|
|
This is a revision of my origial system described at RC Camera. For details on the electronic interface between the digital camera and the RC system please go to RC Camera.
The only change I have made to the interface is to hotglue the LCD 7 segment module back onto the camera so that I can see what the camera is doing. A rubber band is also necessary to provide the small amount of pressure necessary.
A further modification in future would be to remove the battery eliminator circuitry so that only the PICAXE is supplied by the RC battery and the camera would retain it's own battery, possibly an AAA battery. This would probably save a lot of grief as I find that I need to be very carefull with the steps required image retrieval with the current system - these are:.
The important changes are to the software to allow the user to put the camera into video mode. You can download the revised PIC AXE 08 program but it's so short I'll just show it here too:
loop1:
high 4 ' leave PC mode
input 1 ' exit failsafe
input 2
loop2:
pulsin 3,1,b0 'RC input
if b0 < 180 then loop2 ' failsafe & no action
low 4 ' turn PC mode off
pause 500 ' give camera time to settle
w1 = 0
loop3:
w1 = w1 + 1
if w1 > 100 then vidmode ' > 1 to 2 sec
pulsin 3,1,b0 'RC input
if b0 = 0 then loop1 ' repeat off on
if b0 > 170 then loop3 'wait for shot
high 1 ' trigger shutter
pause 500
input 1 ' return trigger to high impedance
pause 1500 ' give it a chance to trigger
goto loop1 ' PC mode to keep camera on
vidmode:
w1 = 3
loop4:
high 2 ' mode
pause 300
input 2
pause 300
w1 = w1 - 1
if w1 > 0 then loop4
high 1 ' trigger shutter for video
loop5:
pulsin 3,1,b0 'RC input
if b0 = 0 then loop1 ' repeat off on
if b0 > 170 then loop5 ' video being taken
input 1 'end video
pause 2000 ' let things settle
goto loop1
This operates much as before except that if the RC channel has a long pulse for longer than about 1 to 2 seconds then the camera will go into video mode and stay there until the pulses go short again.
It takes a couple of seconds for the camera to enter video mode and begin filming. I or you need to add some glitch detection because my current films have been broken into smaller chunks by these glitches. To do this, add some more counter loops around the threshold detection.
Also note that I have changed the pulse threshhold levels so that it operates with two different transmitters. An automatic pulse length detector (one that adapts to longer and shorter pulses and uses the average as the threshhold level) would be nice. There is still plenty of room in the PICAXE program memory.
If anyone wants to send me improvements to the picaxe program, please email me at:
A couple of frames from my flights:
Fantastic photos aren't they. Choke!
You'll notice the bars across the image of the tree (which I was about to hit). This video was taken when the light level was high and so I think the shorter exposure time has caught the propeller in action. Or it may be interference from the motor electrics - the battery was getting a bit low at the time.
In the second frame, the light level was much lower and so this was the clearest of many blurred frames.
Not much future really but it was a fun project. I'm also interested in horzion detection for small aerial vehicles, so the next stage was to add a panoramic mirror .
Have a quick look at my RCcamera and panoramic mirror pages.
If this wasn't really what you were looking for in aerial camera's there is a good chance you will find it at one of the following sites: