请教一个KEIL编译问题

Question

定义：unsigned int Value_VAIN3;

unsigned char read_ad(unsigned char add)
{
unsigned char dat;
IIC_Start();
IIC_SendByte(0x90);
IIC_WaitAck();
IIC_SendByte(add);
IIC_WaitAck();

IIC_Start();
IIC_SendByte(0x91);
IIC_WaitAck();
dat=IIC_RecByte();
IIC_Ack(1);
IIC_Stop();
return dat;

}
问题代码 Value_VAIN3=read_ad(0x03)500/255; //0-255转换为0-500
报错：main.c(326): error C193: '': illegal type conversion from/to 'void'

Answer 1

改成这样 Value_VAIN3=read_ad(0x03)*500/255;