Archive for February, 2011

Camera Axe 5 Contest

For those not familiar with the Camera Axe or what it does check out

In the past I’ve always designed a product and then released it as open source when it’s done. While this seems to be the more common model for open source hardware, it obviously isn’t ideal since the community feedback won’t have an impact until the next version. This time I’m publishing an early rough version of the new Camera Axe hardware and having this contest to see if we can improve it before I finalize the design.

I’m planning to give away one of the new Camera Axes when their done to the winner. If the winner would rather have $100 credit on my store to buy sensors today I will allow that substitution. The winner will be chosen by me based on who I think gave the most helpful information. My decision is final. This could be a fix in my board design, a suggestion on how to save costs, a better part recommendation, a new feature, or anything else that helps me. To enter the contest you can either leave a comment at the end of this post, or you can also email me (ribblem ‘at’ If an idea shows up more than once the first person to suggest it will get credit. After the contest is done I’ll contact the winner via email. If you leave a comment below as admin I can see your email you enter so make sure you use the correct email. If I can’t reach the winner in 3 days I’ll try to contact whoever I thought was the next most helpful.

Here are the alpha PCB files for this new version of the Camera Axe.

If you have questions ask them below and I’ll do my best to answer them. Have fun and lets make the best Camera Axe possible!

Here’s a list of some of the big changes in this design since the previous version of the Camera Axe. These areas of the circuit would be the areas that most likely have bugs or could be improved.

  • Started using surface mount parts. The plan is all the surface mount parts will be pre-soldered even for the kits. This will make the kits easier to assemble. I needed to do this because the board is much more complex and some parts where only available as surface mount.
  • USB port is now included and an FT232 chip so no special FTDI programming cable is required. The USB port will also power the device.
  • Reworked the battery system to use a more efficient boost converter instead of a linear regulator. This also let me reduce the batteries from 6 AA to 2 AA.
  • Various other power efficiency improvements (Mosfet, better resistor choices, …).
  • Included an ICSP programmer header.
  • Added an LCD constant current source to more efficiently power the backlight. This will reduce power usage by more than half.
  • Added some 1M resistors to ground on the sensor ports. Hopefully this will fix the floating sensor pins when no sensor is plugged into a port.
  • Filter caps moved closer to pins they are filtering to reduce noise.
  • Added IO protection to the sensor pins.
  • Reworked Sensor1/2 pins so they should be more flexible for future sensors while maintaining backwards compatibility with existing sensors. These changes should allow IC2 sensors or a stepper motor controller per sensor port.
  • Lots of other little improvements.

This contest will be open through at least February 20th, 2011. I will update this post when it is officially closed.

I’m sure people will ask when this version will be done. The answer is that I’m not sure, but I hope to have it done in four months or less.

Update 1

Here is a list of changes I’m seriously considering. Basically I have added these to my PCB files and will only remove them again if I have a good reason to do so.

  • Integrated to a new and better boost converter to create 5V.
  • Added an Lithium battery charging circuit and plan to include a rechargable battery. This will increase cost a little, but get rid of the many problems mentioned about not having a battery compartment.
  • Added dedicated buttons to trigger camera/flash ports
  • Switched to a two color LED that connects directly to the shutter/focus pins on camera ports 1/2.
  • Added a battery charging LED.
  • Reworked a lot of the part layout to get filter caps closer to the pins that need them.
  • Added an internal header on the board for an optional real-time-clock board from sparkfun. This will require lots of code changes and I’m still unsure if I’ll support yet.

Update 2

And we have a winner. Congrats PTB! I’ve contacted him and he said that his version 4 is serving him well so he’s wants to wait for version 5.

While this officially ends the competition feel free to leave other ideas you have in the comments or post them to the Camera Axe forums. Ideas are always appreciated!

I’m going to finalize the PCB design and send for a few to be made. Then based on experience I’ll need to do at least 1 respin on a board this complex. Then I need to verify the final board version and hopefully the new software will be written. Then I know to get quantities of some of the parts is 8 weeks of lead time. Basically I think best case it will be 4 months before I have everything ready for a release, and it could be significantly more time. We’ll see how close this prediction is…

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