例如下面这段生成正弦波的代码：
unsigned char sin_tab [256] = {127,130,133,136,139,142,145,148,151,154,157,160,164,166,169,172,175,178,181,184,187,189,192,195,197,200,202,205,207,210,212,214,217,219,221,223,225,227,229,231,232,234,236,237,239,240,242,243,244,245,246,247,248,249, 250,251,251,252,252,253,253,253,253,253,254,253,253,253,253,252,252,251,251,250,249,249,248,247,246,245,243,242,241,239,238,236,235,233,231,230, 228,226,224,222,220,218,215,213,211,209,206,204,201,199,196,193,191,188,185,182,180,177,174,171,168,165,162,159,156,153,150,147,144,141,137,134,131,128,125,122,119,116,112,109,106,103,100,97,94,91,88,85,82,79,76,73,71,68,65,62,60,57,54,52,49,47,44,42,40,38,35,33,31,29,27,25,23,22,20,18,17,15,14,12,11,10,8,7,6,5,4,4,3,2,2,1,1,0,0,0,0,0,0,0,0,0,0,1,1,2,2,3,4,5,6,7,8,9,10,11,13,14,16,17,19,21,22,24,26,28,30,32,34,36,39,41,43,46,48,51,53,56,58,61,64,66,69,72,75,78,81,84,87,89,93,96,99,102,105,108,111,114,117,120,123,127};
void setup()
{
DDRD =0xFF;
}
void loop()
{
for (int i=0;i<256;i++)
PORTD=sin_tab[i]
}
其中，unsigned char sin_tab [256] 的数组元素是如何得来的？可不可以用某个外部设备来动态的生成？应该肯定是可以的。那么需要什么样的元件和电路呢？
我想做一个可以实时控制波形的电路。
unsigned char sin_tab [256] = {127,130,133,136,139,142,145,148,151,154,157,160,164,166,169,172,175,178,181,184,187,189,192,195,197,200,202,205,207,210,212,214,217,219,221,223,225,227,229,231,232,234,236,237,239,240,242,243,244,245,246,247,248,249, 250,251,251,252,252,253,253,253,253,253,254,253,253,253,253,252,252,251,251,250,249,249,248,247,246,245,243,242,241,239,238,236,235,233,231,230, 228,226,224,222,220,218,215,213,211,209,206,204,201,199,196,193,191,188,185,182,180,177,174,171,168,165,162,159,156,153,150,147,144,141,137,134,131,128,125,122,119,116,112,109,106,103,100,97,94,91,88,85,82,79,76,73,71,68,65,62,60,57,54,52,49,47,44,42,40,38,35,33,31,29,27,25,23,22,20,18,17,15,14,12,11,10,8,7,6,5,4,4,3,2,2,1,1,0,0,0,0,0,0,0,0,0,0,1,1,2,2,3,4,5,6,7,8,9,10,11,13,14,16,17,19,21,22,24,26,28,30,32,34,36,39,41,43,46,48,51,53,56,58,61,64,66,69,72,75,78,81,84,87,89,93,96,99,102,105,108,111,114,117,120,123,127};
void setup()
{
DDRD =0xFF;
}
void loop()
{
for (int i=0;i<256;i++)
PORTD=sin_tab[i]
}
其中，unsigned char sin_tab [256] 的数组元素是如何得来的？可不可以用某个外部设备来动态的生成？应该肯定是可以的。那么需要什么样的元件和电路呢？
我想做一个可以实时控制波形的电路。
