I've got no answers, but I've got a couple questions. Out of curiosity, what micro are you using? Do you have an idea what the current draw is on the board attached to the helmet? I'm thinking battery size vs battery life.
I would think you should be able to get a dev kit with all the I/Os pulled out and create something a little cleaner (for yourself anyways). I'm just picturing you driving down the road with something like this attached to the back of your skull bucket.
The blinker thing is a great idea. I've almost give up using my blinkers since I always forget to cancel them. I'm surprised someone hasn't come up with some sort of auto canceling mechanism. Cant really be that hard...
That pic is what i have and EXACTLY what I'm trying to avoid. I'm using commercial radios that are already FCC-blessed. They provide a standardized network layer that can be accessed by any other device that also uses the same layer provided the encryption isn't used (I'm not). Now that Omaha_919 has mentioned it, I don't want to list details not too many anyways.
In the interest of full disclosure, I should tell everyone that this idea was originally conceived and prototyped by one of the other design teams when I was in school earning my EE. I've harassed some of the team members a couple of times and they aren't going forward with it. They haven't blessed my pursuit of it, so I need to talk to them. That being said, I do not and did not know how they implemented any of the features they offered (theirs was WAY cooler-HUD in the visor with rpm and speed-o readings plus the signaling stuff I mentioned) and am developing this independently. Not sure that any of that matters if they have a problem with it, but right now this is for me. If i decide to share my cool toy, then I will have to figure that out at that time.
Back to the deets: I'm using an off the shelf micro: the arduino uno. It's completely open source, and infinitely easy to get working. There are several variants of this microprocessor and I encourage anyone that is interested to look into this family of micros. arduino.cc will get you started and unfortunately, the deeper you dig, the more you want to buy and play with.
The radios are xbee modules. the ones that will ultimately go into the project will not be the pro version (the ones I'm tinkering with) since 1 mW is PLENTY to get from a bike to a helmet. the 60 mW that the pro version puts out is good for a mile line of sight (ymWILLv).
I'm not concerned with the current draw of the board, since the use of the expensive radios allows me to keep the board on the bike! the radio plus the bits needed to make drive the LEDs will pull <200 mW peak (for now) so a pair of AAAs should be good for a few rides. I'd like to get more sophisticated with the power, but that's a task further down on my requirements list.
for the blinker... I don't know that an audible indication is a good idea after thinking it through. My Shoei rf-1000 seems to roar at highway speeds, so getting anything heard at that speed will require some doing. That isn't the part that worries me. It's listening to that volume with nothing to balance out the noise when you are stopped or are moving slowly that worries me. I'm thinking a visual indication somehow would be better, but then again, would that be too busy? I'll have to try it and see. (If I ever get to the parts store to grab the right value of pull down resistor i might eventually get this thing strapped to my helmet.) Also, if I was feeling froggy, I could prolly rig an auto canceling scheme on the controller since it's bike-mounted. I read that Goldwings have to move more than a set distance and have been on for a set time and they will auto cancel once both conditions are met.
Thanks for all the interest and support (esp you, Bigdaa I've only found one place to prototype boards and they aren't *expensive* but they aren't cheap either.)