书接上文:
最近在研究用低速、低RAM的单片机来驱动小LCD或TFT彩屏实现动画效果
首先我用一个16MHz晶振的m0内核的8位单片机nRF51822尝试驱动一个1.77寸的4线SPI屏(128X160),
发现,刷一屏大约要0.8s左右的时间,
具体收录在《1、一个简单的nRF51822驱动的天马4线SPI-1.77寸LCD彩屏DEMO》中
觉得,如果用72MHz的STM32也许效果会好很多
于是在stm32上做了个类似的版本,
具体收录在《一个简单的stm32vet6驱动的天马4线SPI-1.77寸LCD彩屏DEMO》中
发现刷一屏0.2s左右,
效果是有的,但是还不能达到支持播放流畅动画的效果!
于是,决定将串行数据改成并行数据传输
本节将带来一个用stm32驱动的2.4寸240X320的8位并口tft屏的刷屏效果
工程结构
main.c
1 /* Includes ------------------------------------------------------------------*/
2 #include "stm32f10x.h"
3 #include "LCD2.h"
4
5
6 void RCC_Configuration(void);
7 /****************************************************************************
8 * 名 称:int main(void)
9 * 功 能:主函数
10 * 入口参数:无
11 * 出口参数:无
12 * 说 明:
13 * 调用方法:无
14 ****************************************************************************/
15 int main(void)
16 {
17 RCC_Configuration(); //系统时钟配置
18 LCD2_GPIO_Init();
19 LCD2_Init();
20 while (1)
21 {
22 Show_RGB(0,240,0,320,0xff0f);
23 DELAY_MS(1000);
24 Show_RGB(0,240,0,320,0x00fe);
25 DELAY_MS(1000);
26 }
27 }
28
29 /****************************************************************************
30 * 名 称:void RCC_Configuration(void)
31 * 功 能:系统时钟配置为72MHZ
32 * 入口参数:无
33 * 出口参数:无
34 * 说 明:
35 * 调用方法:无
36 ****************************************************************************/
37 void RCC_Configuration(void)
38 {
39 SystemInit();
40 }
LCD2.c
1 #include "LCD2.h"
2
3
4
5 void LCD2_GPIO_Init()
6 {
7 GPIO_InitTypeDef GPIO_InitStructure;
8
9 RCC_APB2PeriphClockCmd(RCC_APB2Periph_GPIOB | RCC_APB2Periph_GPIOD | RCC_APB2Periph_AFIO, ENABLE);
10
11
12 GPIO_InitStructure.GPIO_Pin = GPIO_Pin_6 | GPIO_Pin_7 | GPIO_Pin_8 | GPIO_Pin_9;
13 GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP;
14 GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz; //口线翻转速度为50MHz
15 GPIO_Init(GPIOB, &GPIO_InitStructure);
16
17 //8位数据输出
18 GPIO_InitStructure.GPIO_Pin = GPIO_Pin_0 | GPIO_Pin_1 | GPIO_Pin_2 | GPIO_Pin_3 | GPIO_Pin_4 | GPIO_Pin_5 | GPIO_Pin_6 | GPIO_Pin_7;
19 GPIO_InitStructure.GPIO_Mode = GPIO_Mode_Out_PP;
20 GPIO_InitStructure.GPIO_Speed = GPIO_Speed_50MHz; //口线翻转速度为50MHz
21 GPIO_Init(GPIOD, &GPIO_InitStructure);
22 }
23
24 //////////////////////////////////////////////////////////////////
25 //最底层数据传输函数
26 //////////////////////////////////////////////////////////////////
27 //写命令
28 void Write_Cmd(unsigned char DH,unsigned char DL)
29 {
30 LCD2_CS=0;
31 LCD2_RS=0;
32
33 DataPort=DH;
34 LCD2_RW=0;
35 LCD2_RW=1;
36
37 DataPort=DL;
38
39 LCD2_RW=0;
40 LCD2_RW=1;
41 LCD2_CS=1;
42 }
43 //写数据 双8位
