Monday, 14 March 2011

Camera flash trigger project - circuit design

So my flash trigger is getting a nice box, and I'm ditching the breadboard in favour of stripboard (old habits picked up in AS level electronics die hard), but I want to keep the box innards as flexible as possible so I can put in new projects. To that end, I'm making the flash circuit separate to the power, input and output boards.

Two big issues with the current system - one, you can't easily align the laser without triggering the flash! This can be fixed by having an 'alignment mode' built in with a pushswitch to toggle between this mode and the flash mode. Another LED in the case will indicate which mode you're in :)

Problem two, you can only change the flash timing by uploading a new program. Not good in the field (netbook notwithstanding). Hence a plan to use the mode switch as a primitive timing selector by press-hold, tap out delay in 10's ms (say) and press-hold to set... The mode LED then flashes out the delay count (in 10's ms again) to confirm. My strategy is that of most modern hardware manfs - build in the bits in the box, then worry about writing software later on and release a patch :-] I'm looking at you Apple...

In the future I might look at using a segment display, but I reckon my 1990's digital watch approach should be workable :D

Oh, also I'm adding another circuit that can trigger my Canon SLR shutter to make the system more flexible. That kinda makes the flash delay bit make more sense I guess :-/

Camera flash trigger project - Boxing up

So my first try at boxing up involved an old network switch box (literally a switch to change between two networks). The metal box was OK for holding the arduino and a breadboard, but a bit rubbish when it came to power (required a USB source) and the wires were selotaped to the case... deffo dodge.

Quick trip to Maplin and I've now got a shiny ABS box for the arduino and circuit, plus a power pack, cable connectors (simple phono types) and a 1/0 switch to turn the whole thing on.

After a bit of drilling, hacking and hot glue, I have the following in-progress box:
Arduino box (top), laser remote (left) and LDR remote (right)
Main box with mounting point for the Arduino (from a motherboard mounting kit ;))

Phono jacks and holes for arduino USB and power