Solution for field time display wanted

Just FYI, when you’re looking for cheap cables (HDMI, VGA, USB, etc etc), I can’t say enough good things about Monoprice. I’ve gotten a bunch of stuff from them and it’s always been great.

They have a 50’ VGA cable for $13:

Their prices are almost unbelievable, but the products work. I have a 75’ HDMI cable from them that works great (and we’ll be using it at our VEX event in 2 weeks).

As for the rest of your list, can’t help much there other than to echo Rick Tyler’s comment about borrowing… every event I’ve been involved with has just borrowed monitors (even the World Championship), either personal ones for from work. If you can’t get your hands on a loaner for a weekend then I guess the next place I’d look would be on eBay or Craigslist or something for an old laptop or even a desktop PC. And there’s no requirement for an LCD either - a tube monitor could be placed on a short stand near a field and work fine. I’ve seen monitors like that being given away a lot lately.

As far as custom solutions, I’ve have 4 of these sitting on my workbench for a couple years:
My goal was to design a driver board with an XBee for wireless connection to a laptop for timing (though certainly a serial connection would work too), but I haven’t pursued it much further since it would probably be difficult to make such a timer for much less than $50. Also, it seemed to me to be getting easier every year to find laptops to borrow for field displays to the point where it wasn’t worth it, especially when you factor in that the field displays can provide other information that would not be available on a 7-segment timer.

Reading all the different viewpoints in this thread, I am once again reminded that there are at least two types of people in the world.

This thread might be evidence that there are at least five types.


The first 3-4 times I borrowed flat panels, big TVs and laptops from work it was kind-of cool. The next 10 have simply been a giant chore every time. Hauling those big (and bigger) boxes around; carrying heavy, slippery laptops; constantly worrying about damage in transit and during the event; constantly worrying about what folks might install or reconfigure when I wasn’t looking; getting permission to do it; gathering up all of the equipment; etc.

Offer me a lightweight, thin/compact, and inexpensive appliance that is sturdy enough and small enough for 3 or 4 to be packed in an empty printer-paper box, and I’ll call the modest cost money well spent.

My recent attempt at satisfying my own request was buying a bunch of refurb’ed NetBooks for $200 apiece. Not exactly chump change, but inexpensive enough that losing one or two won’t be the end of the world. However, to really be effective they will need an external monitor. I’m going to try living with just the small Netbook screen, but I know I’ll be annoyed by its size.

PS: Any time tournament prep gets too hard, I definitely fall back on using the wet-ware approach Mike_from_Cambie brought up. You can do wonders with a stopwatch, a loud voice, and a couple of whiteboards.


Well then, I’ll offer the way we really do it – we use one of the school’s LCD projectors and display the time on a screen that the school has in the gym. The drive team coaches then turn their heads to see the time remaining. Cost - $free, simplicity - nearly infinite. And I don’t have to store any of it until next time. I personally don’t like putting anything in between the audience and the game, so I don’t put monitors on the field wall. The only time I’ve done that was when I was helping with someone else’s event.

after reading the new posts and thinking, i realize that if the field controller were to alert drivers in regards to time elapsed or time reamaning (i hope we all can do math to find the other) would make a world of difference for drives and coaches playing the game. is this possible with the field software?

Having been at the event in Downingtown last week, I can agree that the screen configuration was nowhere near sufficient. People crave data in situations like this, and unfortunately there wasn’t enough.

The key to having displays really is just using school equipment. A pair of projectors - one for each “division” would have drastically simplified things. As it was, by about the thirtieth match, my mother (your HS scorekeeper) was thoroughly annoyed rotating the one monitor between the two fields. School equipment or not, I remember seeing Steve’s netbook wandering around the room. That netbook, and it’s VGA output, could have been used much better.

For the event at Delaware County Christian School in October, we ended up running 6 laptops and three projectors - all belonging to the school - for a total of 7 public displays. Also, one of the computers was dedicated to the more mundane tasks, such as printing, to avoid interference with the tournament in progress.

As to the suggestions of building a timer, I can conclusively say that such a device would not be supported by the Tournament Manager Software. The closest you could get would involve writing a locally-hosted web-app that reads data sent via the Web Publishing feature, however that system does not include match timing data anyway, so it still wouldn’t work. Short of decompiling the program or using a microcontroller as suggested previously, there’s no way to integrate a custom-built countdown with the Tournament Software. Just ask your school’s IT folks for the most basic thing with a screen and a network card.

