Hello, I have a robot which uses a hitec laser 4 controller to operate it. The range I can get is only 100ft. I am also going to attach a 4 DOF arm to my robot which will use a madcats PS2 controller to operate at 40 ft. Is it possible to boost my signal further for both the arm and the robot past to what I have now. This robot was built as a surveillance robot for the sciencefair and more range is needed to make this a practical robot for its job.
Any help would be greatly appreciated, as I am only 15.
If you think your signal is actually weaker than it should be, you might want to try soldering a capacitor across the terminals of your drive motors.
I’ve heard that motors can cause quite a bit of interference.
I’m not sure how to boost signals…
Please hold, someone who knows what he’s talking about will be with you shortly (I hope )…
thanks, becuase i do need a large amount of range for my robot. A few people at the science fair had 2 km of range! Im not sure how this was done, though I’m sure it wasn’t done with regular RC reciever or the hitec kind we use. Hopefully I can actually get more range on my robot some how.
What type of “wireless” scheme are using? Are you using something that’s IR(infrared)-based or RF(Radio Frequency)-based transmitter/receiver?
IR and some RF transmitter/receivers are line-of-sight kind of thing, if you don’t have a good line-of-sight between the two, it won’t work.
Many RF transmitter/receivers will work without line of sight, but it depends on what you’re working around. Higher-frequency transmitters/receivers usually are more sensitive to this, as higher the frequency, the more “line-of-sight” you have to make the transmitter and receiver in order for it to operate. Lower frequency usually propagates better, but the difference is really on what type of terrain/object your’e tring to overcome. If you’re operating on flat land with no obstruction, all transmissions are basically line of sight, if you’re planning on operating the robot around hills, inside enclosed boxes (say in air ducts), line-of-sight are not an option.
Unfortunately, most, if not all the RF-based controllers that are made for video game consoles like the PS2, gamecube, or the xbox, has a very limited range and also uses the 2.4GHz carrier frequency. The transmitter (controller) were never originally designed for you operate it anywhere outside the line of sight of the receiver. The best way IMO to operate it wirelessly is to buy a nice 12+ channel receiver/transmitter (radio) like the one they use in R/C airplanes and tanks, and tie each channel on the receiver into a microcontroller and map it to a certain sequence of servo movement.
A suprisingly large range in a suprisingly small package.
I’m sitting right now in one corner of the house and getting 3 bars with the robot about 40 feet away, with at least four walls in between (and, the robot moves when I press buttons, so I know it’s not a fake 3 bars).
I haven’t yet bothered to do a full line-of-sight test, though.
I suspect it’ll be at least 100ft.
not sure, they were college students (student college that is). I have good range with my hitek, but the range of a madcatz sucks for the application I need my robot to persue.
Do you know what wireless setup they were using? 2km with a PS2 wireless controller is probably a bold faced lie unless the put incredibly strong, low noise, bidirectional amps inside the controller and it’s base. This is both hard to do without making the thing weigh a ton (batteries, boards, antennas, etc.), and spending an insane amount of money. Even with the best parts, 2km would probably be an exaggeration or only true under a best cases scenarios (line of site, good weather).
2km with WiFi is believable. A $200 slotted waveguide antenna can get you great range (omnidirectional too) even under poor conditions such as bad weather or multi-story buildings inbetween. trevormarshall.com/waveguides.htm has plans, background, and a link for purchase, as well as info. for two that got 7km range in Australia (top of page). If you put a small 6 dB antenna (8") on a bot with a WiPort and used a 15+ dB antenna like the one linked above on the base, I could imagine 2km range easily with a normal WiFi card. There are high power (500mW) cards that coupled with a strong antenna give good range. Directionals like a cantenna can get great range too, however you’d need some mechanism for keeping the base pointed at the bot. That’s not too hard, just need a few servos and a little programing skill, see smithstuff.net/steercan/Steercan.htm for ideas. I could imagine them making a similar base station like, probably a lot of people here could whip something like that up for less than $100 if so inclined.
As far as increasing your range. My guess is you should try a better antenna(s) before looking into amps. When I was your age (I feel so old ), I hooked up a $24 TV antenna to my Intel wireless peripheral series basestation (did nothing to the gamepads, mouse, or keyboard) and boosted the range of the peripherals from about 15ft to more than 100ft. This was a 900 Mhz system. If you can easily find the length of wire your controller uses for an antenna, you might want to play around with different antennas (and connecting them through shielded coax wire). It would make your controller a pit more of a pain, since you’d probably need to teather it to a small base where the larger antenna lived. However, if the idea is that the bot moves around while the user sits at a station or something, that wouldn’t be so much of a problem. You also wouldn’t need to mod any electronics or the part on the bot. However, a slightly larger antenna (think a 6 dB one sold for inscreasing WiFi range) would probably help here too.
If you could confirm that your setup is working at 2.4 Ghz (as opposed to 900 Mhz), you might want to look into a Hawking bi-directional amp. It’s the only 2.4 bidirectional commercially sold for a reasonable price ($60) that I know of. Don’t expect it to help than much, say only a 40% boost in range.
ok thanks. BTW I think the college students used some sort of GPS system or Wifi via to a computer. Thanks for your help. Maybe these antennas will boost my signal a bit more.
I checked online and the Mad Catz is 2.4 Ghz so WiFi stuff should work. The HiTec Laser 4 is a 75 Mhz devive. 75 Mhz antennas are very expensive for all but the 2 dB ones (like the pullout you’re probably already using). Check hobby RC flight stores for that. I’m sorry I’m not experienced enough in that area, so I can’t help too much.
Those 2.4 Ghz yagis you linked to would work well, but you’d have to deal with directionality. The little ones might, but my opinion is that they’re a rip off. None state the dB rating of the antenna clearly. My guess is they are in the 1.5-3.0 dB range, i.e. they don’t give you much boost if any compared to the what you have (probably just bent pieces of wire) . Zoomkat is right that its often easy/ cheaper and often gives better results to build your own. Search the web, there are plenty of sites about making WiFi antennas. Cantennas, yagis, reflectors, biquads, even some simplier omnidirectional types can be built basically out of junk, some cable, and a plug.
If you must buy, check out eBay. They have nice 9 dB antennas (15" used in Linksys eq.) for sale dirt cheap. They’re verticle colinear omnidirectionals and while I believe they’re overrated, they should actually give you a good boost. The 7 dB ones that are flat are actually mini-slotted waveguides (they use traces on a PCB as slots). I have one and it works fairly well. 5.5 dB is probably a more accurate rating, for my equipment at least. If you could put a 15" on the PS2 controller, and the 7dB on the bot, you’d boost the range a good number of times. If you can manage to fit a 15" Linksys on the bot too (you get two in the kit meant for a router) that should handle your PS2 controller issue for sure.
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), I hooked up a $24 TV antenna to my Intel wireless peripheral series basestation (did nothing to the gamepads, mouse, or keyboard) and boosted the range of the peripherals from about 15ft to more than 100ft. This was a 900 Mhz system. If you can easily find the length of wire your controller uses for an antenna, you might want to play around with different antennas (and connecting them through shielded coax wire). It would make your controller a pit more of a pain, since you’d probably need to teather it to a small base where the larger antenna lived. However, if the idea is that the bot moves around while the user sits at a station or something, that wouldn’t be so much of a problem. You also wouldn’t need to mod any electronics or the part on the bot. However, a slightly larger antenna (think a 6 dB one sold for inscreasing WiFi range) would probably help here too.