arduino code from thursday

Virtual Cameras No Comments »

/*
* Button
* by DojoDave
*
* Turns on and off a light emitting diode(LED) connected to digital
* pin 13, when pressing a pushbutton attached to pin 7.
*
* http://www.arduino.cc/en/Tutorial/Button
*/

//int ledPin = 11; // choose the pin for the LED
//int ledPin2 = 3; // choose the pin for the LED
int cameraPin = 11;
int inputPin = 4; // choose the input pin (for a pushbutton)
int val = 0; // variable for reading the pin status
int once =1;

void setup() {
pinMode(cameraPin, OUTPUT); // declare LED as output
// pinMode(ledPin2, OUTPUT); // declare LED as output
pinMode(inputPin, INPUT); // declare pushbutton as input
}

void loop(){
val = digitalRead(inputPin); // read input value

if (val == HIGH) { // check if the input is HIGH
// if (once == 1 ) {
// once = 0;
// digitalWrite(ledPin2, HIGH); // turn LED ON
digitalWrite(cameraPin, HIGH); // turn LED ON
delay(1700);
digitalWrite(cameraPin, LOW);
delay(1500);
} else {
digitalWrite(cameraPin, LOW); // turn LED ON
// digitalWrite(ledPin2, LOW); // turn LED ON
}
}

test post

Virtual Cameras No Comments »

test post!

The camera as a generalized optical receiver and transmitter.

Uncategorized No Comments »

Ramesh Raskar defines a camera as “a box with parameters” and suggests that the first computational photography “movement”, epsilon photography, is simply extending each of these parameters. From this kind of photography it is possible to extend dynamic range, extend depth of field, extend low-light noise performance, and so on.
However, the camera is more than just a box with operating parameters. The camera can actually be conceived of as an optical receiver/transmitter pair. A generalized camera concept would represent the camera not as a box with parametric capabilities but rather a collection of small devices working together to form a whole. The exact nature of these devices changes per device, but generally fall into a few categories.

Category 1. Optical receivers.

This category includes the imaging sensor, autofocus sensor(s), white balance sensor, secondary imaging sensor for EVF cameras, etc. Including the user’s retina also makes the viewfinder an optical receiver.

Category 2. Optical transmitters.

This category includes the flash, autofocus LED, LCD display, and all other LEDs on camera.

Category 3. Audio receivers.

Typically, this is a monaural microphone sampling at a high sample rate (at least 22khz). Occasionally these are stereo.

Category 4. Audio transmitters.

Typically, this is a small piezo buzzer and/or a small speaker, being run from the same DAC and at the same sample rate as the monaural mic.

Rather than thinking about the specific parameters of these devices, it should be possible to reconceive them as a sort of lego construction set. Need a bright image projected into the scene? hook the flash up to the viewfinder. Etc.

11/3/09 Notes/Reetz

Uncategorized No Comments »

Abstract:

A series of simple modifications/add on hardware to current DSCs that allow them to bidirectionally communicate optically and become active agents in photography.

Examples:

Tourist: You must interrupt a stranger and ask them to take a picture

If you’re with a group one member must be absent from the picture

Solves the “where’s waldo problem” of crowd photos

Solves problems about having camera in the right position, time, direction

Partially solves photo-finding problem.

Allows for potentially unposed or less-posed shots and action shots.

Camera phone on the belt solves the carry problem; also note/illustrate other carry locations.

Lots of discussion about identifying pictures by location

Re-conceiving the camera with LCD /flash as an optical transmitter/receiver pair.

Hashing image contents/talk about the many ways pictures could be geo-located

Camera as potential beacon

Outline 11/03/09

Uncategorized No Comments »

Notes; in no particular/ chronological order:

? write an app for a phone that can read “requests” and snap the photo

1 of 10 may have GPS
1 of 100 may be able to read bokodes

time signature can be _very_ accurate
Remote trigger may log time for easy searching
phones have network time
can correlate to other photos

Dongle

  • Sync once (like paypal key)
  • 1 sec or so granularity
  • allows with a “one-way” function to tell time cheaply

_System for transmitting metadata between distinct devices_

Long+short exposures -> user waves phone/dongle in the air
-> morse-code led code on long exposure image

Immediate tasks
1) Make a single device request a single photo

  • Sony IR remote protocol

2) Space encoding

  • bokodes

3) Time encoding

  • (cellphones)

4) sound

  • e.g. proximity to a live show
  • gradient of amplitude as user is farther away

5) Pole/beacon

  • transmits location, time, etc. metadata
  • (standardized format, etc.)

6) bokode in viewfinder?