As to inverting the countdown, No, the software cannot do that. It is simple math, but the program is given as-is, and is meant to stay as-is. Besides, experienced drive teams are used to planning their end games based on a clock that counts down. I imagine the confusion could cause people enough aggravation to lose, and thus enough anger to make your event unfortunate.

Thanks for the reply and say “Thank You” again to your mother for helping out. Our parent volunteers make things work.

Your key phrase is “using school equipment” and asking “the schools IT folks” for items does not work for us. Downingtown Area Robotics is not an official school club, there are not any teachers involved in an official capacity in either the 105 roboteer VEX group, or the 35 roboteer FRC group. We are all parents of roboteers or in the case of Steve and I, deranged believers in competition robotics being good for students (we don’t have roboteers in the program) .

We rent the school, we rent the custodial services. So there isn’t school equipment to use. When the VEX year started we had 50 roboteers and 8 robots, with plans to buy netbooks. When the school year started we had an influx of 50 more roboteers (105 total) and decided to field 7 more robots than buy computers. If we had $2000 we would buy netbooks for the roboteers to program on.

The request for a countdown counter was based on my experience with electronics (Hi I’m K3FXS) and I’m looking for something that I can mount on the fiellds. Netbooks don’t work, you need to drag ethernet cables and power to the field (TM and wireless are not happy mates). A monitor is fine, the USB idea works, but it also needs a VGA cable and power.

A battery powered, LED/LCD display that uses the field controls for signals is the best option. The field knows when it’s in Auto and Driver modes.

In my case STEMRobotics drag the fields to 7 events a year in our area. We don’t charge for doing that and we volunteer our time. (With a little luck I’ll put in 2000 hours in calendar year 2010) Paying $1600 for displays isn’t how I want to spend STEMRobotics money when I can use that to start 3 more teams. What I want is a $45 display that does the same thing.

So put on your EE design caps, pull out your Digikey catalog, fire up your irons and design and build countdown clocks. There is a small market of 500 that you can sell. I’ll take the first 6 at $45 each. I bet the other teams that have fields will snap the rest up for practice sessions and their events.


(I need to add in the spirit of full disclosure that while we are not an offical club, the Downingtown School Board, on the recommendation of the Superintendent, have given us a 1 year lease on 17,000 sq ft of office/warehouse space to build robots in. So I’m not going to go back and whine about needing $2000 more for timer displays. )

I did not know that about your program. In the future, let me know ahead of time, and I can bring a machine or two of my own, plus possibly a few from DC.

Next events are:

Dockbots 11

Souderton Vexperiment

Eastern PA regional

And the first event of the new year. Bridgewater has been the host of this in years past, but Radnor has put their hand up for a new event, so there may be two in May.

The Philadelphia region offers more VRC events (12) vs FTC (2). Our teams with their cooperation of bringing other schools into their alliances means that more of our area teams will compete at the worlds. Our concept of “You are already qualified, help someone else qualify” is paying off. Through 4 events, over 15 unique teams are going to worlds. We are looking forward to our Power Teams signing up new teams, your (DC Knights) teams pulling new teams and even teams like “The Joneses” (677), tossing away “winning is most important” away to take on the “everyone goes to Disney” plan.

While China and New Zealand will be the most represented, I want to see Philly teams at Disney. I want to stand next to Rick TYler and Blake at Worlds and go “Hey, are we making a difference?” and get nods and smiles back.

DC Knights have gone from “who?” to “Whoooooo!” in a very short time, you guys rock.

But I still want my $45 display :rolleyes:

The DC teams (and thus, my computers and I) will not be at Abington. (Our formal Christmas Banquet is the night before.) I can’t speak on events after worlds, as I’ll be busy with things like graduating, but we’re currently planning on the other events you listed.

Sorry I’m late!

I’m partial to Atmel’s rather than PICs. I’d probably build something with the Arduino bootloader for easy hacking.

So, what are the specs?
*]Four 2¼" Tall digits ok?

*]Battery powered (standard Vex batteries)
*]How much runtime between battery changes?

