One of the requirements of the sensor helmet will be to confine the action camera. The 808-16 camera that I’m currently using sits on top of the helmet with a USB cable tethered from it to a LiPoly pack on the back of the helmet. My first helmet had this USB cable on the outside of the shell. The second and third generation helmets had the cable routed inside, but the camera and battery pack were still on the outside.
I would like to do away with putting items on the outside of the helmet as much as possible. I lucked out one evening when I stumbled upon Techmoan’s video blog about the 808 series of action cameras. He’s got a clear and articulate manner and it really broke it down for me. He mentioned that more details are available from the Tom Frank’s RC Forum and Chuck Lohr.
With all these resources about the 808 series cameras available and my personal experience using them for the past 3 years, I figure they are worth using on this project. The lens assembly can be detached on the #16 and #26 series 808 cameras using a cable extender.
I also looked at the possibility of extending the microphone and decided to try this out on one of my 480p 808 camera. This camera has been shelved due to its short record time, low resolution, and unpredictable operation. The worse thing that could happen is I brick it.
So I opened it up and figured I could run the battery terminal and microphone positive terminal to a BLS female header. After some continuity testing, soldering, crimping, and more continuity testing I was ready to assemble it.
I cut out a slot on the bottom casing and hot glued the BLS header to the case. Then I closed up the case and sealed up seams that didn’t latch with some more hot glue. Once that was cooled, I went ahead and positioned one of my iPhone zoom lens backings to the case and centered it over the lens opening. With that all set, I popped the wide angle lens on then hot glued it to the case.
All done, now I can run an external 5Vdc source to the camera and hookup an external mic. I managed to salvage the microphone from the camera and soldered leads on it. While working on the mic, I was testing the power to the camera. The video ran without issues, but I noticed some noise on the sound. I figured it was noise on the line and could be filtered out with a cap between the VCC and GRN pins. Then I got a hair brained idea about connecting the mic pin on the camera to one of the PWM pins on the Arduino. Here’s how it went…
I’m not sure if the mic is faulty or I just cooked the op amp on the camera. But one this is for sure, this will be a useful auxillery camera. I’ll try and use restraint in the future when getting wild imaginative ideas. I could test the mic with a known good op amp, but I don’t think this is a big deal and might visit it another time.