Airsoft - paintball chrono

#26 Reply
Posted by UA on 11 May, 2014 14:07
Please help. I suffer for a month . Brazed chronograph programmed chip. When connected to electricity is off 7 segment LED display. Watching through a mobile phone camera, LED work.
But when I turn the 7 segment LED display, light some segments.
Help razobratsya what could be the problem. Thank you.

#29 Reply
Posted by dannyf on 11 May, 2014 18:57
The DP line is not connected so DP should never be on.

Either your leds are misaligned (wrong orientation) / polarity is wrong, or the wiring is wrong.

You can correct them, or find out the real wiring and write your own firmware to it.

#30 Reply
Posted by vzoole on 11 May, 2014 19:02
I checked this display and fit well in this circuit (but not upside down).
So the problem is something else.
Hard to do anything without an oscilloscope.

#31 Reply
Posted by UA on 11 May, 2014 23:02
Does a problem mean not in 7 segment display? Do I understand correctly? A problem means or in details or I not correctly zaprogramiroval chip.

#32 Reply
Posted by UA on 12 May, 2014 13:06
Connect power chronograph 7.5 volts. Multimeter measured current: LED - 1,18 volts, phototransistors - 0.05 volts.
Again, instead of chip ATMEGA8-PU I have is ATMEGA8A-PU.

#33 Reply
Posted by vzoole on 13 May, 2014 22:10
Can you measure voltage on resistors leg (at mcu side) which are between display and mcu?

#34 Reply
Posted by dannyf on 14 May, 2014 00:00
If I were to desing something like this, I would do it different: I would build it around a barrel (like a piece of pvc pipe) that can be mounted easily onto the gun. The sensors can be fixated to the side of the pipe and the display bounded on a pcb along the pipe.

It would be more rugged that way.

#35 Reply
Posted by UA on 16 May, 2014 21:50
9 volt power supply. I measured the voltage across the resistors between the display and the MCU. Resistors R1-R7 (180) is zero. No stress! Resistors R8-R10 (2.2K) is 1.4 volts.

#36 Reply
Posted by UA on 16 May, 2014 21:53
Quote from: dannyf on 14 May, 2014 00:00
If I were to desing something like this, I would do it different: I would build it around a barrel (like a piece of pvc pipe) that can be mounted easily onto the gun. The sensors can be fixated to the side of the pipe and the display bounded on a pcb along the pipe.
It would be more rugged that way.
Here's a link to a chronograph http://chronolite2.narod.ru/ But I believe that Airsoft - paintball chrono much more practical and convenient.

#38 Reply
Posted by UA on 16 May, 2014 22:24
Measured. Resistors R1, 3,4,5,6 - 5 volts. R7 is no voltage - zero. Resistors R8, 9,10 - 0,25 volts.
I measured at these points

#39 Reply
Posted by vzoole on 16 May, 2014 22:38
Quote from: UA on 16 May, 2014 22:24
I measured at these points
Thats bad, because I asked you measure on resistor leg but which is next to the controller.

#40 Reply
Posted by UA on 16 May, 2014 22:45
Measured at these points
Resistors R1, 3,4,5,6 - 5,05 Volts. R7 is no voltage - zero. Resistors R8, 9,10 -. 1.65 volts

#41 Reply
Posted by vzoole on 16 May, 2014 22:51
It's looks good. Can you take a picture about your transistors type?

Or make a short contact between the transistor two side leg for short time. What does it show then?

#43 Reply
Posted by UA on 16 May, 2014 23:48
And maybe the transistor. Need BC546, and I used BC546B. Maybe that is what affects the inefficiency?

#44 Reply
Posted by vzoole on 16 May, 2014 23:49
Not...

Try this: make a short contact between the transistor two side leg for short time. What does it show then?