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Wireless router for a hybrid racecar: what range can I get?

J

jeffy.dee-lux

macrumors 6502a
Original poster
Nov 19, 2003
721
0
montreal
Hi there, I'm working on a series hybrid gas-electric racecar as part of the Formula Hybrid international competition. We've got a piece of National Instruments hardware that we use for control and data acquisition on the car. I'd like to put a wireless router on the car, the NI hardware has an ethernet port so it can plug right into the router, and when the car's in range, I should be able to view any interesting info from the car from my laptop in the pits.

I'm just wondering what I should be able to expect in terms of range when we take this thing outside? Are there any routers out there that have a particularly long range? I know its not exactly a mac topic, but MR is a pretty knowledgeable crew, so I thought I'd ask here. I know an 802.11n router is the way to go. Also I prefer anything that happens to run off of 12V since we've already got a 12V circuit on the car, I know my old linksys AC adapter spat out 12V. Thanks for your input!

PS it is indeed a mac that's connecting to this hardware, my trusty MBP, albeit always through Windows. The mac version of LabView is not exactly complete unfortunately!
 
Well, some Linksys routers have GPL firmware, so there are third party options. Some of those third parties allow you to bump up the transmission power, but don't let the freakin' FCC find out.
You could also make your own antenna for it as well, which will help with range.
 
Id suggest getting a router with external antenna hookups so that you can upgrade to a higher level omni antenna. A lot of the internal ones are crap and since you are talking about a car directional or semi-directional ant. which will ultimately get you the best range aren't going to work.
 
Since you are talking about a race car I would assume it would be zipping by pretty fast. Thus you may not even have enough time to establish a connection before it is out of range again. Since it takes it a while to automatically recognize a router in range and connect.

I would opt for 3G instead so that you can use the cellphone networks. Though you would need to put a laptop in there to transmit the data. Unless the company that makes your device has software for it to connect to Windows Mobile, Android, Palm etc... Though you could use a netbook with a 3G adapter and ethernet to keep the weight down.

You can even get 4.8" and 7" touchscreen netbooks. Some 7" models come with window mounts which you can probably get for the 4.8" models. So they driver can have data displayed they may find useful while driving. You would need a router for inside the car as these only have one USB port which would be used for the 3G connection.

Either setup would entail using remote desktop. But you could use a Mac in the pit to view the data either way.:D
 
How big is the circuit?

You might get away with a well mounted omni on the car - and a directional antenna at the pits, tracking it. Alternatively, schedule it to do a data dump once a lap.
 
How much money do you have to spend? You're going to jump through some technical hoops if you stick with consumer hardware. For example, if you go with a standard consumer router on which you can run open firmware (OpenWRT/DDwrt, etc) with an external antenna, it might be doable.

OTOH, if you have access to the funds or can get a sponsored donation, Cisco has real hardware that will be more than enough for your needs. That's real equipment, real money and you'll need some familiarity with Cisco IOS but overall, it's a better solution.
 
thanks for all the great replies, there are some really good ideas here. I especially like velocityg4's suggestion with the touchscreen netbook, as we were already looking at getting a touch screen in there for the dashboard. In fact we already had a palm pilot hooked up on the dash last year, but it didn't work out perfectly. The current plan for the dash was to actually use a touch screen PC with an RS232 port to connect to the NI controller, and then use the ethernet port on the controller to connect a router. Using 3G is a pretty interesting idea though, I'll look into that.

All that said, I should have mentioned that this car is much smaller than your standard race car, imagine something about half way between F1 and a tiny go-kart, that can give you the right picture. When we're testing, we're generally driving around in a medium sized parking lot, so I don't need a massive range... If I can get about 3-400 meters from a consumer router, I'll be really happy. If it looks like we have to step up to something more serious in the many hundreds of dollars range, I think we'll have to just give it a pass unfortunately.

