Well, I promised you the story about the fireCrow project.
Fasten your seat belts 'cause here it goes! 🙂

In the beginning there were only 2 channels...

It all started with an idea about making a small and secure 2 channel wireless firing system primary used for squibs (sfx body hits). I didn't thought that there was anything like that on the market, all I knew about was a single channel, made in China system that was quite expensive, lack of security and didn't have a nice form factor (if you aske me).

So i simply started to investigate how to make my own system, what kind of hardware to use and how to put it together, since I didn't have any knowledge about electronics to start with it was like a jungle for me.
Simultaneously my friend David started to play around with this amazing microcontroller called Arduino, he heard about it on a "talk" at FSCONS I belive.
Things took an exciting turn when I early in February 2009 I mentioned my idea to David.
The flame was lit!

From the beginning there was a lot like learning to write code, much copy and paste! 😉
I looked at schematics on Arduinos, floating led light circuits and many more, to figure out how to do things the right way. Of course there was a lot of asking around at forums, mostly Svenska Elektronikforumet (Swedish forum for electronics), thanks guys, you helped a lot!!!

After some research we stumbled over the XBee. Seemed like it was quite commonly used with Arduinos and other wireless project that needed the same level of security as we did.
We decided to skip the microcontroller on the receiver because the XBee had its own I/O ports that we thought we could use, the transmitter on the other hand we used a ATtiny2313, David found out that it could run an Arduino tiny core which saved a lot of coding and time!

When I did my fisrt schematics it looked quite different to the ones I make today, back then I draw them in paint, now a days I use Eagle!
Here are the oldest schematics I could find (not the first) of the transmitter and receiver
There is an ATtiny2313 added to the receiver (below) so this have to be the second version:

About four months later and much redrawing we had two "working" prototypes with some minor bugs. We called the "system" PyroFyro (something like PyroFiring translated) they looked like this:

In August David became proud father of his son Frode and we had to take a small brake with the project.

I think we picked up the project again in the summer of 2010.
We then discovered there was a problem using the XBee to directly control the relays, if pressing the buttons to fast after each other some kind of buffer overflow made a delay on the firing.
This was one of the minor bugs we had, in generally the two first button press worked fine if not pressed to close, but there was no continuity and therefore not reliable.

After many hours of googling and reading we decided to add a micro-controller to the receiver, we also added external crystals to the micro-controllers to get the serial communication to work correctly.

This is how it looked after the modification

Unfortunately we ran in to some more trouble with the receiver. Somehow one of the channels got f**ked up after adding the micro-controller, a transistor broke I think, and of course the backside was covered with silicone so it was a pain in the ass to fix if even possible at all 🙁

The worst thing about this was that I where supposed to use the PyroFyro to shoot Daniel, my brother in law, as a birthday present later on!
So, I had to improvise by making a relay shield to fit on an Arduino FIO. It worked out quite well except that when we should do the shooting the battery somehow got fried so we couldn't use it anyway! 😀
Luckily my friend Lennart helped out so Daniel finally could get "killed" !

The dude with the protecting glasses is me taking of the "victim" his bloody gears.
If you look closely you could see the clumsy receiver in his back pocket.

From here on the project took other turns!
I've started to do the schematics and PCB design in Eagle and we had plans for a new MCU and we'd decided to turn it into an open hardware multi-platform microcontroller.
So this was the end for the 2 channel PyroFyro system that started it all, but never the less the beginning and rise of the fireCrow! 😎