DIY Affordable Track Timer 

Thanks so much!

Thanks! Sorry for not noticing, I'll hop over there and respond asap

Awesome! Let me know if you need any help along the way :)

Thank you! Good luck with your project :)

Thanks! Yes you can use that sensor however be aware that its range only goes up to 80 cm or .8 meters, which is slightly less than three feet. Keep that in mind as it will work for running right next to the sensor but not for the further out lanes

Hi Kian, it's been a while since I've worked on this but I believe the font sizes were 9 and 14. If not I'd just play around with the font sizes on FontConvert as anything that isn't the right size will look different than what is shown in the video. Let me know if you need more help

@@CollinWentzien thank you for the info. I'm going to give it a go when i have the screen working.

Yes you definitely could!

Hi Joshua! 1. I think that should be possible, but my only guess as to how you would do that would be using the latency between the two modules to determine distance. Otherwise your best bet will be to measure out distinct sections with known distances 2. Yes this is totally possible with a second lidar sensor. The code then just needs to be changed to start the timer when the first beam is crossed instead of a button pressed. Let me know if you have questions/concerns. Hope this helps!

Hi Grayson, Yes, the LIDAR sensor should be accurate enough for that as it has a frame rate of up to 1000Hz (1000x a second). The only semi-inaccurate part of the system is the timing itself, as the Arduino isn't the most accurate for that. I would suggest using a RTC, or real time clock, module for more accurate timing.

Awesome! So glad to hear that you were able to get it to work (for the most part!). As for fitting the project into the cases, I have added pictures of the insides of the track timers to GitHub (github.com/CollinWentzien/track-timer ). Also, if you could let me know what needs to be updated on the parts list, that would be great. This definitely can time multiple races, although an issue might occur if two people are side by side. For this, you would just need to know the distance each runner is from the sensor to know what lane they were in, and then match that time with the lane. Let me know if you need any help with that. Thanks!

@@CollinWentzien Which CAD application did you use? I need to modfiy to use a UNO in both :)

@@kevinberry5994 I used Onshape, but other programs such as Fusion360 should work fine as well. I didn't use an Arduino Uno on one of the modules since I couldn't get it to fit, but it'll definitely be fine if you expand the case.

@@CollinWentzien Thanks Collins. I could print and update boxes to make room for an RTC. However, I cannot update the code to add the 00:00.00. I could print, but the hundredth would not calculate properly; instead, I was getting 00.00.0000000.......0. I have watched many videos :). I could really use your help. I read your comments to others, but that didn't work.

@@kevinberry5994 so you're trying to round the .00000000 to 2 decimal places?

Hi! Thanks for reaching out. Sorry I don't check facebook often (actually never) but I'm a bit more active on here :). In terms of keeping time without an RTC, I just use the Arduino's internal 16MHz clock to keep time. You can't easily keep time with the delay() function, as it pauses all code for that set amount of time. Instead, I use the millis() function, which prints the system time in milliseconds. I also have another variable called prevMillis (or something like that). So, when the current time, or millis(), is 1000 over the previous time, we know a second has passed. We then set prevMillis to whatever millis() is currently and continue that cycle. Hope that makes a bit of sense since its sorta hard to explain haha

Hi! To be completely honest, I did not get an exact number for delay, but I did do some eyeballing and it seems to be pretty much instant. If you wanted to fix some delay, I'd have the modules run a test when first powered on to send a packet and see how long it takes to receive the packet. In my opinion, the lack of a RTC module is more inaccurate than the potential delay haha

Hi, to add another digit for the timer, you would want to add another variable for hundreths of a second and increase it every 10 milliseconds, or 0.01 seconds. When it reaches 10, you could increase tenths of seconds (that part is in the code), etc etc. There is a part in the code where seconds and minutes are increased, add the hundreths function there.

@@CollinWentzien so the part i need to change isit at the get_time function ? and how about the display.print(String(m1) + String(m2) + ":" + String(s1) + String(s2) + "." + String(s)+ String(ms)); in the fdraw app function, do i need to add the hundreth second variable as well?

@@kimvuivoon4858 yes you will need to add the hundreths variable in the print() fuction to view it

@@CollinWentzien hi collin, by adding another last digit to the timer, i used micros() instead of millis(). the new added last digit of timer display micro sec as if the stopwatch timer which is what i want. However, the second digit which should be run as a millis time , it run much slower than the millis speed which make the timer delay many second. may i know what shall i change for the coding?

@@kimvuivoon4858 the Arduino clock is not very precise unfortunately, meaning that 1 second is around 950 arduino millisenconds instead of 1000. By using micros() this error is magnified. You can try decreasing the delay period, but if that doens't work, you might need to purchase an RTC module (real time clock) which will provide more accurate time readings.

Hello! 1. Yes you can totally use two LIDAR modules in tandem. Just copy some of the code from the finish module that processes the LIDAR information over to the start module code and it should work. 2. As long as you set the two module pairs at different frequencies, they won't interfere. This is done in the beginning of the code on both modules at the line "const byte addr[6] = "00001";" Simply change "00001" to "00002" or a different number and the modules shouldn't interfere. Hope this helps!

Right now it can measure up to eight athletes, although I'm sure you could program it to measure 10. The only limitation is the LIDAR's range, since its maximum reading distance is 12m.

Hi Voon, I have not tested the battery life with a 9v battery, but it's lasted quite a while without needing a battery change. It shouldn't really matter whether you use a rechargeable battery or not.

I must have linked the wrong OLED screen :(. Good news though is that it should still work! The screen I used uses an interface called SPI, while your screen uses an interface called I2C. Both operate off of (pretty much) the same driver so you shouldn't have to do much modification to the code. All you need to do is change the way the screen is initialized, that is, the line that reads "Adafruit_SH1106 tft(OLED_MOSI, OLED_CLK, OLED_DC, OLED_RESET, OLED_CS);" Change it to something shown in a video showcasing how to use I2C OLED screens with Arduino like this one ( ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-_KD7skmusTQ.html&ab_channel=MissionCritical ) and it should work

@@CollinWentzien Thank you for the info. I will see if i get it working with this screen. If not I will try to get the one you used.

@@CollinWentzien Once again thank you. I'm going to give it a try. If now luck I will order a SPI OLED screen!

Hi Kim, the track timer is designed so that the "Counter" mode can detect multiple people in multiple lanes. The lane selection in settings acts as a "max" (for now). For example, if lane 6 is selected on the module, then all lanes 1-6 will be measured, but any past (7, 8) will be ignored.

@@CollinWentzien I see, noted, thank you so much for the information.

Hi Paco, I just replied to your email, but in short, do you know if the LIDAR works across the wireless connection or just the serial monitor?

Hi Collin, all resolved, works perfect. I love you !!! 😅

@@pacodiaz6696 Great to hear! What was the problem?

I think that when testing it in a small place inside the house it did not work well. I have tested the sensor outdoors and calibrated the LiDAR to ambient light and it was perfect. Thank you so much

At the moment, the track timer only displays the last time. You could add storing funcitonality either using an array list, or, if you want it to remember data even after a restart, using the built-in EEPROM.

@@CollinWentzienok thank you very much

Hi Kim, sorry for the late reply. I just responded to your other comment so hopefully that helps :)

The addresses are for different icons that are used throughout the system (left centered). I just make them in paint.net and convert them to hex files. By the beep sound I assume you mean the speaker, and to play tones on the speaker you use tone(pin, pitch, duration). More details here on how to use tone(): www.arduino.cc/reference/en/language/functions/advanced-io/tone/ Hope that helps!

@@CollinWentzien the icon do u mean for the oled display?

@@kimvuivoon4858 yes, they're the little 16x16 icons that you see in the menu systems

alright, thank you very much!

Yes, you must set the distance before you start the timer. And for different modes, the lane detection works slightly different. For both sprint and lap mode, the sensor only looks at a section of track, and when that section is crossed, the time stops. For counter mode, everything from the start of the sensor to the specified lane that is detected is recorded, but only the last time is actually displayed.

@@CollinWentzien thank you very much collin, it works now, the workable pin for nano is A4&A5.

I want this feature. It would be really good to see all the times. Kids are always asking. :)

How do I view the other times crossed@@CollinWentzien

Hi Joshua, I know Hackster says they're deleted but you should still be able to download them by clicking the download button for each file. Let me know if you have issues though

Ultrasonic sensor I mean

@@kimvuivoon4858 while it is possible, one of the benefits of using the LIDAR sensor is that it has a very narrow beam (around 2 degrees). The ultrasonic sensor, on the other hand, has a beam of around 15 degrees, making it better at detecting normal objects, but also makes the beam more spread out as the distance increases. The farther away a person is from the sensor, the quicker they cross it essentially.

Thanks and appreciate your reply

I don't see why not!

That should work, some libraries might not be too happy but it's definitely possible

I see, thank you very much for the info

Hi Kim. Most OLED displays either connect with 7/8 pins or 4 pins. Your screen uses a protocol called I2C, but it isn't very different from the way I set my screen up. I would suggest watching this (ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-_KD7skmusTQ.html&ab_channel=MissionCritical ) tutorial on how to set up the display. Let me know if you have any issues

I see, so do I need to edit ur code ? Once I uploaded ur code, nothing will display

It work well with the example code trying with library adafruit 1106 12IC

@@kimvuivoon4858 yes you will need to edit the code slightly. You should only really need to change things above setup() and in setup(), everything else should work fine.

Yes, of course! Arduino recently pushed out a new update for their Project Hub and for some reason my account no longer exists... I'll get in touch with them to figure out what happened. All the code, schematics, and files should still be available for download on Hackster (www.hackster.io/collin-w/easy-and-affordable-track-timing-system-dcc6f9 ), but if that doesn't work then let me know and I'll send you the files. Good luck on your build!

@@CollinWentzien thanks! got it now!

Hi Bob, All parts that I used can be found on my Arduino Create page (create.arduino.cc/projecthub/collin-w/easy-and-affordable-track-timing-system-dcc6f9 is the link). If you're interested in me building one for you, email me at collwentzi@gmail.com and we can figure something out. Thanks!

Hi Richard, feel free to email me or message me on instagram and we can figure something out.

Hi! You can reach me at collwentzi@gmail.com or my instagram @collin.wentzien

Thanks! I have included the fonts on my GitHub (github.com/CollinWentzien/track-timer/tree/main/fonts is the link). To add them to the project, drag both files into Arduino > Libraries > Adafruit GFX Library > Fonts. Hope that helps!

@@CollinWentzien i see, i have added it,. thank you so much!

Hi Kim, This error pops up whenever the sketch size is too large. Unedited, the code takes up about 95% of an Arduino Nano/UNO's flash, meaning you only have around 500 bytes of wiggle room (which isn't much). If you made any large changes to the code, it might just be too big to fit on the Arduino. I would suggest removing things in the code you don't need, such as maybe the muting speaker or some of the icons to free up storage.