44 void Write_Data(unsigned char DH,unsigned char DL)
45 {
46 LCD2_CS=0;
47
48 LCD2_RS=1;
49 DataPort=DH;
50 LCD2_RW=0;
51 LCD2_RW=1;
52
53 DataPort=DL;
54 LCD2_RW=0;
55 LCD2_RW=1;
56 LCD2_CS=1;
57 }
58
59 //写数据 双8位
60 void Write_Data2(unsigned char DH,unsigned char DL)
61 {
62 DataPort=DH;
63 LCD2_RW=0;
64 LCD2_RW=1;
65
66 DataPort=DL;
67 LCD2_RW=0;
68 LCD2_RW=1;
69 }
70
71 //////////////////////////////////////////////////////////////////
72 //调用上面最底层实现稍高层写命令和数据函数
73 //////////////////////////////////////////////////////////////////
74 /*----------------------------------------------------------------
75 写命令、写数据
76 输入参数:x 需要输入的命令 16位
77 y 需要输入的数据 16位
78 ----------------------------------------------------------------*/
79 void Write_Cmd_Data (unsigned char x,unsigned int y)
80 {
81 unsigned char m,n;
82 m=y>>8;
83 n=y;
84 Write_Cmd(0x00,x);
85 Write_Data(m,n);
86 }
87 /*----------------------------------------------------------------
88 写16位数据
89 ----------------------------------------------------------------*/
90 void Write_Data_U16(unsigned int y)
91 {
92 unsigned char m,n;
93 m=y>>8;
94 n=y;
95 Write_Data2(m,n);
96 }
97
98 /*----------------------------------------------------------------
99 液晶初始化
100 ----------------------------------------------------------------*/
101 void LCD2_Init(void)
102 {
103 LCD2_CS=1;
104 DELAY_MS(5);
105 LCD2_RES=0;
106 DELAY_MS(5);
107 LCD2_RES=1;
108 DELAY_MS(50);
109 Write_Cmd_Data(0x0001,0x0100);
110 Write_Cmd_Data(0x0002,0x0700);
111 Write_Cmd_Data(0x0003,0x1030);
112 Write_Cmd_Data(0x0004,0x0000);
113 Write_Cmd_Data(0x0008,0x0207);
114 Write_Cmd_Data(0x0009,0x0000);
115 Write_Cmd_Data(0x000A,0x0000);
116 Write_Cmd_Data(0x000C,0x0000);
117 Write_Cmd_Data(0x000D,0x0000);
118 Write_Cmd_Data(0x000F,0x0000);
119 //power on sequence VGHVGL
120 Write_Cmd_Data(0x0010,0x0000);
121 Write_Cmd_Data(0x0011,0x0007);
122 Write_Cmd_Data(0x0012,0x0000);
123 Write_Cmd_Data(0x0013,0x0000);
124 //vgh
125 Write_Cmd_Data(0x0010,0x1290);
126 Write_Cmd_Data(0x0011,0x0227);
127 //DELAY_MS(100);
128 //vregiout
129 Write_Cmd_Data(0x0012,0x001d); //0x001b
130 //DELAY_MS(100);
131 //vom amplitude
132 Write_Cmd_Data(0x0013,0x1500);
133 //DELAY_MS(100);
134 //vom H
135 Write_Cmd_Data(0x0029,0x0018);
136 Write_Cmd_Data(0x002B,0x000D);
137
138 //gamma
139 Write_Cmd_Data(0x0030,0x0004);
140 Write_Cmd_Data(0x0031,0x0307);
141 Write_Cmd_Data(0x0032,0x0002);// 0006
142 Write_Cmd_Data(0x0035,0x0206);
143 Write_Cmd_Data(0x0036,0x0408);
144 Write_Cmd_Data(0x0037,0x0507);
145 Write_Cmd_Data(0x0038,0x0204);//0200
