// https://cdn.sparkfun.com/assets/2/8/b/a/a/Tiny_QuickRef_v2_2.pdf

int servoChan[] = {PB0, PB1}; // one pin per servo
int pot = PB2; // potentiometer
#define angle0  450 // specific to this servo at 0 degrees
#define angle180 2450 //specific to this servo at 180 degrees
#define delayLO 250
#define delayHI 1000

void setup() {
  pinMode(servoChan[0], OUTPUT);
  pinMode(servoChan[1], OUTPUT);
  pinMode(pot, INPUT);
}

void loop() {
  gotoZRO(servoChan[0]);
  goto180(servoChan[1]);
  goto180(servoChan[0]);
  gotoZRO(servoChan[1]);
}

void gotoZRO(int servo) {
  digitalWrite(servo, HIGH);
  delayMicroseconds(angle0);
  digitalWrite(servo, LOW);
  delayMicroseconds(20000 - angle0);
  delay(map(analogRead(A1), 0, 1023, delayLO, delayHI));
}

void goto180(int servo) {
  digitalWrite(servo, HIGH);
  delayMicroseconds(angle180);
  digitalWrite(servo, LOW);
  delayMicroseconds(20000 - angle180);
  delay(map(analogRead(A1), 0, 1023, delayLO, delayHI));
}