ST7735 TFT显示屏 显示问题 |
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ST7735 TFT显示屏 显示问题
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1. 叙述
许久未使用的TFT显示屏，这些天突然想使用它来竖屏显示，在查阅数据手册后设置成功，加上还有一些颜色显示问题，一并记录。首先看数据手册的寄存器功能位描述 数据手册
由于一开始的色块刷新函数适用于的初始化时(36h)寄存器位置写入的值为(1100_0000),也就是上图的第四个，注意上图的三位数据和(MV MX MY)与实际寄存器顺序不一样 X-Y 坐标交换: 与DDRAM中的正常数据显示模式相比，就是X和Y的数据对调了 X-Mirror: 与DDRAM中正常的模式相比，为X轴对称 Y-Mirror： 与与DDRAM中正常的模式相比，为Y轴对称 至于为啥采用第四种竖屏 显示，而不是正常模式，由于模块正常模式是反着的，不好看。 若是需要改为横屏 显示，而且还能够使用原来的刷屏函数，那就要向寄存器中写入(0110_0000) 三种显示效果如下所示，由于屏幕亮度太高，文字显示不出来。2是正常显示，1是第四种显示，3是横屏显示 至于颜色错乱问题，如红色显示成了蓝色，是由于(36h)寄存器的RGB位被置1了，所以RGB数据被显示成了BGR。 2.代码初始化的代如下所示，其实就只改了一行。 void Lcd_Init() { LCD_GPIO_Init(); Lcd_Reset(); Lcd_WriteIndex(0x11);//Sleep exit Lcd_DelayMs (120); //ST7735R Frame Rate Lcd_WriteIndex(0xB1); Lcd_WriteData(0x01); Lcd_WriteData(0x2C); Lcd_WriteData(0x2D); Lcd_WriteIndex(0xB2); Lcd_WriteData(0x01); Lcd_WriteData(0x2C); Lcd_WriteData(0x2D); Lcd_WriteIndex(0xB3); Lcd_WriteData(0x01); Lcd_WriteData(0x2C); Lcd_WriteData(0x2D); Lcd_WriteData(0x01); Lcd_WriteData(0x2C); Lcd_WriteData(0x2D); Lcd_WriteIndex(0xB4); //Column inversion Lcd_WriteData(0x07); //ST7735R Power Sequence Lcd_WriteIndex(0xC0); Lcd_WriteData(0xA2); Lcd_WriteData(0x02); Lcd_WriteData(0x84); Lcd_WriteIndex(0xC1); Lcd_WriteData(0xC5); Lcd_WriteIndex(0xC2); Lcd_WriteData(0x0A); Lcd_WriteData(0x00); Lcd_WriteIndex(0xC3); Lcd_WriteData(0x8A); Lcd_WriteData(0x2A); Lcd_WriteIndex(0xC4); Lcd_WriteData(0x8A); Lcd_WriteData(0xEE); Lcd_WriteIndex(0xC5); //VCOM Lcd_WriteData(0x0E); //屏幕横竖问题未解决 已解决 写入0x60 Lcd_WriteIndex(0x36); //MX, MY, RGB mode //Lcd_WriteData(0xC0); //竖屏 Lcd_WriteData(0x60); //横屏 //ST7735R Gamma Sequence Lcd_WriteIndex(0xe0); Lcd_WriteData(0x0f); Lcd_WriteData(0x1a); Lcd_WriteData(0x0f); Lcd_WriteData(0x18); Lcd_WriteData(0x2f); Lcd_WriteData(0x28); Lcd_WriteData(0x20); Lcd_WriteData(0x22); Lcd_WriteData(0x1f); Lcd_WriteData(0x1b); Lcd_WriteData(0x23); Lcd_WriteData(0x37); Lcd_WriteData(0x00); Lcd_WriteData(0x07); Lcd_WriteData(0x02); Lcd_WriteData(0x10); Lcd_WriteIndex(0xe1); Lcd_WriteData(0x0f); Lcd_WriteData(0x1b); Lcd_WriteData(0x0f); Lcd_WriteData(0x17); Lcd_WriteData(0x33); Lcd_WriteData(0x2c); Lcd_WriteData(0x29); Lcd_WriteData(0x2e); Lcd_WriteData(0x30); Lcd_WriteData(0x30); Lcd_WriteData(0x39); Lcd_WriteData(0x3f); Lcd_WriteData(0x00); Lcd_WriteData(0x07); Lcd_WriteData(0x03); Lcd_WriteData(0x10); Lcd_WriteIndex(0x2a); Lcd_WriteData(0x00);Lcd_WriteData(0x00); Lcd_WriteData(0x00);Lcd_WriteData(0x7f); Lcd_WriteIndex(0x2b); Lcd_WriteData(0x00);Lcd_WriteData(0x00); Lcd_WriteData(0x00);Lcd_WriteData(0x9f); Lcd_WriteIndex(0xF0); //Enable test command Lcd_WriteData(0x01); Lcd_WriteIndex(0xF6); //Disable ram power save mode Lcd_WriteData(0x00); Lcd_WriteIndex(0x3A); //65k mode Lcd_WriteData(0x05); Lcd_WriteIndex(0x29);//Display on } //对应的设置显示区代码 void Lcd_SetRegion(u16 x_start,u16 y_start,u16 x_end,u16 y_end) { #ifdef USE_DMA //修改后，为使用DMA 加速SPI2传输数据(刷屏) Lcd_WriteIndex(0x2A); Lcd_WriteData16(x_start); Lcd_WriteData16(x_end); Lcd_WriteIndex(0x2B); Lcd_WriteData16(y_start); Lcd_WriteData16(x_end); //采用DMA搬运时需要使用x_end，很奇怪 Lcd_WriteIndex(0x2C); #else //正常显示 Lcd_WriteIndex(0x2a); Lcd_WriteData(0x00); Lcd_WriteData(x_start); Lcd_WriteData(0x00); Lcd_WriteData(x_end); Lcd_WriteIndex(0x2b); Lcd_WriteData(0x00); Lcd_WriteData(y_start); Lcd_WriteData(0x00); Lcd_WriteData(y_end); Lcd_WriteIndex(0x2c); #endif } 3.总结本次主要是在使用littvgl 开源GUI显示图片时发现图片显示颜色出现了问题，开始以为是GUI移植过程出了问题，后来在直接操作屏幕显示发现颜色也不对，便找到了相关的数据手册细看了(36h)这一寄存器的说明，最后定位到了初始化的问题上。本人不才，必有疏漏，望指正。 注意！！！ 下载资源 UCOSIII+LittleVGL+DMA刷新屏幕 的朋友，会出现颜色显示不对的问题，需要将原来初始化代码中的 Lcd_WriteData(0x68); //横屏 改为 Lcd_WriteData(0x68) 自己上传的资源不允许修改和评论，这也是**操作，抱歉了。 |
再看一下不同设置方法的理论显示效果 
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