Helmet Camera

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Building A Helmet Camera System For Adventure Racing

Full Helmet Camera Setup
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Full Helmet Camera Setup

So my helmet camera setup continues to draw attention in the adventure races in which we participate, and people keep saying, "I want one." So I figured I'd show how this one was built and provide some resources for folks who want to build their own.

First, I want to say that my goals for this helmet camera were:

  1. Waterproof
  2. Inexpensive
  3. Good quality helmet camera/video
  4. Good quality microphone/sound
  5. As much recording time as possible
  6. As much battery life as possible
  7. Lightweight
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Helmet Camera

Lofty goals indeed, but my idea was to focus on a budget and try to strike a balance. If I couldn't achieve my first four goals, I'd scrap the project (and since I'm writing about the system, I must have succeeded :) ). I started by reviewing helmet cameras in general online, from the Oregon Scientific ATC-2000, all the way up to the V.I.O. POV.1. However, because most consumer-level helmet/bullet/lipstick cameras are built for 1-30 minute sequences of motorcycle, trick sports, and free-falling type scenarios, battery life and recording time immediately became an obstacle I'd have to keep in the back of my mind as I researched the helmet cameras based on their image/sound fidelity.

'07 Twenty20 Helmet Camera
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'07 Twenty20 Helmet Camera

After finding a couple of helmet cameras that were high quality but still affordable, I settled on the '07 Twenty20 Helmet Camera. The deciding factor between it and the other I was researching was that it was not a fully integrated system. Most helmet cameras that are fully integrated (self-contained storage, battery, and controls) unfortunately make a trade-off. They generally store video data on a flash disk, so recording time is a limitation, and use standard AA batteries, so battery life is short. While disk storage is maturing (flash disks at the moment go up to 8GB), the helmet cameras are still limited to < 2GB cards. This is because they generally use FAT for storage of video files rather than its more modern variants, which support larger files. Lastly, if the fully integrated system touts being waterproof, they generally have poor sound quality, and changing batteries is time consuming because it requires a screwdriver.

My helmet camera of choice, the '07 Twenty20 Helmet Camera, boasts 16 hours of record time on a standard 9-volt battery and it is moderately waterproof (submersible up to 3 meters for 3 minutes IIRC). Its video and sound quality is very high and it stores data at roughly 1GB/hour of footage @ 640x480 and mono sound. For side-by-side comparisons of this helmet camera versus competitors, take a look at HelmetCameraReview.com in the references below. After usage, I discovered that the battery pack was the weak point of the system. The case that holds the battery would sometimes slip off, exposing the 9-volt battery to falling out. Further, the on/off switch on the battery pack would accidentally get flipped. Easy enough--a piece of electric tape over the switch and the case cover fixed those problems. The other issue: leaving the switch on would drain the battery--is one to keep in mind for after the race (batteries aren't cheap!). Because it is not a fully integrated system, though, I needed to find a device that would store many hours of video footage, have a long enough battery life, and also be waterproof. Again, lofty goals.

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Recording/Storage Device

Archos 604
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Archos 604

I considered two devices for recording. The Archos line of products (specifically the Archos 404, 504, and 604) and the Cowon line of products (specifically the Cowon A2). Now, because either of these devices would more than double the cost of the helmet camera, I was pushing the low-cost goal already. I would need to get extra value out of the device if I was gonna drop that coin on the helmet camera setup. So ultimately, this was why I decided on the Archos 604. It was on sale as the Archos generation 5 devices were coming in and it offered me the ability to give my wife an mp3 player for her walks (albeit a hefty one) and my sons a movie player for long car trips. For all of these options, the Archos 604 became the lead player.

Not only was the Archos 604 a tad cheaper than the Cowon, but it seemed to have better reviews, a more active community, and the thing that tipped the scales in its favor--interchangeable battery. The Cowon's battery, while lasting nearly twice as long as the Archos', was built in.

