File content as of revision 0:1a55aa7b10a5:

#include "mbed.h"

//10の割り算 0から1028までは、正しい。主に0から999
#define DVI10(n) ((n*205)>>11)

//アナログ入力の設定
AnalogIn adc_vbat(A3); //PA_4
//AnalogIn adc_vbat(A0); //767

#define ADDR_LCD    (0x7C)   //  address

//I2C i2c(I2C_SDA, I2C_SCL); //767
//I2C i2c(dp5, dp27); //1114
I2C i2c(PA_10, PA_9); //010

char    data_read[8];   //i2cバッファー

char INIT_com[]={0x0,0x38,
0x0,0x39,
0x0,0x4,
0x0,0x14,
0x0,0x70,
0x0,0x56,
0x0,0x6C,
0x0,0x38,
0x0,0xC,
0x0,0x1,
0x40,0x41};

char INIT_cls[]={0x0,0x1};

char ch_hex_a_b[5];
char *ch_hex_a(int l_num)
{
    int a,b,c;

    b=DVI10(l_num);
    c=l_num-(b*10);
    l_num=b;
    a=DVI10(l_num);
    b=l_num-(a*10);

    ch_hex_a_b[0] = '@';
    ch_hex_a_b[1] = '0' + a;
    ch_hex_a_b[2] = '0' + b;
    ch_hex_a_b[3] = '0' + c;
    ch_hex_a_b[4] = 0;

    return(ch_hex_a_b);
} //ch_hex_a

int ii;  //ループカウンタ
int s;   //アナログ読み取り値

int main()
{
    //printf("767\r\n"); //767
    //液晶の初期化
    for(ii=0;ii<11;ii++){
        i2c.write(ADDR_LCD, &INIT_com[ii*2], 2);wait_ms(2);
    } //for
    
    //無限ループ
    while (1) {
        //液晶のクリア
        i2c.write(ADDR_LCD,INIT_cls,2);wait_ms(2);

        //adcの読み込み 0から4096
        s = (adc_vbat.read_u16()>>4);
        
        //電圧を温度に変換 ex 20.0 -> 200 温度の十倍を出力
        s=((s-496)*27081)>>16;

        //小数点以上と小数点以下を分ける
        ii=DVI10(s);  // 10の桁
        s =(s-(ii*10))*10; //  1の桁
        
        //温度の小数点以上の表示
        i2c.write(ADDR_LCD, ch_hex_a( ii ) ,4);

       //温度の小数点以下の表示
        ch_hex_a( s );
        ch_hex_a_b[1] = '.';
      //ch_hex_a_b[2] = '0' + s;
        ch_hex_a_b[3] = 'C';
        i2c.write(ADDR_LCD, ch_hex_a_b ,4);

        //1秒待つ
        wait_ms(1000);

    }//while

}//main

//容量削減
void error(const char* format, ...){}