146 Write_Cmd_Data(0x0039,0x0707);
147 Write_Cmd_Data(0x003C,0x0405);// 0504
148 Write_Cmd_Data(0x003D,0x0F02);
149 //ram
150 Write_Cmd_Data(0x0050,0x0000);
151 Write_Cmd_Data(0x0051,0x00EF);
152 Write_Cmd_Data(0x0052,0x0000);
153 Write_Cmd_Data(0x0053,0x013F);
154 Write_Cmd_Data(0x0060,0xA700);
155 Write_Cmd_Data(0x0061,0x0001);
156 Write_Cmd_Data(0x006A,0x0000);
157 //
158 Write_Cmd_Data(0x0080,0x0000);
159 Write_Cmd_Data(0x0081,0x0000);
160 Write_Cmd_Data(0x0082,0x0000);
161 Write_Cmd_Data(0x0083,0x0000);
162 Write_Cmd_Data(0x0084,0x0000);
163 Write_Cmd_Data(0x0085,0x0000);
164 //
165 Write_Cmd_Data(0x0090,0x0010);
166 Write_Cmd_Data(0x0092,0x0600);
167 Write_Cmd_Data(0x0093,0x0003);
168 Write_Cmd_Data(0x0095,0x0110);
169 Write_Cmd_Data(0x0097,0x0000);
170 Write_Cmd_Data(0x0098,0x0000);
171 Write_Cmd_Data(0x0007,0x0133);
172
173 // Write_Cmd_Data(0x0022);//
174 }
175
176 /*----------------------------------------------------------------
177 设置坐标
178 ----------------------------------------------------------------*/
179 /*----------------------------------------------------------------
180 全局变量
181 ----------------------------------------------------------------*/
182 #define WINDOW_XADDR_START 0x0050 // Horizontal Start Address Set
183 #define WINDOW_XADDR_END 0x0051 // Horizontal End Address Set
184 #define WINDOW_YADDR_START 0x0052 // Vertical Start Address Set
185 #define WINDOW_YADDR_END 0x0053 // Vertical End Address Set
186 #define GRAM_XADDR 0x0020 // GRAM Horizontal Address Set
187 #define GRAM_YADDR 0x0021 // GRAM Vertical Address Set
188 #define GRAMWR 0x0022 // memory write
189 void LCD_SetPos(unsigned int x0,unsigned int x1,unsigned int y0,unsigned int y1)
190 {
191 Write_Cmd_Data(WINDOW_XADDR_START,x0);
192 Write_Cmd_Data(WINDOW_XADDR_END,x1);
193 Write_Cmd_Data(WINDOW_YADDR_START,y0);
194 Write_Cmd_Data(WINDOW_YADDR_END,y1);
195 Write_Cmd_Data(GRAM_XADDR,x0);
196 Write_Cmd_Data(GRAM_YADDR,y0);
197 Write_Cmd (0x00,0x22);//LCD_WriteCMD(GRAMWR);
198 }
199
200 /*----------------------------------------------------------------
201 显示RGB颜色
202 输入参数:x0,y0 起始坐标
203 x1,y1 结束坐标
204 Color 背景颜色
205 ----------------------------------------------------------------*/
206 void Show_RGB (unsigned int x0,unsigned int x1,unsigned int y0,unsigned int y1,unsigned int Color)
207 {
208 unsigned int i,j;
209 LCD_SetPos(x0,x1,y0,y1);
210 LCD2_CS=0;
211 LCD2_RS=1;
212 // for (i=y0;i<=y1;i++)
213 // {
214 // for (j=x0;j<=x1;j++)
215 // Write_Data_U16(Color);
216 // }
217
