General rules (2017)

Please read these rules thoroughly. Some rules have changed since last year.

  1. All robots must have an operational Raspberry Pi at their core which carries out the majority of the computing effort.
  2. Other boards, such as an Arduino or other microcontroller, may be used on the robot but the Pi must be in overall control.
  3. An additional piece of equipment e.g. a games controller, a laptop, mobile phone or tablet may be used to control the robot, but must not be physically attached.
  4. All robots must be powered by batteries and must not require mains power for anything except charging battery packs.
  5. No airborne robots are permitted, e.g. drones. Walking and self-balancing robots are permitted.
  6. The main chassis, including wheels and protrusions, of competing robots must fit within a 225mm x 300mm footprint (but see the note on attachments below which allows for slightly more length)
    1. The maximum width of the robot as it drives forward should be 225mm.
    2. The maximum length of the robot as it drives forward should be 300mm (but see 7.2 below for additional length).
  7. It is permitted to add and remove components from your robot during the course of the competition in order to tailor it to individual challenges.
    1. The basic chassis, Pi and controller arrangement should remain the same.
    2. The attachments must not add more than 225mm x 100mm to the robot. The maximum size of the robot with attachments can, therefore, be 225mm x 400mm.
    3. Please see the diagram below for an illustration of robot sizing.
  8. There will be a number of different challenges into which you may enter your robot, the results of which will contribute to an overall score. Points structures will be published by Pi Wars to ensure that teams are aware of how many points each challenge is potentially worth.
  9. None of the challenges are mandatory.
  10. No points will be earned from challenges not entered.
  11. There may be some physical requirements for specific challenges – please consult the individual challenge pages for more information.
  12. Robots will be allocated to a category based on the team that constructed them. The categories are as follows:
    1. Schools and other kids clubs.
    2. Beginner roboteers.
    3. Intermediate roboteers.
    4. Advanced/Professional roboteers.
  13. Teams will be asked at the time of application into which category they should be entered. The final decision on category rests with Pi Wars in consultation with the robot team.
  14. Robots will compete and be ranked against other robots in the same category.
  15. Under-18 competitors will need to be accompanied by a responsible adult.
  16. If LiPo batteries are used, any charging must be done inside a fire-proof bag, available from many places that stock the batteries, such as HobbyKing. This is to ensure we don’t have any accidents.

31 thoughts on “General rules (2017)

  1. The maximum attachment size of 80mm does not seem wide enough to allow a skittles ball launcher to be attached. the skittles ball is 74.3mm diameter, this leaves something like 2.8mm each side of the ball for guidance. Can this 80mm be increased to say 100mm.

  2. Just to clarify the size limits, do the maximum robot dimensions (210×297) include the optional ‘attachments’ or could your basic chassis be 210×297 with an extra 210 x 100 allowed for the attachments, effectively allowing the robot to be extended beyond the A4 footprint?

    1. I think we’d envisaged it being in front of or behind the robot (hence the longer measurement is A4 width), but I think we’re fairly flexible on where the attachment can be. 🙂

  3. New dimensions noted. Can the width of the attachment also be altered to make it 100 x 225mm?

    Please can we have an assurance that critical things like dimensions will be ‘sealed in stone’ from the point at which entries are confirmed (1/10/16)? I’m asking because we will need as much width as we can get and I wouldn’t welcome a redesign if it changed again because a commercial chassis was, say, 230mm wide! #scratchbuiltismorefun 😉

    1. Hey Andy.
      Yep, changed the attachment width too. Good spot.
      I can give the assurance you’re looking for right now. Yes, those things will be set in stone.
      I also agree with the hashtag 😉


  4. There appears to be no height restriction, is that correct ?
    I’m thinking a high tower, leading to a curved ramp, and a mechanism to take the ball to the top of the tower and use gravity assist to give it speed down and ultimately towards the pins.
    That could be achieved without extending a robot’s footprint at all.

    1. Nope. No height restriction. There are no obstacles, for example, that require you to limbo 🙂 Inventiveness encouraged 🙂

  5. Your answer to Mike on rule 6 implies that being A4 PLUS attachment can result in violating rule 7.2 with the length increasing to 400mm or even 525mm with an unconventional arrangement of the attachment.

