Thanks for the heads up!
I updated currentMillis
void wheelservo()
{
unsigned long periodcontservo = 2000;
static unsigned long lasttime = 0;
int line = analogRead(linesensor_value);
if (line > 790) {
unsigned long currentMillis = millis(); // begin to get current time
while (currentMillis - lasttime < periodcontservo) {
continuousservo.writeMicroseconds(1480);
lasttime = currentMillis;
}
}
else {
continuousservo.writeMicroseconds(1430);
}
}
Now the continuous servo spins until desired value then spins slowly in the same direction without ever stopping.