最近将部分在应用程序上验证通过的代码移植到bootloader上,发现与预期结果不同,比较奇怪;
应用端代码如下:
static float inputVolt1 = 1.240; //set at first
static float inputVolt2 = 2.313; //set at first
static void calculateReferVolt(u16 reg1, u16 reg2)
{
float k=0.000;
float b=0.000;
u32 u32_k = 0;
u32 u32_b = 0;
k = (inputVolt2 - inputVolt1)*8192*1.2/(reg2-reg1);
b = (inputVolt1 - (reg1 - 8192)*(inputVolt2 - inputVolt1)/(reg2 - reg1));
printf("k: %.4f\r\n", k);
printf("b: %.4f\r\n", b);
u32_k = k*10000;
u32_b = b*10000;
tls_fls_write(ADDR_K, (char*)&u32_k, 4);
tls_fls_write(ADDR_B, (char*)&u32_b, 4);
}
以上代码在应用代码中验证可用,计算出来的k & b的值也与预期相符,但是将其移植到bootloader中以后,发现计算出来的k & b的值不对,也很奇怪,没找到原因。最后通过将两个全局变量修改成宏,才得出正确的k & b的值。定义成宏以后,编译阶段会完成一部分计算,应该与此有关,具体的没去深究。移植并修改后的代码如下:
#define INPUT_VOLTAGE_1 0.4
#define INPUT_VOLTAGE_2 3.0
static void calculateReferVolt(u16 reg1, u16 reg2)
{
float k=0.000;
float b=0.000;
u32 refer_k = 0;
u32 offset_b = 0;
u32 adc_k_b = 0;
k = (INPUT_VOLTAGE_2 - INPUT_VOLTAGE_1)*8192*1.2/(reg2-reg1);
b = (INPUT_VOLTAGE_1 - (reg1 - 8192)*(INPUT_VOLTAGE_2 - INPUT_VOLTAGE_1)/(reg2 - reg1));
refer_k = k*10000;
offset_b = b*10000;
( refer_k<20000 || refer_k>25000 )?( refer_k=22500 ):( refer_k=refer_k );
( offset_b<14000 || offset_b>18000 )?( offset_b=15840 ):( offset_b=offset_b );
adc_k_b = (refer_k<<16);
adc_k_b = adc_k_b+offset_b;
ft_param_set(CMD_ADC_K_B, &adc_k_b, 4);
adc_k_b = 0;
ft_param_get(CMD_ADC_K_B, &adc_k_b, 4);
uart0PutsCom("adc_k_b:");
printint(adc_k_b);
uart0PutsCom("\r\n");
uart0PutsCom("adc write done\r\n");
}
若有过往能者,还望指点迷津。