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shodan

Need help improving my timing system

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Hi All,

As per title I need some help- I'm getting false laps counted during use. Most of the time the system seems to work well, with the occasional short lap getting triggered. And very occasionally, laps being triggered on a different lane. Frustrating.

I've got 5mm ZD1945 emitters in the timing gantry,  and ZD1950 IR transistors in holes in the track next to the braid. The transistors are connected to a genuine Arduino Uno. I've used decent quality silicone wires back to the arduino in my track control box in a run of perhaps ~1100mm long. The grounds for the transistors are joined at ~300mm in that length (so 6 wires for 300mm, then 4 wires for the remainder).

Control box:
d8rjjF4.jpeg

I was getting a lot of false laps triggered and partially resolved that by dropping the sensors lower into their holes in the track, but I'd appreciate input on how to make the system flawless if possible..
 

Does powering the arduino separately help?

Are there improvements I could make to the circuitry?

Could I put the sensors in the gantry to remove as much ambient light triggering as possible?


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Two suggestions

Try a small capacitor across each lane, the ones off Scalex motors usually work well.

If thst does not fix the problem try the grounds should be kept seperate right back to the board.

Your set up is the same components that I have been using for 20 years.Had the same problem on one track and the capacitors fixed it. The other track required both the above

Phil

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Phil

 

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Thank you Phil, nice to hear from you.

Hopefully I've got some scaley motor caps lying around, I'll apply them first - I assume they should bridge the rails for each lane after the controller output?

See how it goes, then separate the grounds if that doesn't help


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I fitted the capacitors between across the braid near the lap sensors, simply because there were power connectors there.

I think some PCs seem more sensitive to this than others.

Another problem I have had is with people using a controller with full power relays, but fitting a diode across the coil of the relay fixed that.


Phil

 

Hobart Miniature Car Club

 

Tassie Resins

 

Email

 

 

 

 

 

 

Logos%2016_17.small_zpswkcwjf0q.jpg

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I hadn't even considered the PC.. I guess it could be an issue because it's the only ground source for the arduino, via it's usb connection.

The controllers in use are 2x professor motor and 1x SCP-1 which I don't think have full power relays


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Well I seem to have achieved success,  thanks for your help Phil.

Added caps across the lanes (104's from scx cars, easiest to harvest )
Extended ground wires back to arduino

These fixes resolved most issues however I was still getting occasional wrong lane laps- the final piece of the puzzle was to cover a fluorescent light mounted on a wall near the track.


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