Are you getting excited, desperate to try out the new toy?

We are almost finished with the prototype controller but without the program its not going to do a lot, in fact it’s not going to do anything.

Before you upload the program you need to install a library to control the LCD display, this rather excellent piece of work has been created for you by Dale Wentz and you can find out more in the Arduino Playground

There is a tiny bug in the library code which has not as yet been updated, so to save explaining how to fix it I have included the fixed library along with my program.

First thing you need to do is grab the Camera Controller Program and save it to your desktop or other easy to find place.

Inside the zip file you will find 2 folders, CamConV2 is the actual program for the controller, which needs to be copied to your Arduino sketches folder – In windows the default directory is My Documents/arduino/ Unfortunately I have no idea about Macs and Linux because I have never used one, but wherever the default sketches folder is on your system that’s where to copy the CamConV2 folder and its contents

The other folder is LCDi2cR and contains the LCD library code, this folder and its contents should be copied into the libraries folder in the default Arduino sketches folder. If the libraries folder is not there just create it first.

OK, the moment of truth is upon us, time to program the controller.

Start up the Arduino software and select File – Sketchbook – CamConV2. You should be presented with the program in a new window. I am assuming you have the Arduino plugged into the USB port on the computer and everything is ready to go, I did tell you previously that you should install the software and successfully upload the blink demo to the Arduino.

Now select File – Upload to IO Board, the lights on the Arduino should have a fit, and then you should get a message appear on the LCD, then the main menu. If you don’t get any error messages on your computer screen and don’t get a menu displayed on your LCD display it would be a good idea to pull the plug on the controller and check your connections again

If you do end up with a menu appearing on your LCD then things are indeed looking good, if you have made a sensor or two things are looking even better. I guess an attempt at describing how this thing works is now in order.

First of all the controls, you either have a keypad or 5 buttons hooked up, either way there are only 5 ‘keys’ used.

• Keys 1 – 4 select the various options displayed on the screen.
  • Key 2 is also the ‘UP’ key when entering numbers
  • Key 3 is also the ‘DOWN’ key when entering numbers
• Key 5 is the enter key (on the keypad its key 5 get it?)
  • Also ‘EXIT or QUIT’  key when indicated on the LCD
  • Also ‘NEXT PAGE’  key when navigating menus
  • Also moves to next number entry field when entering multiple numbers (times)

When the unit first powers up you are presented with the main menu, this has 2 pages and includes the following items (menu pages will wrap round to the first page):

• Page 1
  • 1 Sensor – Runs the 1 sensor mode
  • Cross Beam – Runs the cross beam mode
  • Directional – Runs the directional dual sensor mode
  • Interval Timer – Starts the interval timer
• Page 2
  • Manual Shoot – Allows you to manually trigger the outputs via a key press
  • Shutter lag – Measures your cameras shutter lag
  • Settings – Enter the settings menu

Each of the different modes have different requirements for sensors etc, obviously 1 Sensor mode only needs sensor 1 configuring. Cross beam and Directional will need 2 sensors configuring. Interval timer and Manual Shoot don’t need any sensors and measure shutter lag needs sensor 1 configuring.

The Shutter lag option works by firing your camera and measuring the time to the flash firing, its probably not fantastically accurate but may help when determining delays etc. To use it you need an optical sensor such as laser trip wire in sensor 1 input, configure the sensor to trigger if higher, set the value as low as you can go (use option 4 to check the ambient) Then connect up the camera (or set it up for infra red control), manual focus, flash on (preferably manual lowest power), aim the flash directly at the sensor from about a meter away and hit 1 to measure.

