I need to be able to calibrate a camera's reported framerate against a known framerate. I'm using java to strobe a parallel port to blink an LED in front of the camera's lens. I'm using timers and actionevents to try and make a blinking light with a one second frequency.
Unfortunately, my one second is blatantly incorrect.
Is there a better (software) way to do this? I'm considering just making a piece of hardware to do the job, but that's messy.
Timers aren't terrbly accurate. I'm not sure what is accurate in Java (I *think* you can get realtime rates with it, but not sure how). You may be better off using C. (Did I just recommend something other than python?????)
You could do it with about $3 and a soldering iron
a 555 timer chip
1 Mohm resistor
100 ohm resistor
0.1 uF capacitor
9 volt battery, or 5-9 volt outlet transformer (old cell phone?)
1M resistor * 1uF capacitor will give you a period of 1second
I'll try this in ascii art:
+-----++++++[PWR]-------------+ | | +--[1M R]-+--+---+--[1uF C]---+ | | | | | | _______|__|___|__________ | +-[/RST D Thr Trg ] | | [ ] | | [ 555 timer Gnd]--+-------------+ | [ ] | +-[Vcc Out]--[LED]--[100 R]+
CLR pin Not Connected (NC)
Yah..I was just about to say that. You totally beat me to the punch..
Nice ASCII art phrak!
This has GOT to be the nerdiest thread I've seen in a while. 8) Cheers!!
Bah, that's like Freshman Electrical Engineer stuff - if you like I can throw in some VHDL for the same thing and give you a good source for an FPGA so you can upload the logic there (of course, the pin-outs would have to be modified based on the board).
Would you like VHDL for a router? I have that floating around somewhere too - oh and VHDL for an N-bit RISC processor (w/o FPU)...
/me nerds all over you