0x17,0x00,0x00},/*"N",46*/
{0x00,0x00,0x0E,0x11,0x11,0x11,0x11,0x11,0x11,0x0E,0x00,0x00},/*"O",47*/
{0x00,0x00,0x0F,0x12,0x12,0x0E,0x02,0x02,0x02,0x07,0x00,0x00},/*"P",48*/
{0x00,0x00,0x0E,0x11,0x11,0x11,0x11,0x17,0x19,0x0E,0x18,0x00},/*"Q",49*/
{0x00,0x00,0x0F,0x12,0x12,0x0E,0x0A,0x12,0x12,0x37,0x00,0x00},/*"R",50*/
{0x00,0x00,0x1E,0x11,0x01,0x06,0x08,0x10,0x11,0x0F,0x00,0x00},/*"S",51*/
{0x00,0x00,0x1F,0x15,0x04,0x04,0x04,0x04,0x04,0x0E,0x00,0x00},/*"T",52*/
{0x00,0x00,0x33,0x12,0x12,0x12,0x12,0x12,0x12,0x0C,0x00,0x00},/*"U",53*/
{0x00,0x00,0x33,0x12,0x12,0x0A,0x0A,0x0C,0x04,0x04,0x00,0x00},/*"V",54*/
{0x00,0x00,0x15,0x15,0x15,0x0E,0x0A,0x0A,0x0A,0x0A,0x00,0x00},/*"W",55*/
{0x00,0x00,0x1B,0x0A,0x0A,0x04,0x04,0x0A,0x0A,0x1B,0x00,0x00},/*"X",56*/
{0x00,0x00,0x1B,0x0A,0x0A,0x04,0x04,0x04,0x04,0x0E,0x00,0x00},/*"Y",57*/
{0x00,0x00,0x1F,0x09,0x08,0x04,0x04,0x02,0x12,0x1F,0x00,0x00},/*"Z",58*/
{0x00,0x1C,0x04,0x04,0x04,0x04,0x04,0x04,0x04,0x04,0x1C,0x00},/*"[",59*/
{0x00,0x02,0x02,0x02,0x04,0x04,0x08,0x08,0x08,0x10,0x00,0x00},/*"\",60*/
{0x00,0x0E,0x08,0x08,0x08,0x08,0x08,0x08,0x08,0x08,0x0E,0x00},/*"]",61*/
{0x00,0x04,0x0A,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00},/*"^",62*/
{0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x3F},/*"_",63*/
{0x00,0x04,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00},/*"`",64*/
{0x00,0x00,0x00,0x00,0x00,0x0C,0x12,0x1C,0x12,0x3C,0x00,0x00},/*"a",65*/
{0x00,0x00,0x03,0x02,0x02,0x0E,0x12,0x12,0x12,0x0E,0x00,0x00},/*"b",66*/
{0x00,0x00,0x00,0x00,0x00,0x1C,0x12,0x02,0x02,0x1C,0x00,0x00},/*"c",67*/
{0x00,0x00,0x18,0x10,0x10,0x1C,0x12,0x12,0x12,0x3C,0x00,0x00},/*"d",68*/
{0x00,0x00,0x00,0x00,0x00,0x0C,0x12,0x1E,0x02,0x1C,0x00,0x00},/*"e",69*/
{0x00,0x00,0x38,0x04,0x04,0x1E,0x04,0x04,0x04,0x1E,0x00,0x00},/*"f",70*/
{0x00,0x00,0x00,0x00,0x00,0x3C,0x12,0x0C,0x02,0x1E,0x22,0x1C},/*"g",71*/
{0x00,0x00,0x03,0x02,0x02,0x0E,0x12,0x12,0x12,0x37,0x00,0x00},/*"h",72*/
{0x00,0x00,0x04,0x00,0x00,0x06,0x04,0x04,0x04,0x0E,0x00,0x00},/*"i",73*/
{0x00,0x00,0x08,0x00,0x00,0x0C,0x08,0x08,0x08,0x08,0x08,0x07},/*"j",74*/
{0x00,0x00,0x03,0x02,0x02,0x3A,0x0A,0x0E,0x12,0x37,0x00,0x00},/*"k",75*/
{0x00,0x00,0x07,0x04,0x04,0x04,0x04,0x04,0x04,0x1F,0x00,0x00},/*"l",76*/
{0x00,0x00,0x00,0x00,0x00,0x0F,0x15,0x15,0x15,0x15,0x00,0x00},/*"m",77*/
{0x00,0x00,0x00,0x00,0x00,0x0F,0x12,0x12,0x12,0x37,0x00,0x00},/*"n",78*/
{0x00,0x00,0x00,0x00,0x00,0x0C,0x12,0x12,0x12,0x0C,0x00,0x00},/*"o",79*/
{0x00,0x00,0x00,0x00,0x00,0x0F,0x12,0x12,0x12,0x0E,0x02,0x07},/*"p",80*/
{0x00,0x00,0x00,0x00,0x00,0x1C,0x12,0x12,0x12,0x1C,0x10,0x38},/*"q",81*/
{0x00,0x00,0x00,0x00,0x00,0x1B,0x06,0x02,0x02,0x07,0x00,0x00},/*"r",82*/
{0x00,0x00,0x00,0x00,0x00,0x1E,0x02,0x0C,0x10,0x1E,0x00,0x00},/*"s",83*/
{0x00,0x00,0x00,0x04,0x04,0x0E,0x04,0x04,0x04,0x18,0x00,0x00},/*"t",84*/
{0x00,0x00,0x00,0x00,0x00,0x1B,0x12,0x12,0x12,0x3C,0x00,0x00},/*"u",85*/
{0x00,0x00,0x00,0x00,0x00,0x37,0x12,0x0A,0x0C,0x04,0x00,0x00},/*"v",86*/
{0x00,0x00,0x00,0x00,0x00,0x15,0x15,0x0E,0x0A,0x0A,0x00,0x00},/*"w",87*/
{0x00,0x00,0x00,0x00,0x00,0x1B,0x0A,0x04,0x0A,0x1B,0x00,0x00},/*"x",88*/
{0x00,0x00,0x00,0x00,0x00,0x37,0x12,0x0A,0x0C,0x04,0x04,0x03},/*"y",89*/
{0x00,0x00,0x00,0x00,0x00,0x1E,0x08,0x04,0x04,0x1E,0x00,0x00},/*"z",90*/
{0x00,0x18,0x08,0x08,0x08,0x04,0x08,0x08,0x08,0x08,0x18,0x00},/*"{",91*/
{0x08,0x08,0x08,0x08,0x08,0x08,0x08,0x08,0x08,0x08,0x08,0x08},/*"|",92*/
{0x00,0x06,0x04,0x04,0x04,0x08,0x04,0x04,0x04,0x04,0x06,0x00},/*"}",93*/
{0x02,0x25,0x18,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00,0x00} /*"~",94*/
};所以如果刚刚上手一块液晶，首先看通信形式，然后就可以大概浏览函数，当能看出门道时，不妨下载几个程序，生成几个字模试试，也是非常的有趣。