*]Programmable presets and modes (up/down, MM:SS, M:SS.S, SSS.S, etc…)

*]What additional indicators? (e.g., Auto -vs- Driver)

*]How critical is wireless (probably the most expensive feature)

  • Dean

My thoughts (ready to be combined with a few more sources to create a good spec) Maybe we need a spreadsheet where candidate features are listed and each ordinary voter gets to vote for no more than half the features. Voters willing to pre-order the devices get extra votes. :slight_smile:

Time Display

  • Digit size = I’m thinking of 6" (4" minimum)
  • Digit brightness - Visible in full, direct sunlight (coming into a building through a window, or at a county fair outdoor exhibit).
  • Digit count = 3 places that show seconds is fine. Minutes or fractions of a second aren’t very exciting to me. 999 sec > 15 minutes. Adding a 4th digit would give you 150 minutes (enough for lunch breaks).

Power = AC Power if necessary, but getting rid of the need to run a power cord out to each field would be a definite bonus. Perhaps some sort of Power-Over-Ethernet would be sexy, so long as there was “no” chance of damaging equipment that uses similar connectors (when the cables get swapped up). Maybe Power-(and Control-Signals)-Over-Phone cord? Battery Power sounds OK but might be at odds with some of my other desires.

  • POE, or my POPC, would still require a computer or some similar device as the energy source. Maybe Battery or AC power are the two right choices after all.

Function = Being able to interpret (perhaps with human assistance in unusual (Field Reset) circumstances) the Tournament Manager signals is important but not absolutely required by me.

  • Using about 4 discrete lines to create a reference and 3 bits of commands would probably be perfectly adequate.
    – A few year ago a PC-based serial interface would be a good way for a serious hacker to control one of these. It might still be the way for a Vex microcontroller to control one (those Vex microcontrollers are certainly more expensive than the bare PICs and Atmels; but they are plentiful at a VRC tournament and they can be reprogrammed/patched/upgraded using skills and equipment that is also plentiful at a VRC tournament or club meeting).
    – I’m guessing that some sort of USB-to-“discretes” is the current favorite for connecting appliances to computers now.
  • Countdown is far more important than Count up.
  • Plugging into the 5th or 6th ports on a Field Controller’s Player plug-in tower (thoroughly isolated to prevent interference) would be very nice (until VRC creates a 6-player game (then we would need a splitter)).
  • Operating when the field is controlled only by a manual switch (no computer, no TM), and in that circumstance becoming the field controller (enabling disabling transmitters) is very important to me.
    – This request makes me a requirements creep; but field control and a time display that a ref can activate and reset using nothing more complicated than 3-4 built-in buttons (or a VEXNet switch) means 100% independence from the complications that often encrust running exhibits and tournament fields. This is really, really attractive to me.

Other User-interactions:

  • Auto vs Driver seems unimportant during the countdown, but would be useful to see before the countdown starts to ensure you launch the correct timer.
  • I kind-of like the thermometer indicator for time as a supplement to the digits; but I predict that the digits are far more useful.
    – I can imagine that a thermometer (or Cylon eye) capability could be used along with automated scoring to show scores, or show score differences. But the scoring-possibilities are pretty unimportant right now.
  • Playing a sound a specific times, or at intervals, or both would be useful. Beeps that grow more frequent as the countdown get closer to 0 come to mind.

Mounting & other physical:

  • Be able to bolt onto existing VRC field panels (including the 8’ x 8’ fields made for the TSA competition). Be able to easily bolt onto a stick of 80/20 brand extruded aluminum
  • Be able to easily bolt on (or replace) a piece of Polycarb protecting the device from clumsy robots.


Why not run a program that calls out the time every 5 seconds? It would be easy to implement and free. Just run the program on the same computer the competion controller is running on.

If you actually mean “calls out” as in audio that would be obnoxious. Especially when you consider that the time it takes to say “One minute, fifty five seconds” could take as long as 2 - 2.5 seconds i feel like the beginning part of the match would get a bit crazy.

In my opinion a visual display is a better option, although possibly more expensive. With a visual display drivers and coaches can take a look when they want.


Wow, there is a lot there. I’ll address a few of these ideas while I consider some others.

  1. Display size: Bigger displays cost a lot more (like 4x) - not just because they cost more, but because they require more PCB space, and they draw more power which complicates the power situation. I think 4" might be just possible at the $45 price point. 5" displays would probably blow past this into the $60 range. I’m not sure about 6" displays, but I suspect discrete LEDs would become more cost effective and would land in the $90 range. As size goes up, the PCB becomes the most expensive component (by far).

