Well, theoretically, that should work fine. But last year at states, we had to stop three of our matches for interference. Even though we had to ask to interrupt, we were able to prove it each time. Unfortunately, with a 2.4Ghz system there is no crystal to change, so the judge eventually just got fed up and banned us from asking to stop again .This year, the judges are allowed to pause the match if they see either of the bots experiencing radio interference, and the team is allowed to change their frequency.
Doesn't vex use 27 MHz?Did anyone else have trouble using 2.4 at states last year? We had some serious interference against Vex bots. Kind of a shame... we had the lamest Vexer take out our custom built bot last year.
Exactly! That's why we were so baffled. It was definitely the Vex bots, though. I built one for our C Team for invitationals, so we even did some testing outside of the competition. Within a minute or two of booting up the Vex microcontroller, our custom bot would start slowly drifting.That's really sad.Doesn't vex use 27 MHz?Did anyone else have trouble using 2.4 at states last year? We had some serious interference against Vex bots. Kind of a shame... we had the lamest Vexer take out our custom built bot last year.
And yes, it is very easy to get interference if you're using a 2.4 GHz set. I think there are some more expensive sets that can manage interference really well with frequency hopping, but I've never tried one.
Oh okay, I'm not up-to-speed on the different models of Vex. Either way, though, it's a narrowband system, and theoretically there's no way it would be interfering with 2.4GHz.1. Vex uses 75 MHz (the 27 MHz Vex kits cannot change frequencies and therefore can't be used in Sumo Bots). The more likely culprit of the interference with a 2.4 GHz system is the local WiFi network.
You'd think that would work perfectly, right? We were actually using this Spektrum transmitter, which does bind to the receiver. Sure enough, though, we were getting some serious interference, both at West Point and at home.2. The only way you can be assured that you won't experience interference with a 2.4 GHz system is to use one that binds the transmitter and receiver - once they are bound, the receiver will ignore signals from anything except the transmitter it is bound to, even if there are other devices using the exact same frequency.
Sorry if I was unclear, but I am extremely familiar with that page. Other bots at the state competition had been using 2.4GHz without problems, and my partner and I decided the advantages outweighed the risk. (Obviously, we were wrong.) I'm in no way blaming our event supervisor, and it's certainly not West Point's fault for having their WiFi on. It was just extremely frustrating to watch a Vex bot take out our custom bot due to interference.3. This is all explained on the web page referenced in the Sumo Bots rules (http://www.newyorkscioly.org/SOPages/Su ... ncies.html). The information regarding possible interference on 2.4 GHz has been posted for two years. Students need to read the rules, including any web pages referenced by the rules. Keep in mind that no school or college will turn off their WiFi network just so a robot competition can be held, so selecting to use a 2.4 GHz transmitter/receiver that do not bind together is "at your own risk". The judges will do everything possible to eliminate interference, but there are some things out of their control, and the entire tournament cannot be held up because one bout has to be restarted over and over again because a team decided to risk using a transmitter/receiver pair that are not bound together.
Exactly. We obviously restarted the bot each match, and did the same whenever we stopped for interference. Yet no matter what, after half a minute, we'd start to have interference again. So with all due respect, I really don't think our issues resulted from not reading the rules carefully enough.4. Many of the bots at both the C Division and B Division State tournaments last year used 2.4 GHz, and this is the only incident I am aware of where there was interference with that frequency that could not be resolved by restarting the transmitter and the bot (same holds true for the National competition last year).
I can't quite decipher Spektrum's website, but I think the DX5e has full-range DSM2 as well. I think we're stuck with our DX5e if we stay with 2.4GHz, though--the DX6i is just too similar to warrant an upgrade, and anything more powerful is overkill for sumobots.I am into RC helicopters and have the Spektrum DX6i 2.4GHz transmitter and have never had any interference problem flying near wifi, cars, phones, and power lines... I don't know for sure if it's better than the DX5e but it seems interference free. In terms of quality though the DX6i is a heck of a lot better and has full range 2.4GHz DSM2.
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