bmp to Hex——图片在单片机上显示

摘要

我通过在网上寻找工具及借鉴开源社区留言，探索出一种位图转二进制写入单片机的工作流程

流水帐式流程

1. 使用开源的GIMP处理图像为128x53的16bit二值化BMP文件
2. 我找到一个开源工具，使用Monochrome预设导出图片，其内置大小端设置，但其将2byte作为最小粒度

   https://github.com/riuson/lcd-image-converter

3. 显示不正常，可感受到以一小块为单位左右割裂颠倒。网上找到一个帖子描述了这种现象的成因。

   https://forum.arduino.cc/t/solved-problem-drawing-bmp-in-oled-i2c-ssd1306-with-esp8266/417698/11

4. 文章锁定前最后一个大佬给出了一个c程序，但我用不了
5. 我上手修改，重拾大一下c++，用到了当时不懂现在还不懂的动态内存和指针

   C++代码

   //Origin:https://forum.arduino.cc/t/solved-problem-drawing-bmp-in-oled-i2c-ssd1306-with-esp8266/417698/11
   //Some changes were made on the basis of the original version, which did not work properly on my VS2010
   //MIT Lisences By:Zhaosn
   #include <stdio.h>
   
   const char myBitmap[] = { //this is the array char
   	0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
   };
   char inverter(char val){ // this function invert the value
   	char ret;
   	char a = (val & 0x01)<<7;
   	char b = (val & 0x02)<<5;
   	char c = (val & 0x04)<<3;
   	char d = (val & 0x08)<<1;
   	char e = (val & 0x10)>>1;
   	char f = (val & 0x20)>>3;
   	char g = (val & 0x40)>>5;
   	char h = (val & 0x80)>>7;
   
   	ret = a|b|c|d|e|f|g|h;
   	return ret;
   }
   int main(void){
   
   	int size = sizeof(myBitmap);// myBitmap is the name for our array char
   	char *values = NULL;
   	int count = 0;
   	values = new char [size];
   	for(int i = 0 ; i < size; i++){
   		values[i] = inverter(myBitmap[i]); // here we revert each value;*
   		printf("0x%02x",(unsigned char)values[i]); //need "(unsigned char)" or it will display as "0xffffffxx". It is "2's complement".
   		if(count == 15){
   			printf(",\n");
   			count = 0;
   		} else if(i == size-1){
   			printf("\n");
   		} else {
   			printf(", ");
   			count++;
   		}
   	}
   	delete values;
   }