218 for (i=0;i<=(y1-y0+1)*(x1-x0+1);i+=32)
219 {
220 Write_Data_U16(Color);
221 Write_Data_U16(Color);
222 Write_Data_U16(Color);
223 Write_Data_U16(Color);
224 Write_Data_U16(Color);
225 Write_Data_U16(Color);
226 Write_Data_U16(Color);
227 Write_Data_U16(Color);
228 Write_Data_U16(Color);
229 Write_Data_U16(Color);
230 Write_Data_U16(Color);
231 Write_Data_U16(Color);
232 Write_Data_U16(Color);
233 Write_Data_U16(Color);
234 Write_Data_U16(Color);
235 Write_Data_U16(Color);
236 Write_Data_U16(Color);
237 Write_Data_U16(Color);
238 Write_Data_U16(Color);
239 Write_Data_U16(Color);
240 Write_Data_U16(Color);
241 Write_Data_U16(Color);
242 Write_Data_U16(Color);
243 Write_Data_U16(Color);
244 Write_Data_U16(Color);
245 Write_Data_U16(Color);
246 Write_Data_U16(Color);
247 Write_Data_U16(Color);
248 Write_Data_U16(Color);
249 Write_Data_U16(Color);
250 Write_Data_U16(Color);
251 Write_Data_U16(Color);
252 }
253 LCD2_CS=1;
254 }
255
256
257 void Delay_ms(u16 time)
258 {
259 u16 i=0;
260 while(time--)
261 {
262 i=12000;
263 while(i--);
264 }
265 }
注:代码比较容易理解,不做详解
另外补上这三个小实验的连线图:
1、这个是本节的并行接口与屏幕的连接方式:
2、这是上两节串行接口的连线,上面对应的引脚连接是与nRF51822的(第一次试验),下面对应的连接是与stm32的(第二次试验)
小结
从效果图上看,即使采用stm32的8位并行来驱动屏幕速度还是达不到刷新动画的效果~
之后我也在传输数据的函数上做了些优化,可效果还是不明显——
如第一点:优化前RS等引脚的定义要通过宏展开,每次计算BitBand后面的式子~
1 #define BitBand(Addr, Bit) *((volatile int*)(((int)(Addr) & 0x60000000) + 0x02000000 + (int)(Addr) * 0x20 + (Bit) * 4))
2 #define LCD2_CS BitBand(&GPIOB->ODR, 8)
3 #define LCD2_RES BitBand(&GPIOB->ODR, 9)
4 #define LCD2_RS BitBand(&GPIOB->ODR, 7)
5 #define LCD2_RW BitBand(&GPIOB->ODR, 6)
6 #define DataPort GPIOD->ODR
优化后采用直接把值赋给对应的引脚来减少运算量
1 #define BitBand(Addr, Bit) *((volatile int*)(((int)(Addr) & 0x60000000) + 0x02000000 + (int)(Addr) * 0x20 + (Bit) * 4))
2 #define LCD2_CS (*((volatile int*)0x422181A0)) //BitBand(&GPIOB->ODR, 8)
3 #define LCD2_RES (*((volatile int*)0x422181A4)) //BitBand(&GPIOB->ODR, 9)
4 #define LCD2_RS (*((volatile int*)0x4221819C)) //BitBand(&GPIOB->ODR, 7)
5 #define LCD2_RW (*((volatile int*)0x42218198)) //BitBand(&GPIOB->ODR, 6)
6 #define DataPort (*((volatile int*)0x4001140C)) //GPIOD->ODR
如第二点:为了减少Show_RGB函数中循环中的Write_Data_U16的调用,直接将Write_Data_U16计算拆到最细放到循环内
如第三点:为了排除Write_Data_U16中4、5两行移位运算和类型转换所带来的时间花销,直接采用上图中全局变量color1、color2来直接赋值,查看效果有没有提升~
1 void Write_Data_U16(unsigned int y)
2 {
3 unsigned char m,n;
4 m=y>>8;
5 n=y;
6 Write_Data2(m,n);
7 }
本篇中资源链接:http://pan.baidu.com/s/1bnjw1Fh
注:其中未优化版工程比较简洁方便理解学习,优化测试版是为了提升传输速率做的几点优化(效果不大,代码稍乱)
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