  2. Power: I don’t think POE makes sense unless we are using ethernet as the communication protocol - I believe it requires some negotiation that would significantly complicate the design. I figured a simple on-board switching regulator that could run on anything from 5V to 24V, AC or DC. This would allow the use of batteries or wall warts.

  3. Wired control: I think serial would be the best way to go because it is compatible with just about everything. As for USB, FTDI seems to have cornered the hacker market for USB->serial interfaces, so that provides a handy USB option. Additional inputs could be provided for hard-wired signals such as trigger buttons or even photo-interruptors (say, if you were trying to time a race). I don’t know anything about the Field Controller protocols, so I’ll have to do a bit of research to figure out compatibility with that. Oh, no reason power couldn’t be carried over the serial cable, though USB doesn’t deliver enough current to run one of these displays (remember, you want to see it in well-lit places).

  4. Wireless control: Perhaps a 4P4C modular jack could be provided so that you could plug in a Vex 75MHz receiver. Then a Vex transmitter could be used to select presets, and start/stop the clock. You’d have to reserve one frequency at the competition (or rule out the use of 75MHz altogether). Alternatively, any of the widely available wireless serial links could be used on the serial port to provide all the flexibility of wired control without the wires.

Thats about it for now … I’ll keep thinking about it, and try to find some details on the Field Controller.


  • Dean

After giving it much though I’ve decided that I want a simpler version.

I’m really not up for dragging yet more cables to the fields.

I think the 8 conductor cable from the control system knows when it’s autonomous mode and driver mode.

So I’d like something that I can plug the field control cable into and then a cable that runs to the VEXNet / Transmitter splitter. Or into the third team slot, but I think that’s gone off the new field controls. I’d be happy to mount the timer display on the top of the towers (so teams can look down and see the time), or on the field side of the tower so they can look across at the display. So I’m in for 2 displays for each field to not have to drag extra cables.

So my requirements are:
a 3 digit display to show M:SS. A four digit display works if they are cheaper, but it needs to fit on the tower. I’m also good with Blakes suggestion of just seconds (ie: 120 for 2 minutes) When the field is off the lights can be off. Need some way to set the autonomus and driver times. I’d like to get 1/2 day of events on a 7.2v 3000mh battery charge.

I want the displays to count down from 2:00 to zero and :20 to zero. A bonus would be they flash zero for a few seconds before they turn off (because the field went off).

Quazar, I have a field control that I don’t need until 15 January, if you want to PM me a mail address I’ll send it to you to play with.

The way the field control software is written, your only practical way to connect is the field control system. The box on top of the tower indicates mode by connecting certain lines together:

For the VexNet competition connections (cat5 - 8 pins), pins 1, 4 and 7 serve as ground. When pin 2 is connected to that same ground, it indicates Autonomous. Also, when pin 2 is not connected, it indicates driver control. When pin 3 is connected to that same ground, the robots are fully disabled. When pin 3 is not grounded, the robots are function as determined by pin 2.

I don’t remember (or have) the diagrams for the crystal-style competition connections, but it’s something like connecting pin 2 to pin 3 or 4.

I would still prefer the varied content LCDs can provide, but in the direction this thread has swayed, I would vote for simplicity: a vex microcontroller with a 3- or 4- digit display.

Keep in mind, if anything goes wrong with field control, the disadvantaged team will point at your non-official countdowns and whine. Besides, if you’re spending $45 each on two displays per field… eBay has netbooks for less than that.

Last year, at our competition, we simply used a projector. All you need is a VGA splitter. Connect the projector to the computer that is running the competition.This eliminates the need for long power cords and things like that. Just set up the projector right next to the control station, and shine it on the wall next to the competions that are going on. It can easily be turned to face different positions. If there are two matches going on, I’m sure somebody or some school will be willing to lend a projector. They’e not that expensive either.

I think you are making a mistaken assumption that all users will only want to use this hypthetical device as a passive attachment to the current field control software and circuits.

Attaching it to the current system (at the drivers station control signals or elsewhere) will be an important use for it, but not necessarily the only use. Particularly if it is an alternative to that current system.

A few pushbuttons, a two-value countdown clock, simple connections to the drivers stations, a power source - In some situations, that might be a $50 replacement for a lot of unnecessary baggage.


I understand your assertion/opinion, but if you read through the earlier messages, you will see why some folks disagree with it.


Agreed - I’m doing some wishing; and I’m expecting a good core suite of functions to emerge after I and a few others combine our wishes, and then mix in some reality.