    1. Ah. Yes. You’re exactly right. I’ve re-ordered the rules and linked them together. Basically, you can add a rectangular block of attachments to the maximum length. It’s now explained properly in 6 & 7. Thanks for pointing out the discrepancy.

  6. With regards to rule 6.1 “The maximum width of the robot as it drives forward should be 225mm.”

    If you have a robot which can drive in any direction, such as the two robots with omniwheels that competed in PiWars 2015, this rule would suggest that the robot must not be larger than 225mm in either width or length. Is this your interpretation of this rule or would the robot still be allowed to be A4 shaped?

    1. Good point. In that case, the robot would still need to fit in the area of 225mm x 300mm. That’s the restriction to be aware of, so no 300 x 300 robots 😉

  7. I was going to ask on the Challenges page but there isn’t a comment box, does code need to be submitted this year and if so is it the same procedure as 2015?

    1. Not this year, no. We’ve decided to ‘rest’ that challenge. It was proving to be something that needed to be done at exactly the wrong time.

  8. Question with respect to rule 7.1 “The basic chassis, Pi and controller arrangement should remain the same.” – My son would like to change the wheels depending on the challenge. Do they count as part of the basic chassis? I’m leaning towards them being so, so that he’ll have to choose one particular set of wheels for all challenges. What do you say?

    1. Hi Emma! We’re not counting the wheels as part of the basic chassis as, generally, wheels are detachable. So, yes, he can change them depending on the challenge 🙂 By the way, if you don’t have any luck with the controller, I recommend the Afterglow PS3 controller. Get hold of one if you can – Brian Corteil (@CannonFodder) will be able to help you with code to get it working.

      1. Many thanks Brian. Looks like someone is donating a genuine PS3 controller to us, so we’ll try that out first. Hopefully it’ll arrive before we attend our local Raspberry Jam on Saturday, so we can work on it then. Otherwise there are always the autonomous challenges to get going on 🙂

  9. Hi Mike. We’ve now settled on LiPo batteries for our robot. Reading round the subject, it is clear that they must be treated with care. I’ve just purchased a fire-proof bag to charge them in. Can I suggest that we add a rule that any team using LIPo batteries MUST use a fire-proof bag when charging them at the venue. Hopefully it goes without saying and those we saw last year with LiPos were taking that side of things very seriously.
    On a similar subject, will there be rules about the use of soldering irons at the venue?

    1. Funny you should mention that, I’ve just got into LiPos myself. Frankly, if you ever read the instructions and followed them you would never use them! I will send out a message on the next update. Soldering – we’re waiting to hear whether we can use the second floor where there’s a soldering station with extractor.

    2. +1 for the LiPo rule. Also, maybe it is worth mentioning/trying to embed in rules – if nothing else as a soft rule that LiPos shouldn’t be exposed on the outside of the robots. They should really be inside of the robot, not strapped on the outside (as it is currently the case with ours). That way there won’t be chance for accidental puncture of one during Pi Noon challenge.

      Further to it, as a precaution we’ve added a fuse (used cheap Hobby King’s ‘boom stopper’) directly after the battery. That way we are protecting battery against accidental short (and LiPos do not want to be shorted either).

  10. Can I have attachments which are larger than 100mm in length as long as the robot stays within 225mm * 400mm ?

  11. “An additional piece of equipment e.g. a games controller, a laptop, mobile phone or tablet may be used to control the robot”.
    To my mind, this is then no longer a robot but a remote controlled vehicle. Is there a category for autonomous robots, i.e. machines
    controlled solely by programmed actions?

    1. To our minds, it _is_ a robot, regardless of whether it’s autonomous or not. We design the courses so that there is a split between those that are expected to be completed by remote control, and those that _must_ be completed autonomously. There is nothing to say, however, that someone can’t come along with a fully-autonomous robot on the day and attempt all the courses in that fashion. In fact, we have someone this year who may try that. There is no separate category for full-auto robots.

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