The Archos turned out to be a great mp3/video playback device, and has a ton of attachments and peripherals supporting it in doing this. There are, however, some fall backs in recording that I've experienced:

  1. A small annoyance, but a lot of the time, the Archos will prematurely "cut" the video 5-30 minutes into it. Normally, the Archos "cuts" the video as the maximum file size is reached. It effectively commits the video to disk, and starts recording anew using a sequential file. This is only an annoyance, but for every cut, there is a small chance the video that you wanted to splice was split down the middle during the cut, and so you wouldn't be able to use it.
  2. Seemingly random blackouts on the screen while recording (these are not the screensaver kicking in) where all of the buttons effectively become locked and there's no way out of it aside from pulling the battery or letting it drain down. If the player froze up 5 minutes into a session, you get 5 minutes of video, even though you might have carried around the helmet camera setup for 8 hours.
  3. Sometimes, the device doesn't fully commit the file to disk before it turns off, leaving the file corrupted. This is usually but not always linked with the blackout/lockup problem, I suspect because the device, once locked, cannot go through the power down cycle (where it writes the remaining bit of the file to disk before shutting down) and so the file is halfway-written. This problem is fixed by running the resulting corrupted .avi file through an AVI re-indexer.
  4. At random times, the Archos writes the file as a protected DRM file, where you can only view it from the player. Coupled with a corrupted file, the file is lost. In the best case scenario, you cannot copy the file to your computer and are forced to view the file from only the Archos in order to prevent you from violating your own copyright on it. Grrrr! Apparently, this is a common problem. Here's some forum posts about this problem:

Battery life for the Archos 604 is advertised at 16 hours for mp3 playing and 5 of video playback. I speculated that because it doesn't use the LCD, video recording would have the battery drained somewhere between the two numbers. I was wrong. In fact, the battery lasts 4 hours while recording. I attribute this to the hard drive use during recording. When solid state drives become more affordable, I imagine the battery life on portable media devices will greatly increase. For now, because it sports an interchangeable batteries, I purchased an extra one to trade out in TAs during races.

Then there is the issue of waterproofing. None of these devices are waterproof, and I couldn't find any cases for these devices that were waterproof and allowed cable pass-through. So, I'd have to make my own.

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Waterproofing

Otterbox 3000
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Otterbox 3000

Enter the Otterbox 3000. Because Otterbox allows their customers to download detailed specs and dimensions on their boxes, I was able to find one that fit the Archos 604 exactly. When everything is in the box, there is probably < 10cc of air left in the box. Enough space to keep everything snug but not so little that it is overly difficult to pack it all in.

One problem already mentioned was that there were no waterproof boxes that had a cable pass-through. The problem is that while the box's contents are waterproof, there needs to be a way by which the recording device on the inside of the box can connect to the helmet camera on the outside of the box--all without compromising the waterproof seal of the box.

With the Otterbox 3000, my only option was to make my own. So, I took out the old drill and made a hole big enough to pass the audio coupler's jack through it. Once through, I used a generous amount of silicon to make a waterproof seal around the cable. The cable coupler would now be part of the box.

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Mounting

Another issue to overcome was how to mount the helmet camera. Adventure racing takes people through the backwoods, bushwhacking through dense underbrush that grabs and claws at one's clothing. A helmet camera with a cable would be quite susceptible to getting pulled off of its mount.

3M Dual Lock Strips
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3M Dual Lock Strips

Lucky for me the search was short for how to mount it. Twenty20 provides some Twenty20-branded 3M Dual Lock strips to mount one's helmet camera. It was only a matter of time until I found out exactly what they were. There are different types of bonding strips out there--I would rank them as follows:

3. Standard Velcro

2. Military/Marine Grade Velcro

1. "Make-your-fingers-bleed" 3M Dual Lock strips

These interlocking mushrooms are the strongest bonding strips I have ever seen, and allow the helmet camera to take a beating and still stay on the helmet. I have had huge success with them in initial testing. With a 1"x1" strip, the helmet camera has been knocked/pulled off probably a total of four times. As a result, I have a backup piece of military grade Velcro on the helmet camera's cable attached to the helmet to keep the helmet camera from going far once pulled off.

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Connecting It All Together

To make the Archos work with the helmet camera, I also had to purchase the DVR Travel Adapter, a 6-Inch 1/8" Stereo Male to Females Y-Adapter, 1/8" Stereo Female-Female Coupler, 1/8" A/V Plug to 3 RCA A/V Cable, and a 1/8" Male to 2 RCA Female Audio Y-Adapter.

