Morse code over laser light with an Arduino

19. After another of my famously lavish parties, I sometimes walk alone out to Promontory Point at exactly 10:00 p.m. Thursday and glance lakeward, out at a blinking light on some distant shore, and think of Daisy Buchanan. That light winks on and off, unattainable, a powerful metaphor for|wait, is that Morse code? [5 points for lights over a mile away; 15 points for lights over 5 miles away; 0 points for lights that are only metaphors] For this Scav Hunt item I used an Arduino to turn a laser pointer on and off in morse code:

#define pulseHigh(pin) {digitalWrite(pin, HIGH); digitalWrite(pin, LOW); }
#define RESET 13  // Pin 13 

void setup() {
pinMode(13, OUTPUT);
}

void loop() {
      
      digitalWrite(13,HIGH);
      delay (3000); 
      digitalWrite(13,LOW);
      delay (1500);
      dash();dash();dot();space();
      dot();dash();space();
      dot();dot();dot();space();
      dot();dot();dot();dot();space();
      delay(2000);
      
      
      pulseHigh(RESET); // off
};


void dot()
{
  digitalWrite(13,HIGH);
  delay(100);
  digitalWrite(13,LOW);
  delay(100);
  
}

void dash()
{
  digitalWrite(13,HIGH);
  delay(300);
  digitalWrite(13,LOW);
  delay(100);
  
}

void space()
{
  digitalWrite(13,LOW);
  delay(300);
}

I checked and saw at http://www.heywhatsthat.com/?view=PKDC86DD that the path from Adler Planetarium to the Point was just a touch over five miles and free. I could identify the Point fairly well in binoculars; I aimed the laser pointer by fixing to a tripod, testing the aiming by hitting nearer objects (a beach buoy nearby happened to be retroreflective which helped quite a bit) and then carefully moving the system towards the Point. I turned it off whenever boats went near the beam. To prove it was me, the judge requested I manually hit the key a few times--since I had only a programmed 'SCAV' (yes, it says GASH above), I manually connected the pointer to 5V & ground on the Arduino. It was powered via a 12V battery and a cigarette lighter USB charger to provide 5.1V.

Raft part 2

They finally got underway again, after a stop at the Riverdale Marina. They ended up replacing their outboard with a newer and slightly more powerful model. This then tripped them up as it tried to tear away from the raft. Suitability reinforced, they left this morning down the Cal-Sag to parts south.

This image is really the best, caught by Dave D., a boater who had seen them earlier while at the Riverdale Marina, he just happened to see them while crossing the 127th St. bridge, and he then headed further west to the Ridgeland Ave. bridge and caught some great shots.



Update: I just got a call from Igor; they've docked for the night near the last SEPA station right at the junction of the Cal-Sag and the Chicago Ship and Sanitary Canal, just a touch past the Illinois and Michigan Canal remnants and will be walking a mile up and across the river to the nearest gas station to pick up some gas.

Raft

My time has been taken up with four friends of mine who are building a raft. Building a raft to travel from Chicago to New Orleans. I've been helping out as my schedule allows, although I took a few days off recently to help out on moving the preassembled parts from the backyard of a Hyde Park apartment to the Croissant Marina on the Little Calumet River. (This marina is a great spot--amazing for the friendliness, the methane purgers on the other side of the river, and the barges passing silently by). The weather gods have not been kind though. The majority of the water on the Little Calumet is effluent, and this weekend Chicago received the highest one-day precipitation event ever, AND the remnants of Hurricane Ike, in two separate rain events. In the scheme of things, it was so bad they opened all the normally closed locks that keep the Chicago river and canals from flowing into Lake Michigan. So, our previous spot at the marina is now covered in combined sewage and storm output by ten feet. It put a damper on the weekend for a lot of people; a lot of people are flooded out of their basements and apartments. Ryerson Observatory reports almost 11 inches of rain in the past seven days.

While we now have a 16ftx32ft raft, we still need to mount the 35hp motor and construct the cabins and hammock supports for the travelers. Try this link for construction photos. You might be able to see it without a facebook account--I'm just dumping stuff without much editing.