I would like to share an airsoft - paintball chrono that I made.
"Underspeed Chrono Light"
Version: 1.0
Last modification: 08.01.2016
Some tecnical info:
Set AVR clock to external crystal.
LED:Any IR (infra red) LED.
Best under 60 degrees
7 segment LED display: common cathode, common sticks.
For example:
KINGBRIGHT ELECTRONIC BC56-12SRWA
http://www.tme.eu/hu/details/bc56-12srwa/harmas-led-kijelzok/kingbright-electronic/#Phototransistor:Many type working well.
I tested BPW17 and SFH309FA phototransistors.
PCB size:81mm x 85mm
!!! LED1, LED2 polarity is WRONG on the schematic !!!
I like it ....
I wish I still used my paintball guns again but might build your setup for my brother though..
hello
so i build it, but its not working, and i would like to know why.
when i turn it on, the display start blink (at frequency like 25hz), and show just three zeroes.
i used 1n4007 instead of 1n4004, and ATMEGA8A-PU instead of ATMEGA8-PU (i couldnt find this, and "google say" they are the almost same,)
could anything of that make problem?
I think the problem could be the avr clock setup.
You have to set clock source to external crystal (high fequency) and disable CKOPT.
Check the first post, I attached display of clock setup.
i am finally reprogrammed processor, display works fine now, but dont measure.. only show 3 zeroes.
i used R1-R7 = 150 ohm (but this shouldnt matter, it can be 150-220)
btw, R11 = 91 ohm? (just to be sure)
i don´t know exactly what IR LED i used, it looks like this one
http://www.sos.sk/?str=371&artnum=11936&name=kingbright-l-53sf4bti mean, can dark color of the LED be a problem?
everything else (except what i alredy wrote in previous post) is same as your
edit: i tried IR led from old mouse, but still no output on display..
Hi!
btw, R11 = 91 ohm? (just to be sure)
Yes, R11 is 91 Ohm, but best if you measure IR LED current, and you choose correct resistor value.
i mean, can dark color of the LED be a problem?
IR LED with filter is good. You can check the lighting, with a camera or phone.
And check the PD2 and PD3 leg with multimeter. Measure voltage there, after cross the light and measure again. Share the values.
i changed R11 to 47 ohm (added 100 ohm parallel).
i measured PD2/3 before and it was 5V/3V, now it is 5V/2V and the chrono works correctly.
i thought cameras have IR filter therefore little ir light is see. Becouse of that i didnt realized LEDs shine too weak
Thanks for your help!
Hi
so i build it, but its not working , the 7segement not show any thing !
please help me
How are you timing the delay?
Are both light sensors on hardware interrupts where you start the timer on one and read the value on the other?
so i build it, but its not working , the 7segement not show any thing !
I think program isn't run. Please search an AVR topic or tutorial to find the problem.
Are both light sensors on hardware interrupts where you start the timer on one and read the value on the other?
You think well, just a little different. Timer is always run. I reset at 1st interrupt, and read at 2nd interrupt.
Hi dear vzoole
may you tell me how to program your ATMega8 ?
I have STK500 Programmer , but i don`t know how to program my ATMega8
thanks
hi friend
I built it again butdn't work
I program atmega with stk500 by avr studio 4 ,but 7segement don't show anything
Please help me
Check clock and display outputs on AVR with scope.
nice little project.
Thanks for sharing! D
Nice project! What is is actually displaying? MPH, km/h, inches per second, just the time between?
Thanks!
-Tim
Thanks!
Actually show FPS in video.
Hi,
I made your chrono but it not work correctly. Slow speed show (under 20 fps) but higher speed no....I use phototransistor SFH309 and I programmed in Pony prog becouse I have only LPT programer and in AVR studio not work. Do you tested it with airgun cal. .177?
Hi!
Maybe you doesn't switch off CKOPT option that is dividing the clock by 8.
So if you measure 20FPS that could be around 160FPS in real ( 20*8 ).
So please check the FUSE bits.
Install the software on a chip (Chrono_light_01_mPs.hex), but does not work. What should be the current work? What could be the reason?
How much should be volts?
Minimum input voltage is 7.5V
Current without controller (only IR LEDs): ~30mA
With MCU and working 7 segment display: ~110mA
If you have no current flow you have supply problem.
very nice project
i want to make one but im complety dummy for project
can you tell me what exactly i need parts for this porject;
example;
2x diode
1xatmelxxxxx
i readed first post but missing somethings like ressitors
2xphototransistors
2x ir led
1x atmega8pu
1xusbbasp for programming
....others ?
i can see in picture but i dont know names
there is no voltage on the LED (red circle on the picture)
can you tell me what exactly i need parts for this porject;
You can find parts in schematic in zip file at first post.
there is no voltage on the LED (red circle on the picture)
Check the input voltage on regulator input.
Hi friend. Which firmware to measure in meters? Chrono_light_01_FPS.hex or Chrono_light_01_mPs.hex