首页 > 代码库 > Zedboard OLED 小演示

Zedboard OLED 小演示

2024-07-12 17:27:00   224人阅读

玩Zedboard上自带的OLED，网上一位博主对这颗OLED做了比较底层的分析和开发。http://blog.chinaaet.com/detail/30962 。程序和硬件构思基本移植了在单片机开发上的经验。大致的想法是用PL部分搭建OLED控制和通讯的SPI协议，再通过PS控制发送OLED需要显示的信息。有兴趣可以展开看一下。不过Diligent为OLED已经制作好了驱动，正如我们在用SD卡启动时看到的Diligent的logo。我们可以基于此做一些简单的演示开发。这里借助img2lcd工具，可以轻松实现一些DIY的图型显示。

简单的原理说明，OLED与Zync芯片之间通过SPI接口连接，在此我们先忽略之间的驱动细节。 Diligent为我们做好了驱动程序，并一个驱动映射为/dev/zed_oled。我们只需将数据压入这个文件，就可以在OLED上显示需要的图像。在用ramdisk方式启动zedboard时，可以找到 load_oled的脚本程序。打开可以看到里面的内容是这样的。

#!/bin/shinsmod /lib/modules/`uname -r`/pmodoled-gpio.ko;if [ -c /dev/zed_oled ]; then        cat /root/logo.bin > /dev/zed_oled;fi;

据此可以理解这里进行了两步操作，insmod命令安装了oled的驱动pmodoled-gpio.ko，紧接着用cat xx.bin > /dev/zed_oled 写入图像的二进制数据，完成显示。

于是我们可以用 img2lcd 工具把需要显示的图像转化成.bin文件，然后放入SD卡cat一下就OK了。设置如下图，选择输出数据类型*.bin，扫描模式：数据水平-位元垂直，宽高为128*32，勾选位元组内像素倒序+自底至顶扫描。可以简单玩一下各种组合，看一下显示有什么变化，也可以帮助理解这颗OLED是怎么工作的。

 

保存之后就可以得到我们需要的*.bin文件了，这里存成oed1.bin。copy至SD卡，然后运行命令。

cat /root/oled1.bin > /dev/zed_oled;

静态的显示就这么轻松的搞定了，是不是可以做一些炫酷的动态演示？当然可以。

一个简单的例子，按照上面的流程，在img2lcd工具上保持其他的设置不变，勾选颜色反转。保存成oled2.bin。copy到SD卡。创建如下的一个shell脚本（注意修改*.bin文件的所在目录）。运行一下看一下效果吧。

#!/bin/bashwhile truedo    cat /root/oled1.bin > /dev/zed_oled    sleep 1    cat /root/oled2.bin > /dev/zed_oled    sleep 1done

除了用shell，我们也可以用其他的程序来搞定OLED的显示。以下以C为例。

还是回到img2lcd里，选择输出数据类型C语言数组*.c。保存之后会弹出文本文档，显示一个16进制的数组。这个数组就是图像转化成的像素信息了。根据这个数组开始编写C程序。

#include <stdio.h>#include <stdlib.h>#include <sys/types.h>#include <fcntl.h>#include <unistd.h>unsigned char dis_buf[128*4]={0};const unsigned char gImage_oled1[512] = { /* 0X62,0X01,0X80,0X00,0X20,0X00, */0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X38,0X78,0X78,0XF8,0XB8,0X38,0X38,0X38,0X38,0X38,0X00,0X00,0XF0,0XF0,0XF0,0XB0,0XB0,0XB0,0X60,0X00,0X00,0XF0,0XF0,0X30,0X30,0X30,0X30,0XF0,0XE0,0X00,0X30,0XF0,0XB0,0X30,0X30,0X30,0X60,0XE0,0X80,0X00,0XF0,0XF8,0X38,0X30,0X30,0X60,0XC0,0X80,0X70,0XF0,0XF8,0X38,0X30,0X30,0XF8,0XF0,0X00,0X78,0XF0,0XC0,0X00,0X00,0X00,0X00,0X00,0XE0,0XF0,0X30,0X30,0X30,0X30,0XF0,0XF0,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X70,0XF8,0XB8,0X18,0X18,0X38,0X30,0X70,0XE0,0XC0,0X00,0XE0,0XF0,0XF0,0XB0,0XB0,0XB0,0X30,0X60,0X00,0X78,0XF0,0X80,0X00,0X18,0XF8,0XE0,0X00,0X00,0XF8,0XF0,0X80,0X60,0XF0,0XF8,0X38,0X30,0X30,0XE0,0XC0,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X40,0XE1,0XE3,0XE6,0XEC,0XF8,0XF8,0XF0,0XE0,0XE1,0X43,0X07,0X0E,0X0D,0X0D,0X0F,0X0E,0X04,0X01,0X03,0X06,0X0E,0X0C,0X0C,0X0F,0X0F,0X3E,0XF8,0XC1,0X0F,0X7E,0XEC,0X8C,0X0C,0X0F,0X07,0X00,0X01,0X03,0X07,0X0E,0X0C,0X0C,0X0F,0X07,0X00,0X01,0X03,0X06,0X0E,0X0C,0X0D,0X0F,0X0E,0X00,0X03,0X0F,0X0E,0X06,0X0C,0X0F,0X0F,0X0C,0X03,0X07,0X06,0X0C,0X0C,0X0C,0X0F,0X1F,0XF8,0XE0,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X03,0X1F,0X7C,0XE0,0XE0,0X70,0X70,0X38,0X1F,0X0F,0X00,0X03,0X07,0X06,0X0D,0X0D,0X0F,0X0F,0X06,0X00,0X03,0X0F,0X1F,0X06,0X0D,0X0F,0X0E,0X0E,0X0C,0X0F,0X0F,0X00,0X01,0X03,0X06,0X0C,0X0C,0X0E,0X0F,0X07,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,0X00,};int main(){  int fd = open("/dev/zed_oled",O_RDWR);  int i,j,m;  if( fd == -1){    printf("Can‘t open zed_oled device!\n");    return 0;  }  else{    printf("/dev/zed_oled open success!\n");  }        for(i=0; i<512 ; i++){       dis_buf[i]=gImage_oled1[i];     }while (1) {        unsigned char temp[4] = {0};    temp[3] = dis_buf[384];    temp[2] = dis_buf[256];    temp[1] = dis_buf[128];    temp[0] = dis_buf[0];         for(j=0;j<4;j++){　　　　　　for (m=0;m<127;m++){　　　　　　　　dis_buf[128*j+m]=dis_buf[128*j+m+1];　　　　　　　　}    }    dis_buf[511] = temp[3];    dis_buf[383] = temp[2];    dis_buf[255] = temp[1];    dis_buf[127] = temp[0];    sleep(1);    write(fd,dis_buf,128*4);     }      return 0;}

 

copy到SD卡上，在boot之后再编译运行一下，看到什么了？哈哈，搞定！

一个问题，为什么这里的数组是128*4=512呢？可以留作思考吧，哈。

这个C程序的移位算法不够优化只是做简单的演示，更多数组移位的优化算法可以参考此链接 http://blog.csdn.net/hackbuteer1/article/details/6699837


联系
我们