After seeing a Picaxe based unit on the internet I saw now reason why I could not build one of these units my self. after quite a lot of testing and waiting for parts to arrive I eventually came to a design that seems to work extremely well
the circuit:
Proto-0.3 by f2268d215cc925918731918f4efa0289, on Flickr
I ended up using the on-chip comparators to fire an interrupt. The system is able to control both the shutter of the camera and the flash via a modified sync cable. Due to the fact that this kind of photography normally happens in a dark room being able to see what you are doing was an important factor that needed to be addressed. This was done by using a torch with a broken switch and modifying it to receive power from the system, this means when "Run" is pressed it switches the torch off, opens the shutter and waits for the signal from the sensor.
The comparators make use of the IVR, this allow the user to easily make changes to the point at which the signal changes the state of the interrupt flag - essentially meaning they can change the sensitivity of the inputs.
The primary sensor at the minute is the sound detector provided rev Ed http://www.picaxe.com/docs/picaxe_sound.pdf
there where many test shots normally involving a hammer and something being smashed - I found that walnuts are very tasty. after the initial testing found the that everything was working well I moved to something a little more interesting
Water-ballon-0 by f2268d215cc925918731918f4efa0289, on Flickr
Water-balloon-1.2 by f2268d215cc925918731918f4efa0289, on Flickr
this shot had an added 1.2ms delay
I should have used a greater f-stop but I am still learning this new technique.
The final setup allow for adding a delay between the signal and the output, the ability to strobe the flash and to make use of multiple camera settings including burst, single, mirror up and bulb mode
the circuit:
Proto-0.3 by f2268d215cc925918731918f4efa0289, on Flickr
I ended up using the on-chip comparators to fire an interrupt. The system is able to control both the shutter of the camera and the flash via a modified sync cable. Due to the fact that this kind of photography normally happens in a dark room being able to see what you are doing was an important factor that needed to be addressed. This was done by using a torch with a broken switch and modifying it to receive power from the system, this means when "Run" is pressed it switches the torch off, opens the shutter and waits for the signal from the sensor.
The comparators make use of the IVR, this allow the user to easily make changes to the point at which the signal changes the state of the interrupt flag - essentially meaning they can change the sensitivity of the inputs.
The primary sensor at the minute is the sound detector provided rev Ed http://www.picaxe.com/docs/picaxe_sound.pdf
there where many test shots normally involving a hammer and something being smashed - I found that walnuts are very tasty. after the initial testing found the that everything was working well I moved to something a little more interesting
Water-ballon-0 by f2268d215cc925918731918f4efa0289, on Flickr
Water-balloon-1.2 by f2268d215cc925918731918f4efa0289, on Flickr
this shot had an added 1.2ms delay
I should have used a greater f-stop but I am still learning this new technique.
The final setup allow for adding a delay between the signal and the output, the ability to strobe the flash and to make use of multiple camera settings including burst, single, mirror up and bulb mode