  • projection onto scene

_System for automatic metadata addition_

leader beacons -> followers sync metadata

Old notes (10/22/09?) from the server

Uncategorized No Comments »

ubiquitous photography
camera credit/karma (kamera karma?)
Home/campus security
Night club

Levels of promiscuity
_1st no permission_

  • hacker trigger – knows all (ir codes) to signal picture taking
  • next – custme hardware (chdk)

_permissive/opt-in_

  • addition of hard/software to camera
  • allow selective use

_whore camera_

  • triggered by anything

Smart enough tagging -> crowd-sourced news
ex. Georgia/Russia missile dispute; one user w/ good photo = 1-3 million hits +++karma

Want wireless offloading of the data? 3G networks.

Important concept: discuss many implementations -> show how they all cooperate with the system

Implementations
usb-dongle w/ chdk
usb-dongle for cellphone
mask over flash for IDing
ir receiver on camera
flash sync

Tuesday the 27th Meeting Notes

Uncategorized No Comments »

Siggraph Paper rejection guidelines:

http://www.siggraph.org/publications/instructions/rejected

Siggraph paper deadline: Jan 19th

Outstanding question: Talk, paper, poster?

Possible conferences

Siggraph

IEEE

Ubicomp

ACM CHI

JOSA

http://chdk.setepontos.com/index.php/topic,4338.0.html

http://www.mweerden.net/chdk_ptp.html

Tasks:

Read MERL paper and generate outline. Deadline: Next tuesday.

for reading later

http://projects.dimension-x.net/technology-and-projects/ledsensors

http://cgi.ebay.com/SEAGULL-SYK-3-Hot-Shoe-Flash-Light-Remote-slave-Trigger_W0QQitemZ250482346462QQcmdZViewItemQQptZCamera_Flash_Accessories?hash=item3a51e949de

http://cgi.ebay.com/Remote-Control-for-Pentax-Camera-K110D-K100D-K10D-istDL_W0QQitemZ220340209004QQcmdZViewItemQQptZCamera_Camcorder_Remotes?hash=item334d4cc56c

Interesting lectures from Stanford.

Online Class 1 Comment »

Compressed sensing:

Sensing technologies for future form factors:

Fourier Transforms playlist:
http://www.youtube.com/view_play_list?p=B24BC7956EE040CD&playnext=1

Lecture 1 | The Fourier Transforms and its Applications

Online Class 1 Comment »

Notes for lecture 1.

Procedures:
Analysis is breaking a signal down into its component parts.
Synthesis is reconstructing a signal from component parts

Both analysis and synthesis are accomplished with linear operations. (Integrals and series).

Periodic phenomena and Fourier Series:
This is the mathematics and engineering of regularly repeating patterns. Periodicity is Spatial, Temporal, or both.

Periodicity of a physical phenomenon is a consequence of symmetry. Periodicity arises from spatial symmetry. The period is the length of the pattern before it repeats.

Temporal periodicity is most often described with frequency (number of repetitions per unit time).

Temporal and spatial periodicity come together in phenomena like wave motion/ a regularly moving disturbance.

The relationship between frequency and wavelength is:
Distance = Rate * Time.

If the rate is the velocity of the wave, then
V=velocity (rate)
L= V*1/u (lambda equals velocity times 1 over nu, nu is unit time)
Lu=V

This formula describes a reciprocal relationship between frequency and wavelength.

Simple, periodic mathematical functions can be used to model periodic phenomena. SIN and COS.

COS(t) and SIN (t) are periodic of period (2pi)
that is
Cos(t+2pi)=cos(t)
Sin(t+2pi)=sin(t)

The simplest object that regularly repeats is a circle. More sophisticated than SOH CAH TOA, which is incomplete. Get to know the Unit Circle. SIN and COS are associated with periodicity in space.

Not just 2pi, but any multiple of 2pi
COS(t+2pin)=cos(t) — determines clockwise or counterclockwise motion on the unit circle

Arduino-based Camera Trolley

Arduino, Virtual Cameras 1 Comment »

trolley_rev_6

I made a camera trolley using:

1. Some guts from a Fuji high-speed scanner
2. An Arduino
3. An SN75441ONE Dual H-Bridge driver
4. A power supply ganked from some old equipment.
5. A bunch of scrap plastics and metals.
At the moment, the software is primitive, but functional. I started out with Tom Igoe’s stepper driver example, and the stepper circuit listed on the Arduino reference (which is also on Tom’s page).

My major design goal is to automatically, predictably, and repeatedly move a camera left to right in increments and take a picture at each increment. I am about 50% there. I have a trolley which moves predictably and repeatedly right-to-left, which is good.
For this to be really useful, I need to:

1. Make the thing seek “home” to an optical sensor and start from that point every time.
2. Put a 1/4 20 bolt on the carriage to secure a camera.
3. Make the code more graceful (use division and variables instead of hardcoding stuff)
4. Connect the shutter release to the Arduino.

The last thing is interesting because it will be different for each camera. I have purchased a remote for my Powershot S70 on eBay, hoping that I can use that to fire the shutter without opening the camera. However, if this complicates my setup, I will just rip open the camera and wire directly to the shutter contacts or perhaps install a jack. Since that will likely eat up an afternoon, I won’t do it unless it is absolutely necessary.

Video: