Cheap-ish timer (getting more polished)

DIY timing systems
Post Reply
jpswensen
Merchant
Merchant
Posts: 16
Joined: Fri Nov 14, 2008 7:11 am
Location: Pullman, WA
Contact:

Cheap-ish timer (getting more polished)

Post by jpswensen » Thu Mar 15, 2018 9:27 am

I see there are plenty of people who have made DIY timers, so maybe this is redundant. Our pack recently got a nice new extruded aluminum track, but didn't want to spend the money on a timer that year. So, being a roboticist and tinkerer I decided to build them one. I am still working on polishing the documentation, making an official PCB design, publishing the 3D printed parts for various tracks, etc., but it has now worked for 4 races without a single problem.

We basically don't have a LED finish line, but project the GUI up onto the wall with a projector.

Currently everything we have is at
https://github.com/jpswensen/SunnysidePWDTimer

The (really bad) documentation is at
https://github.com/jpswensen/SunnysideP ... umentation

Future plans:
1) Handle more than 4 lanes
2) Use the WIFI capabilities of the microcontroller to not have to plug in over USB
3) Handle heats, dens, etc.

Edit: As opposed to our video, we have no plans of ever charging for this.
Last edited by jpswensen on Tue Mar 29, 2022 11:05 pm, edited 1 time in total.



User avatar
Vitamin K
Pine Head Legend
Pine Head Legend
Posts: 1161
Joined: Sat Apr 20, 2013 7:26 pm
Location: Spotsylvania, VA
Contact:

Re: Cheap (still unpolished) timer

Post by Vitamin K » Fri Mar 16, 2018 2:01 pm

This is pretty cool! Where in the docs would I see the assembly schematic?



jpswensen
Merchant
Merchant
Posts: 16
Joined: Fri Nov 14, 2008 7:11 am
Location: Pullman, WA
Contact:

Re: Cheap-ish timer (getting more polished)

Post by jpswensen » Tue Mar 29, 2022 11:29 pm

Finally getting back around to working on this more. Here are some of the high level updates.
  1. Updated from the ESP8266 to the ESP32. The ESP32 has two CPU cores, so one core is dedicated completely to capturing super accurate timing and the other handles all the communications with the timers software
  2. Changed from using C++ for the timer GUI to using Python (the code on the microcontroller is still C/C++). I also re-vamped my simple timer software to allow groups (this is the part I am still working on a bit)
  3. Finished a full PCB design that anyone with some pretty rudimentary soldering skills can put together. The board can handle up to 8 lanes, but the software lets you pick however many lanes you want. Th full timer cost is about $50.
  4. Also, since the software is so simple, If you were trying to make a 1-2 lane track at home, you could forgo the printed circuit board and just buy the microcontroller and the sensors and a switch for the start gate. Which means you could have a drop dead simple home timer for about $25.
  5. you can either connect to the timer via USB/serial, or it starts up as an access point and you can either just connect wirelessly to the timer itself or you can tell the timer to connect to a local wifi access point and then access it that way. It uses mDNS to respond, so you can hit it with just the domain name of "pwdtimer.local".
    [/lis]

    You can see some updated photos of the timer and the current state of the software here

    https://imgur.com/a/ZSKn7g1

    Here is a bad copy/paste from the Excel spreadsheet with the complete parts list. I will be uploading this to the github repository.

    Item Source URL Price Qty Ea Notes
    Printed Circuit Board Oshpark https://oshpark.com/ 15.133 1 15.133 Must buy 3
    ESP32 Dev board Amazon https://www.amazon.com/dp/B08MQ647ZG?ps ... ct_details 6.4 1 6.4 Link is pack of 5
    JST connector kit Amazon https://www.amazon.com/dp/B01MCZE2HM?ps ... ct_details 11.99 1 11.99
    IR emitter/detector Amazon https://www.amazon.com/dp/B01I57HIJ0?ps ... ct_details 9.59 1 9.59
    JST 3-pin connector Digikey https://www.digikey.com/en/products/det ... TR/9830388 0.099 16 1.584
    JST 2-pint connector Digikey https://www.digikey.com/en/products/det ... TR/9830318 0.1 1 0.1
    3.3V regulator Digikey https://www.digikey.com/en/products/det ... V33/586012 0.76 1 0.76
    0.1uF capacitor Digikey https://www.digikey.com/en/products/det ... DD/2539218 0.26 1 0.26
    10uF capacitor Digikey https://www.digikey.com/en/products/det ... 3M/5410631 0.22 1 0.22
    Terminal headers 0.1in - 19 pins Digikey https://www.digikey.com/en/products/det ... -RC/810157 1.17 2 2.34

    48.377 TOTAL

    So, I still have a bit of work left to do, but found a few nights and weekends to work on it and think it should easily be wrapped up by next racing season.



Post Reply

Who is online

Users browsing this forum: No registered users and 1 guest