Experiment to see if various low cost ATMega processors on Arduinos were fast enough to trigger some scientific equipment. Next step would be ASM. Measured with an oscilloscope

Impulse.Generator.ino

const int TRIGGER_PIN = 8;

const double HIGH_TIME = .012; 
const int LOW_TIME = 10;
const int PULSE_DELAY = 98;
const int GROUP_DELAY = 920;

void setup() {                
  TRIGGER_PINMode(TRIGGER_PIN, OUTPUT);
}

// Written sequentially to avoid
// any wasted cycles on control flow

// delay(millisec)
// delayMicroseconds(microsec)

void loop() {

  //Packet 1
  digitalWrite(TRIGGER_PIN, 1);
  delayMicroseconds(HIGH_TIME);
  digitalWrite(TRIGGER_PIN, 0);
  delay(LOW_TIME);
  digitalWrite(TRIGGER_PIN, 1);
  delayMicroseconds(HIGH_TIME);
  digitalWrite(TRIGGER_PIN, 0);
  delay(LOW_TIME);
  digitalWrite(TRIGGER_PIN, 1);
  delayMicroseconds(HIGH_TIME);
  digitalWrite(TRIGGER_PIN, 0);
  delay(LOW_TIME);
  digitalWrite(TRIGGER_PIN, 1);
  delayMicroseconds(HIGH_TIME);
  digitalWrite(TRIGGER_PIN, 0);
  
  delay(PULSE_DELAY);
  
  //Packet 2
  digitalWrite(TRIGGER_PIN, 1);
  delayMicroseconds(HIGH_TIME);
  digitalWrite(TRIGGER_PIN, 0);
  delay(LOW_TIME);
  digitalWrite(TRIGGER_PIN, 1);
  delayMicroseconds(HIGH_TIME);
  digitalWrite(TRIGGER_PIN, 0);
  delay(LOW_TIME);
  digitalWrite(TRIGGER_PIN, 1);
  delayMicroseconds(HIGH_TIME);
  digitalWrite(TRIGGER_PIN, 0);
  delay(LOW_TIME);
  digitalWrite(TRIGGER_PIN, 1);
  delayMicroseconds(HIGH_TIME);
  digitalWrite(TRIGGER_PIN, 0);
  
  delay(PULSE_DELAY);
  
  //Packet 3
  digitalWrite(TRIGGER_PIN, 1);
  delayMicroseconds(HIGH_TIME);
  digitalWrite(TRIGGER_PIN, 0);
  delay(LOW_TIME);
  digitalWrite(TRIGGER_PIN, 1);
  delayMicroseconds(HIGH_TIME);
  digitalWrite(TRIGGER_PIN, 0);
  delay(LOW_TIME);
  digitalWrite(TRIGGER_PIN, 1);
  delayMicroseconds(HIGH_TIME);
  digitalWrite(TRIGGER_PIN, 0);
  delay(LOW_TIME);
  digitalWrite(TRIGGER_PIN, 1);
  delayMicroseconds(HIGH_TIME);
  digitalWrite(TRIGGER_PIN, 0);
  
  delay(PULSE_DELAY);
  
  //Packet 4
  digitalWrite(TRIGGER_PIN, 1);
  delayMicroseconds(HIGH_TIME);
  digitalWrite(TRIGGER_PIN, 0);
  delay(LOW_TIME);
  digitalWrite(TRIGGER_PIN, 1);
  delayMicroseconds(HIGH_TIME);
  digitalWrite(TRIGGER_PIN, 0);
  delay(LOW_TIME);
  digitalWrite(TRIGGER_PIN, 1);
  delayMicroseconds(HIGH_TIME);
  digitalWrite(TRIGGER_PIN, 0);
  delay(LOW_TIME);
  digitalWrite(TRIGGER_PIN, 1);
  delayMicroseconds(HIGH_TIME);
  digitalWrite(TRIGGER_PIN, 0);
  
  delay(GROUP_DELAY);
  
}