Can regular wi-fi deal with a moving router though? It's not crazy fast, at most, we might get up to say 50mph once in a blue moon, but we spend most of our time in a turn.

here's a video from two weeks ago:
http://vimeo.com/6834749

djellison, you mentioned using an omni antenna on the car, and then a directional one in the pits.... How would I do this? Get a second router and bridge the two networks? Or can you get a USB wifi antenna that just plugs into your laptop?
 
Barely anything. Go for proper radio.

I'm guessing your NI DAQ has a USB port as well. Why not look into a wireless USB extender? They can go a couple of hundred meters sometimes.

When considering live telemetry you have to think about what benefit it will really give you over just logging and looking back at the data afterwards. Especially when you can't send information back to the car to change settings.
 
SpookTheHamster said:
Barely anything. Go for proper radio.

I'm guessing your NI DAQ has a USB port as well. Why not look into a wireless USB extender? They can go a couple of hundred meters sometimes.

When considering live telemetry you have to think about what benefit it will really give you over just logging and looking back at the data afterwards. Especially when you can't send information back to the car to change settings.
Click to expand...

So you're saying I'll hardly be able to get any range out of a regular wireless router? When you say go for proper radio, what kind of options do I have there? The wireless router is attractive because it would be a very simple solution in terms of how the hardware works (its a compactRIO).

I've looked around at USB extenders as you suggested, but they all seem to be in the 30-100m range, which isn't quite enough. My hardware also only supports basic write to file functionality on the USB port, whereas a network connection would give me full integration with the controller, including changing settings on the car while it's running.

Remote telemetry will really help during a race in terms of planning our strategy throughout the race and with pit stops. We have an on-board generator, and its up to us to use as little fuel as possible. The driver's too busy watching the rode to start doing calculations on how much he needs to run the engine.
 
By proper radio I mean motorsport-spec equipment, but you're not really going to have any options for plugging that into an NI DAQ.

If you're going to try WiFi, some of the Pre-N MIMO routers have distances of up to 1,500ft (Belkin is apparently the long-distance champ). Like others said, make or buy your own antennas for both the car and base station. Get a clear line of sight to everywhere the car goes (this may necessitate putting the base station on top of the pits).
 
The only problem with the 3G I did not think about earlier would be latency as it would go through the cell network.

If you want the maximum range possible I would get a Wireless-N router which uses three external antennae then use these heavy duty 10dbi antennae. Perhaps you could mount them near the rear window. Then on your laptop use one of these USB 2.0 Wireless-N adapters with removable antennae and replace with more of the 10dbi one mentioned. That ought to give you some good range.:cool:

Cisco also makes some really high end 9dbi antennae which are probably higher quality than the Hawking and much more expensive.

I should note these antennae are huge at about 35" long. But they are about the best you will get for omni directional units. If we were talking straightaways. Then you could get a dish network satellite dish wire it to a wifi card on your laptop and get miles of range out of it.:D
 
You need a decent wireless N router and something along the line of a Parabolic or can-type antenna. Best bet is to DIY it. You can get way better results that way, and not pay half as much for some of the crap in the stores...
 
Great, thanks for all the advice. Just to clarify, my plan was to actually put the base station on the car itself, running off the 12V circuit (so far I know some belkin and linksys routers run on 12V). That way I can simply plug the hardware directly to the router via ethernet. This thing typically communicates to a PC either directly with an ethernet crossover cable, or by just plugging it into a network, so plugging this into a wifi router should work right out of the box as far as I know.

Another option to boost range would be to just get a second router that would remain stationary somewhere central to the track and use it to bridge the network. Then of course I've gotta worry about getting power to that second router, but if it can run on 12V, i've got plenty of deep cycle batteries kicking around, so i could just run it directly off one of those.

I'll definitely look into building my own antenna. So I gather some routers come with a detachable antenna that you could replace?? This Belkin router for example looks like it has fixed antennas right? Could I just crack those open and solder on my own antenna?
 
You might see good results with one of the 200mw routers on a 12V supply, and replacing the antenna with a high gain one. That website now has an example of a D-Link router with yagi that getl really long range.

There are router and antenna photos on http://www.ab9il.net/wlan-projects/wifi7.html and the yagi looks small enough to fit okay.
 
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