I was thinking an accelerometer, optical shaft encoder, gyroscope, pretty much all the sensors. And I would like relatively high speed, but not in which I would have to pay an extremely high amount. Also, a range of 100-200 ft.
The cheapest item you show runs at 4800 bits per second, or 480 bytes per second (in serial connections there is a start bit, 8 data bits and a stop bit, so 10 bits ~ 1 data byte). That would give you a 48 byte data packet 10 times a second. With two bytes per device, you could send info for 20 devices (I’d send a header / trailer message so I knew where the packet starts and stops)
So the cheapest item would work. You would need to make cables up to attach to the Vex and the other device (laptop?) – one thing to note, you can only use one transmitter, so it’s only one way communications
The Bluetooth/serial would also work, it would be easier to attach to the laptop, still needs a Vex cable. It is expensive, but it would give you two way communications
The Xbee boards work. I’ve used them and after an initial startup problem they have worked fine.
Vexnet: Would come with the software support and would be plug and play. I don’t know the pricing, but I’d guess that it will be the most expensive of the solutions you show.
Three of the solutions can be in your fingers in a day with the help of FedEx. The Vexnet is coming “soon”, how much do you want to wait?
Sorry if this is old technology, but I was just looking around the internet when I found a great idea. I found a service called LogMeIn.com. With this you can access your computer on any computer in the world. You can do pretty much everything that your computer can do. For example, say I am on a trip in California and I live in Pennsylvania. I can access my computer in PA from the computer I am on in California. How does this relate to VEX? As long as a robot is connected to the computer in PA, such as a robotic arm or any other stationary robot, I could control it from California. This works even if I dont have EascyC or a programming software installed on my PC in California.
Of course there are a few problems. If you wanted to have an actual robot that drives around your house, you would need a way to communicate wirelessly. Once again back to the idea of wireless communication between a pc and robot? Also, you would need to leave a robot on in order to control it. Does any one have any ideas on how to turn a robot on remotely? Or you could just make a dc adapter that plugs into the wall. This way when it comes time for the robot to be controlled, it is already on.
As you can see, I am pretty excited with the find of LogMeIn. I think there are many things that could come out of this. My plan is to make a stationary robot that can pan and tilt with a webcam on it. Then I could watch over my house from any computer in the world.
A slight bit of a problem there. The battery on the vex robot is good for probably half a day under minimal load and less if you drive it around. Unless you find a charger or something that’ll connnect to your bot, by the time you reach california your bot will have died =/