Connecting It All Together
External View
Internal View
Labelled Close-Up
Everything in the Box
  • The DVR Travel Adapter is an add-on to the Archos that enables it to use car/wall chargers (rather than just USB) and, more importantly, record from video sources such as with our nifty helmet camera setup.
Helmet Camera Connection Diagram
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Helmet Camera Connection Diagram
  • The 6-inch 1/8" Stereo Male to Females Y-Adapter is basically the shortest 1/8" stereo extension cable I could find. This is what I passed through the drilled hole in the box and then sealed it with silicon. I wanted it to be as short as possible, but still flexible, since it would become part of the box, and effectively, my waterproof pass-through. I went ahead and cut off one side of the Y to shed some weight, since I only need one cable. Of course I used some electric tape to seal it off.
  • The last 3 components are all for the seemingly simple task of converting the 1/8" A/V connection (stereo audio + video) into 1/8" A/V connection (mono audio + video). See the Helmet Camera Connection Diagram or the Labeled Close-Up above for how. Here again, I used electric tape, except this time to cut down on the mess of having that 6ft A/V to RCA cable in addition to sealing off the nub where I cut off one of the RCA plugs. If ANYBODY knows of a single part that can do this conversion (or at least a shorter A/V to RCA cable), do shoot me an email!
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Summary

As far as the usefulness/failure rates of the system and why, here's how successful I've been using it:

Track Record:

  • Bull Mtn. Ride: Frozen Archos after 1 hour. File corrupted but reindexed on computer later. Learned that camera requires different angle on bike than trek. Added more 3M Dual Lock Strips to accommodate.
  • Bear Creek Mock Race: Worked properly. Proved that 3M Dual Lock strips work well even when bushwhacking through some dense undergrowth.
  • Sope Creek Run/Ride: Copyright protection bug.
  • Lanier Paddle: Copyright protection bug on the larger of the two videos.
  • CP0 Adventure Race: Copyright protection bug on the larger of the two videos. Half of the good video black (audio still works) because video connector was not fastened properly after it was disconnected in TA. Snow on camera lens during a portion of video.
  • Mullet Ride: Copyright protection bug on the larger of the two videos.
  • Blue Ridge Adventure Race: Frozen Archos after 3 hours. File corrupted and could not be reindexed due to copyright protection bug.
  • Western Carolina Adventure Race: 1 video is fine. Copyright protection bug on 1 of 4 videos. 2 of 4 videos appear to be corrupted.
  • Paddling the Etowah: Significant waterproofing test (system was under 3-5 inches of water for 30 or so minutes). Confirmed microphone and Otterbox setup are waterproof. Screen slowly blacked out 40 minutes into recording, though. I believe this was due to the helmet camera's 9-volt battery being dead, even though tongue-testing it later indicated it had a charge. I was afraid the camera sustained water damage, but after I got home I tried it and it worked fine.


Weight is another thing. Adventure races take the competitors over very long distances and the more weight one can shed, the better. It is not often that people volunteer extra weight, so here is an estimate of what you're carrying:


Weight Total: ~47.97oz (3.00lbs)

  • Archos 604: 9.05oz
  • '07 Twenty20 Helmet Camera: 4oz
  • Otterbox 3000: 13.92oz
  • 9-volt battery, added adapters and cables, Archos case: ~10oz
  • Bicycle Helmet: ~11oz (only additional on sections where it wouldn't already be worn)


There are also considerations to be made for the amount of encumbrance such a system adds to the racer. Not only is there additional weight, but there are additional cables, consumed pack space, and the need to disconnect every time the backpack needs to come off. A battery change requires getting into the pack and Otterbox, shutting down the Archos, replacing battery, powering up Archos, and starting the recording again. This whole series takes about 5 minutes to do. It will mean losing a place or two during your races due to the additional transition time.

Speaking of additional components one is forced to carry around, here is the breakdown of this system, in case you want to duplicate my setup:


Parts: 


Final Statements:
Overall, I'm neutral to negative on the helmet camera setup.  On the positive side, 
I have gotten tons of footage, even though there were many kinks to work through.  
And in general I have met all the initial goals I set out to attain, but the death 
knell so far has been the software bugs in the Archos.  All of the major problems I
faced have pointed to it.  It is really frustrating to lug extra weight around an 
entire race and end up with a mere 30 minutes of footage.  It is even worse to 
capture some great video during a race only to come home and find out it has been 
copy-protected by the Archos.  If I were to go out and put together a helmet camera 
system all over again, I would probably try a different recording device such as the
Cowon A2.  I also think it would be beneficial to wait until a device with a good 
battery life that supports an >=8GB flash card comes out.


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References

Retrieved from "http://www.teamrocgear.com/w/Helmet_Camera"
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