MLX90640 紅外熱成像儀測(cè)溫模塊開(kāi)發(fā)筆記（二）API 移植-I2C 和關(guān)鍵接口函數(shù) 

API 說(shuō)明文件里面有官方的移植指導(dǎo)，但我覺(jué)得可以把重點(diǎn)放在與 MLX90640 具體操作有關(guān)的幾個(gè)函數(shù)上，而與標(biāo)準(zhǔn) I2C 相關(guān)的函數(shù)和文件結(jié)構(gòu)還是按照自己習(xí)慣的套路實(shí)現(xiàn)。這樣更符合我們開(kāi)發(fā)人員的可控性的習(xí)慣。步驟如下：

（1）建立標(biāo)準(zhǔn) I2C 文件 IIC.h 和 IIC.c 

用自己的方法實(shí)現(xiàn)如下幾個(gè)函數(shù)（硬件也好，GPIO 模擬也好），函數(shù)名稱(chēng)用下面建議的。

void IIC_Init(void);//I2C 接口初始化

void IIC_Start(void);//發(fā)送開(kāi)始信號(hào)

void IIC_Stop(void);//發(fā)送結(jié)束信號(hào)

void IIC_SendACK(void);//發(fā)送應(yīng)答信號(hào)

void IIC_SendNAK(void);//發(fā)送非應(yīng)答信號(hào)unsigned char IIC_RecvACK(void);//讀取應(yīng)答信號(hào)unsigned char IIC_RecvData(void);//讀取 1 個(gè)字節(jié)void IIC_SendData(char dat);//發(fā)送 1 個(gè)字節(jié)

（2）在工程中引入 MLX90640_API.c 

并做如下幾處修改

第一行#include <MLX90640_I2C_Driver.h>改為#include <IIC.h>

（3）添加 3 個(gè)函數(shù) 

void MLX90640_I2CInit(void)

unsigned char MLX90640_I2CRead (unsigned short startAddress, unsigned short nWordsRead, unsigned short *datas)

unsigned char MLX90640_I2CWrite (unsigned short writeAddress, unsigned short word)

void MLX90640_I2CInit(void)

{

IIC_Stop();

}

//從指定地址讀取 n 個(gè)字（每個(gè)字占用 2 個(gè)字節(jié)）

unsigned char MLX90640_I2CRead(unsigned short startAddress, unsigned short nWordsRead, unsigned short *datas)

{

unsigned char c1,c2; unsigned short i; unsigned char Msb,Lsb;

Msb=(unsigned char)(startAddress>>8); Lsb=(unsigned char)(startAddress&0x00FF);

IIC_Start();//發(fā)送起始命令

IIC_SendData(0x66);//發(fā)送設(shè)備地址+寫(xiě)命令I(lǐng)IC_RecvACK();

IIC_SendData(Msb);//發(fā)送要操作的地址值 2 字節(jié)

IIC_RecvACK();

IIC_SendData(Lsb);

IIC_RecvACK();

IIC_Start();//發(fā)送起始命令

IIC_SendData(0x67);//發(fā)送設(shè)備地址+讀命令I(lǐng)IC_RecvACK();

for (i=0;i<nWordsRead;i++)

{

c1=IIC_RecvData(); IIC_SendACK();

c2=IIC_RecvData();

if (i==(nWordsRead-1)) IIC_SendNAK();

else

IIC_SendACK();

datas[i]=c1; datas[i]<<=8; datas[i]|=c2;

}

IIC_Stop();//發(fā)送停止命令

return 0;

}

//向指定地址寫(xiě)入 1 個(gè)字（2 字節(jié)）

unsigned char MLX90640_I2CWrite(unsigned int writeAddress, unsigned int word)

{

IIC_Start();//發(fā)送起始命令

IIC_SendData(0x66);//發(fā)送設(shè)備地址+寫(xiě)命令I(lǐng)IC_RecvACK();

IIC_SendData(writeAddress>>8);//發(fā)送要操作的地址值 2 字節(jié)

IIC_RecvACK();

IIC_SendData(writeAddress&0x00FF); IIC_RecvACK();

IIC_SendData(word>>8); IIC_RecvACK();

IIC_SendData(word&0x00FF); IIC_RecvACK();

IIC_Stop(); return 0;

（4）修改 2 個(gè)函數(shù) 

unsigned char MLX90640_DumpEE(unsigned short *eeData)

{

return MLX90640_I2CRead(0x2400, 832, eeData);

}

unsigned char MLX90640_GetFrameData(unsigned short *frameData)

{

unsigned short statusRegister,controlRegister1;

MLX90640_I2CRead(0x8000, 1, &statusRegister); if (statusRegister&0x0008)//有測(cè)量完成的 Frame

{

MLX90640_I2CRead(0x800D, 1, &controlRegister1); MLX90640_I2CWrite(0x8000, statusRegister&(~0x0018)); MLX90640_I2CRead(0x0400, 832, frameData); frameData[832] = controlRegister1;

frameData[833] = statusRegister & 0x0001; return 0;

}

Return -1;

}

至此移植完成

編譯工程，若沒(méi)有錯(cuò)誤提示則基本上沒(méi)有問(wèn)題了，下一篇開(kāi)始講述如何操作MLX90640。