Will such an adapter work with the stock FRC radio?
We would like to connect two Axis cameras, a Raspberry Pi and the roboRIO into the radio but since the new radio only has 2 ports, we are having difficulties doing so.
Thanks!
The roboRIO must connect by itself to one of the ports, so that leaves a single port to support three devices plus a tethering port.
I’d suggest using a small network switch.
We are running out of space so for us a network switch would not be ideal, do you happen to know if a simple 1 to 2 Ethernet splitter would work?
I haven’t tried it myself, but I’m pretty sure it’s not going to work.
Only one device can be on at one time.
If they all try to talk it’ll only be so much noise.
You’d have to have a 1-to-2 connected directly to two other 1-to-2, for a final 4 to 1.
If you are talking about these:
From the description:
NOTE: This Ethernet splitter allows two computers to share one Ethernet line ONE AT A TIME, but it doesn’t support both computer to connect onto the internet simultaneously.
So the answer to your question is no, it will not work. You need to use a small switch or hub. I’ve posted one that will work in prior messages. It’s pretty small, I’m going to bet you do have room for it.
In the real world I spent a few days sorting out someone that bought these to hook their laptop into the same connection as their company supplied desktop. Lots of random “having problems with my internet” that I couldn’t figure out. Every time I came over they had unplugged the laptop and put it away. I only figured out when I walked by on a random visit and the laptop and the bogus connections were plugged in.
We are running into a similar problem, and will probably end up using something like this. It is a 4 port switch not much bigger than the router, and available for less than $10. It can be powered off the VRM. A splitter will not work, as you need one on each end of the cable. They take advantage of the fact that 10/100 ethernet cables have 8 wires, even though they only need 4. They basically send two ethernet connections through one cable, as I understand it. So you still need two output ports at the end.
Since you are not a rookie team, you should have some d-links lying around. Turn off the wifi, and they will work fine as a hub.
We’re not yet using these in production, so I can’t claim to know that they worked perfectly, but this was the smallest 5v switch I could find on Newegg:
http://www.newegg.com/Product/Product.aspx?Item=N82E16833156250
and size wize, it’s not too bad.
Cheers,
Jeremy
Is it legal to leave an extra 4 port hub / switch on the robot during competition? Its just a “custom circuit” right?
Brian
We use a basic 5 port netgear prosafe switch on our bot
We used a network switch for our Axis Camera and vision tracking in San Diego because we only realized there there needed to be one open Ethernet port to tether. Team 2485 was using it and they helped us set it up along with the Control System FTAs at the competition. We only found success after changing all the IPs (RoboRIO, Driver Station, and Camera) to static IPs. The suggested switches are similar to ours. We eventually took it off because of robot problems in a match, possibly because it wasn’t stable. I would just use it to test vision tracking in the pit/practice field and not use the switch in a match.
We use a D-Link GO-SW-5G gigabit switch on board our robot. It is the tiniest switch you have ever seen. We power it off the 5V connection on the VRM.
It is legal as long as the hub:
- Does not broadcast a wifi signal
- The hub does not have a DHCP server (or it is turned off).
We ran into this issue this weekend and one of our mentors ran out and grabbed this http://www.linksys.com/us/p/P-SE3005/?gclid=CjwKEAiAmY-3BRDh7pjvg46p1iYSJADQ78gNIRh3g51b0ndPFkyo2IF5hJA8o70S2pBZ8dKpBs2AkxoCVBTw_wcB . Worked quite well (except for when the same mentor got a little bit trigger happy and sliced the barrel off in addition to the wall charger! 
another team had a spare barrel plug though)