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The CamMan family of camera projects is used to turn an ordinary digital camera into an R/C controlled wonder. With CamMan installed, nearly anyone can take beautiful aerial photos from a small R/C (radio controlled) model airplane. CamMan was originally introduced with the CamMan-Aiptek Mini PenCam camera project. But this time the host camera is the nifty Aiptek PenCam SD 1.3M. If you are not using the SD camera then check out the other CamMan projects to see what camera models are supported. The basic modifications center around a small circuit that uses a microcontroller to decode the R/C servo signal, as well as manage the camera interface. In the case of the Aiptek modification, only three parts are needed; an 8-Pin IC, capacitor, and resistor. But as simple as that sounds, this is NOT a project for an inexperienced electronic tech. Advanced soldering skills are needed due to the fine pitched soldering that is required inside the camera (digital cameras are tiny!). If you are not comfortable with precision soldering then please consider the old standby solution -- glue an R/C servo to the camera and have it push the shutter button. This old trick has been used for decades and works well. CamMan-SD offers these features:
PIC Chip: A Camera Man's Best FriendCamMan is based on a tiny 8-Pin chip. It is actually a MicroChip Technologies PIC12C508 microcontroller that uses custom firmware that you can download at no-charge. The PIC decodes the R/C signal for shutter activation and (optionally) manages the power up state of the camera. Even though a microcontroller is used, cost is very low. You can build the CamMan circuit for about $10. Total parts count is very low the assembled circuit weighs just a few grams.
The digital inputs are level sensitive and are said to be logic High when the voltage is > 2.0VDC and logic Low when they are less than 0.5V. Typical designs will use the VCC voltage (pin 1) for a logic highs and GND voltage (pin 8) for lows. The output sink current is 20mA (plenty for our application). Let's take a quick tour of the various signals on the PIC chip:
Your exact PIC choices have some flexibility. You can use a PIC12C508, PIC12C508A, PIC12C509, and PIC12C509A. Project Update: You can also use the easier to find PIC12F508 or PIC12F509 instead.
The PIC12C50x is not
a "Flash" part, so you will need a traditional
PIC chip programmer to "burn"
the hex file's object code into the microcontroller. Be sure to select the
configuration fuses during chip burning as follows (these are optional settings
within your chip programmer's menus):
The PIC's Hex file is designed to automatically instruct the programming hardware to chose these values. However, it is always a good idea to check them for accuracy. By the way, after you program the PIC your programmer will report a failure if you attempt to verify the PIC again. Do not be alarmed -- everything is OK. Just ignore the "failure." Whatever you do, do NOT program the chip twice! If you have trouble burning the PIC, then please check your programmer. Whatever the fault, it is not a RC-CAM hex file issue. The most common problem is that the user has forgotten to burn the PIC's four configuration fuses, as mentioned above. More programming information can be found starting here.
Dead BugsThe PIC's circuitry is so simple that a circuit board is not needed. All the parts are mounted on the bottom of the PIC chip, using "Dead Bug" construction (just picture a dead bug lying on its back). For this project I recommend a 40 watt or less soldering iron with a temperature controlled tip.
Start by trimming the PIC's DIP leads to about half their normal length. The skinny through-hole portion is simply clipped off. The photo on the left shows the details.
Add a jumper wire from pin 5 to pin 1.
Assembly of the basic
PIC circuit is now complete. All that remains is to add it to your camera.
As it turns out, the tough work is about to begin.
Micro Surgery: Wiring the CameraLet's get down to the business of wiring the Aiptek Camera to the CamMan PIC. All of the camera connections use 30 AWG Kynar (wire wrap) or enamel insulated magnet wire. If you use heavier wire then you will probably have trouble reinstalling the camera case.
The camera has two
screws that you must remove. They are shown in the photo on the left.
With the camera case
apart, remove the two screws that hold the battery chamber in place.
The chart below shows the basic wire connections. The "Photo ID" refers to the wire references shown in the photos found a couple paragraphs down. Be sure to review the schematics to verify you are wiring things correctly.
Use 30AWG wire to connect the PIC IC to the camera's circuit board. After the PIC is soldered to the camera it will be insulated with heatshrink or tape and placed in the empty space near the view finder and battery holder.
As shown on the photo
to the right, PIC Pin-3 goes to the camera's shutter
switch.
The R/C signal wire of the servo cable goes to the 4.7K resistor on PIC pin-4 (not shown).
File a thin grove in
the bottom of the plastic case to allow the servo cable to pass through.
Add a dab of adhesive to strain relieve it. Double check your work. Simple mistakes can destroy the camera, R/C gear, and may generally ruin your day.
Insulate the PIC with
heatshrink or tape and place it in the empty space near the viewfinder and
battery holder. Reinstall the various camera pieces and covers. You are
done!
Set Up and Operation:I will assume that you will be sharing your throttle channel with CamMan. Connect the camera to the R/C receiver's throttle channel and to the servo or ESC (electronic speed control). Turn on the R/C transmitter and apply receiver power. Even with no batteries in the camera, you should hear the camera beep when the R/C receiver is turned on. First you must "Arm" the system. Move the throttle stick to full low stick then give it full up stick (do not cheat -- use FULL deflection on both extremes). CamMan is now armed. The arming procedure only needs to be done anytime you apply power to the camera. You are now ready to shoot photos! If you reduce throttle to below 1/4 stick you should hear the camera beep as it stores a photo. To take another photo you must go above 3/4 stick, then back down again. Practice a bit -- you will quickly see how it works. If the camera does not take photos then you may have a wiring problem, your stick's trim lever is too offset, or an insufficient ATV mix setting in your R/C transmitter. First you should check your wiring. If it looks good, and the stick's trim lever is centered, then you will need to increase your ATV mix settings (if available) so that they are at 100% or higher. If you are using another channel besides throttle, be sure that its Dual Rates mix is disabled.
If you are using a
spare R/C channel (the gear channel works well) then the operation is nearly
the same. To perform the initial system arming just flick the channel's toggle
switch down then up. From then on you have switch controlled access to shooting
photos. If the switch operation is backwards then either use your transmitter's
channel reversing feature or ground PIC pin 7 (CamMan Reverse
option).
Design Documents:The technical details are available as file downloads. There is no charge for the information when used in a personal (hobby) project. Commercial users must obtain written approval before use. Please be aware that the information is copyright protected, so you are not authorized to republish it, distribute it, or sell it, in any form. If you wish to share it, please do so only by providing a link to the RC-CAM site. You are granted permission to post links to the web site's main page (http://www.rc-cam.com/). Please respect this simple request.
The Small Print:
All information is provided as-is. I do not offer any warranty on its suitability. That means that if you build and use this device, you will do so at your own risk. If you find software bugs then please report them to me. I can only make corrections if I can replicate the bugs, so please give me enough details to allow me to witness the trouble.
FeedBack:I would enjoy hearing from anyone that uses the CamMan system. Please send me an email if you build it.
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