iap static method
Implementation
static Uint8List iap(int type,int subtype, int sn , Uint8List data ){
assert(data.length <= 16);
var todata = Uint8List(20);
todata[0] = type;
todata[1] = (subtype & 0x0f) + ((data.length-1) << 4) ;
todata[2] = sn;
for (int i=0; i<data.length;i++) {
todata[3+i] = data[i];
}
crc8(todata);
return todata;
}