Robot Coverage Area

[cambot]

I built and internet controlled robot (a small car the size of a lawn tractor). For the wireless connection on the robot I used a Linksys WRT54G with DD-WRT fireware, v23, in bridge mode. The robot is controlled by a microcontroller with an ethernet connection wired to the onboard router. There is also an Axis IP camera wired to the router. The router is bridged to another Linksys router connected to a cable modem.

Finally, my question. How can I get the most coverage area for the robot? I'm on a 2 acre lot. Should I set up repeaters around the property? Will that even work? WDS? I'm looking for suggestions. I'm better at robotics than networks, but I'll work on it.

The robot can be seen at: http://www.shelato.com/SecurityRobot/

Thanks in advance for any help,

David

[M/Q]

Very interesting project, David.

I would suggest replacing the Linksys devices with a mesh network product like Meraki Networks. The device can act as client adapter or as a mesh AP. As a network it can be deployed and configured via the Dashboard which is an Internet website. The only issue is power and you seem to have that resolved for the car radio. Meraki also makes a solar powered AP system that works quite well and could be used for locations that do not have any infrastructure.

[cambot]

Thank you for the reply M/Q. You've given me something new to look into. I may acutally be able to kill two birds with one stone. There are 3 rental cabins on the property. Maybe I could charge the renters for internet access while expanding my robot coverage area..........

Do you have experience with the Meraki repeaters? I was wordering about the quality and reliability? I noticed that the small repeater only has one ethernet port. I need a port for the Camera and another for the microcontroller. The outdoor unit seems to have two ports though.

[M/Q]

Hello David,

I do not normally recommend anything, check the forum out. I do have experience with the Meraki devices and they do what is advertised. To be honest, I do not know of any better equipment, unless you want to get into business and/or enterprise grade equipment.

As far as I know Meraki equipment only has one Ethernet port on any of their devices. I would then let the car wireless stay as is and use the Meraki equipment for the infrastructure.

[cambot]

I currently have a Linksys WRT54G connected to the cable modem. I have 3 Axis cameras wired to that Linksys. The robot has a Linksys in Client Bridge mode with the microcontroller and and other Camera.

Can I replace the WRT54G on the modem with a switch. Add a Merkai to the switch and then spread more of the Merkais out for the robot to communicate with?

I'm not clear about what to tell the bridged router to talk to. At the moment it has the same SSID as the WRT54G on the modem, and I told it to join that network. The Router on the modem is 192.168.1.1 and the one on the robot is 192.168.1.2.

[M/Q]

With the Meraki mesh network, all you have to do is have one connected to the Internet like you suggested. Still have the Linksys in the car as you need more than one Ethernet port. I think you mentioned that it is setup as a client, if not set it up as such. The other Meraki AP's can be located anywhere you want, just make sure the traffic can find its way back to the one with Internet access , either directly or by daisy-chaining

Check out the Dashboard on their website, that is how you configure the network, just once and it gets sent out to all the individual APs. Simple system and very reliable.

[cambot]

Thanks M/Q. I just purchased 3 of the Meraki units, an outdoor and 2 indoor. I'll write back in a few weeks and let you know how it works. This is great fun. No fears, because there is always an ebay way out ;)

Thanks again,

David

[M/Q]

Good Luck and please let us know how it worked out.

[cambot]

Hi M/Q,

I received my Meraki units today and read through the manual. I have not set them up and have a question before I do. I have a Linksys WRT54GS connected to my cable moden and a WRT54G on the robot which is in client bridge mode. I'm wanting to expand the coverage area for the robot.

The Meraki instrustions say that with existing networks, just plug the meraki unit in and place it where it gets the best signal strength. How does the meraki unit know what network it is repeating or associated with? Is there a setup menu? Or is this done through the dashboad? The instructions that came with the unit are very brief.

[M/Q]

You replace the one connected to the cable modem with one of the Meraki devices and all the others if in range will receive their configuration from that one. The one connected to the cable modem will be configured via the Dashboard over the Internet. The only somewhat annoying thing is that it takes awhile for the change to happen, since it is over the Internet. You get used to it though. The Dashboard has a great help section and that is indeed where you configure the Merakis after you register them.

[cambot]

Thank M/Q

The Meraki units worked great. I can't believe it, my robot car is able to move seemlessly from one repeater to the next. I bought two meraki mini's and an outdoor unit. I'm selling the mini's on ebay and I'm upgrading to all outdoor units. The meraki outdoor unit has nearly the same range of a Linksys WRT54G. or.....maybe that's because my meraki outdoor unit is communicating with the WRT54G on my robot.

At any rate, they work great and I really appreciate your putting me onto them. I like the Dashboard at the Meraki site. Easy setup, once you figure it out :D

Thanks again. I would recommend these for people who want to blanket their home in wifi.

[M/Q]

I am glad that it is working for you. The Meraki system is indeed quite amazing.

If you rather not sell the indoor versions, you could just put them in an enclosure. The internals are identical on the outdoor and indoor versions. I have used simple tupperware containers with the antenna sticking through and siliconed. That may not even be necessary as most plastics do not absorb RF. Just a thought. The outdoor versions do have better temp and humidity ratings though.

[cambot]

Thanks Again M/Q,

They actually list a better range on the outdoor than the mini. I have to admit though, the router on the robot was seeing all three meraki units during most of it's travel outdoors. I had one upstairs in a window and the other two were down stairs in a front and back room.

Do you have ideas about where to find a high gain antenna that will fit these? When I move them to their final destination on the Canadian border, they need to cover a two to three acre lot with several buildings. In the center of the property is a barn and I was planning to put the meraki units on 3 corners of the barn. My dad has a house on a hill overlooking the property (line of site), about 500 feet away from the barn. It would be a plus to give him internet reception. BTW, the internet modem is in the barn. It's a long story......

[M/Q]

I know about that spec, but I am not seeing the difference.

As for antennas if you are going to locate them all on the same building using 120 degree sector antennas will give you the best and largest coverage area. The only thing to remember is that they have to be able to communicate with the Internet facing device. It might be best to use high gain vertical dipoles and try to locate the devices at optimal locations where they will cover the most and still be able to respond to each other.

I use FAB-Corp for all of my antenna needs. They have just about any thing you need including the pig tails to convert between different coaxial cable connections. Try and keep the coaxial cable length to a minimum and use the best grade of cable you can.