To configure the sensors (and other settings) you enter the settings menu which has the following items:

• Page 1
  • Sensor 1
    • Trig if higher / Lower
      • Determines whether the sensor value has to be higher or lower than the trigger value. The current setting is enclosed in [ ] brackets
    • Value
      • This is the trigger value, should be set close(ish) to the non triggering value
    • View realtime
      • Displays the lowest, current and highest sensor values detected, use this to determine what value needs to be set above, or to ensure sensor/ reflector are lined up correctly etc
  • Sensor 2
    • Same as sensor 1
  • Output 1
    • Delay
      • This is the delay between the sensor detecting something and the output firing. For example when photographing water splashes you would enter a delay here that gives the drop time to hit the water and splash back up before taking the photo.
    • Time
      • This is the duration of the output in hours, minutes, seconds and milliseconds with a maximum time of 12 hours. You can use this to take long exposure shots with camera in bulb mode, or you could set your camera to continuous shooting mode and take several rapid shots.
  • Output 2
    • Same as output 1
• Page 2
  • Number of frames
    • The number of frames to be shot, you can exit before by using ENTER/ EXIT key
  • Direction time
    • The maximum time allowed between sensor 1 detecting and sensor 2 detecting. The direction mode works by waiting for a trigger on sensor 1 and then checking sensor 2 for a trigger, if sensor 2 is triggered within the set time then the outputs are fired otherwise it goes back to waiting on sensor 1. This allows you to set up 2 laser trip wires parallel to each other some distance apart, the camera will take a picture when sensor 2 triggers but only if sensor 1 was tripped first and therefore the object is moving in the direction of sensor 2 from sensor 1.
  • Interval time
    • The time between frames and is active in all the modes except manual, so if you set this to 1 minute even sensor modes will not take more than a maximum of 1 frame per minute. The interval time is in hh:mm:ss:ms format up to 12 hours all but 1 ms.
  • Offset Delay
    • This delay (0-1000ms) is added to the output delay for each frame. It will allow you to create animations of things like water splashes by taking successive frames at a slightly later time each frame.
• Page 3
  • Output 1 mode
    • Sets the way output 1 works with the current option enclosed in [ ] brackets
      • Wired – using a wired lead to fire camera (or flash)
      • Infra red – Using Nikon IR remote emulation
  • Backlight
    • Lets you set the backlight mode with current option enclosed in [ ] brackets.
      • Off – No backlight used
      • On – Backlight is permanently on
      • Timed (5-60s) comes on for the set time when any key is pressed then goes out.
  • Main Menu
    • Returns to the main menu.

There are a couple of things to be aware of:

When using Infra Red control mode you cannot use bulb mode on the camera, you should set the camera to a manual or auto exposure otherwise the camera will open the shutter and not close it again. So at the moment at least you cannot do long exposures with IR

Both outputs are fired every trigger event, although not necessarily at the same time nor for the same duration. You can use a camera or flash on either or both outputs so you could for instance use 2 cameras take stereo photos or 2 flashes to create double exposures with very small time differences etc

If your flash has a strobe effect (Nikon SB800/ SB900 etc) you can set the output to a longer duration to take strobe effect photos.

If an output with a flash has too short an Output Time the flash may not fire, use trial and error to find the minimum duration needed for your flash.

Cameras should preferably be set to manual focus, the controller has no means of detecting if auto focus has finished so for autofocus use you will need to increase the Output Time to allow the camera enough time to focus. Given that the controller is geared toward detecting an object at a specific place I don’t think autofocus is really an issue.

Some flash guns can have very high voltages on their PC sync/ hot shoe connectors and if so could fry the 4N35 opto coupler, if this is an issue contact me and I will try to sort out a more robust output isolator for you.

Next version of the software will hopefully save all the settings to Flash memory to cut down the workload setting it up each time

Finally, I am by no means a expert programmer as you will probably be able to tell from the spaghetti code, if you are (or at least better than me) and have any suggestions for improving the code PLEASE do let me know.

Well that’s about it for now, next part I will cover connecting cameras and flash guns to the outputs so you can really start to use the thing in anger.

Part Seven – Outputs is coming soon, watch this space..

Tags: Arduino, DIY, Electronics, Photography

This entry was posted on Wednesday, November 11th, 2009 at 8:48 am and is filed under Photography Tutorial. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.