Help troubleshoot inconsistent timing system
Heya, just a noobie bringing in an outsider's perspective: Are you by chance lighting your area with flourescent or LED lighting? Try turning all those off and using an incandescent lamp if you need light. It could be those lights flickering at 60Hz or whatever the frequency flourescent ballast is using.
- Oh, good observation — dr_dodge
- Time for a test in the dark. I'm game. — Late_nite_racer
- feedback? — dr_dodge
Late_nite_racer, how did this ever turn out for you? I had a thought after reading the previous comment about Flourescent or LED flicker. It could also be caused by a shadow from the car in the other lane. That could explain why the time difference changes with the opponent. Is your light directly overhead? Or off to one side which would cast a shadow from the car.
I have a homebuilt Arduino based finish line and timer using cheap photoresistors. The timer starts electonically when I push the START button. No microswitch. But I do need to program the sensitivity of the photoresistors if I change lighting conditions. I'm guessing you can't do that with Slanman. I hung a spot light directly over the finish line to provide a constant bright light level regardless of the other room lights.
I have inconsistent times too, but its due to slop in the starting gate linkage. It's a JLH Krafts starting gate. I will be switching to a Slanman or Spoolheads once I can confirm that I can trigger the it with my Arduino.
I hope you've been able to solve your problem since the last post. This threads been quiet for a few months.
Chris
- movement and "ringing vibration" is a killer for either sensor, launch sol shakes, cars hit the final approach is just as bad, and the actual track (heavier car bow wave effect) — dr_dodge
- I don’t know the electrical details of the timing system or switch - but in general (meaning all the time) you cannot just add a mechanical switch to a micro-controller input. It needs to go thru a ‘debouncer’ circuit of some kind OR you’ve coded in some code that acts as a debouncer. Otherwise you can get multiple logic level transitions from the switch being thrown. — AbbyNormal
- solenoids need the same thing electrically, otherwise they load/spike/unload the supply voltages — dr_dodge
- @AbbyNormal and Dr Dodge. Yes, I have programmed in Debounce. Thanks for the input! — Zamak_Speed_Shop
- Just read your post more closely - photoresistors can have significant delays in switching Hi/Lo a better choice is IR based transistor and hopefully you are using interrupt sub-routines and not a polled method. Are you seeing measurable differences between successive runs? — AbbyNormal
- I agree completely about IR. I have the parts sitting there waiting to be installed. I used the photoresistors at first as proof of concept. I since ordered some IR pairs but haven’t installed them yet. Too busy building mail in cars. Lol. My start gate is crap and has a lot of slop. Servo controlled with no end stops. It’s not controlled by the Arduino (yet). That’s where all my inconsistencies come from. — Zamak_Speed_Shop
- My timer is setup similarly with it starting based on the push button which simultaneously tells the gate to open. But the real reason I wanted to respond was I've been using Adafruit IR Break Beam sensors on my finish gate and haven't had any false finishes at all. The light emitter sits above the track and the sensor rests below. I've also been using dfgtech.com's free software with some tweaks. — X2Whiskey
- X2Whiskey Glad to hear the IR is working good. I'll get there when I have some spare time this winter. Thanks for the info — Zamak_Speed_Shop
I can't remember where I seen the video or who even made it. But there was a guy who did a video using light shining through a small pin hole on his start gate. The video was filmed in slo-motion and showed the vibration from the start gate dropping. This was giving him uneven starts and inconsistent timing. He corrected it by placing some dampers on the gate. Redid the video and showed a significant improvement in the vibration from the gate being tripped.
I have the same sort of drop gate and a Don Boomershine finish line and my times were inconsistent until I placed some dampers on the gate where the bracket/drop pins hit the main body of the gate.
- I recall that video too. Mine has a 9gram servo to drop the gates so no vibration — Zamak_Speed_Shop
- Glad you were able to get yours straightened out — Zamak_Speed_Shop
- never underestimate using 1" washers in the track to give it mass. they just slide in the grooves. my launch track on jamestown has 10 on each side. It dampens the track movement upon launch. — dr_dodge
I know Elevation diecast racing uses the Slanman timer for his Johnny Lightning track and seems satisfied with it. It would be interesting to hear his thoughts as well as other users. Mine may just be a bad apple.