FPV Car with video and control via 3G data link
In the last post the connection between the Android smartphone and an RC Car was established. Now it’s also possible to have a connection from the smartphone to the Internet for both, video streaming and remote controlling (RC). Both is needed for a first person view controlling of a vehicle.
But why controlling a FPV car via Internet? Because theoretically there is no limit about the range except the battery capacity. Normal FPV gear and RC components have without the need of a special radio license in Germany a range about half or one kilometer with clear line of sight between sender and receiver. On ground it’s even less, maybe 100 or 200 meter at best. With a 3G data link it depends on the telecommunication net which is big on most places. That’s the reason for doing a little bit “research” on this topic.
The video can be produced through the on board cam of the smartphone. The cam video can be streamed to the net. I use Skype ™ for this purpose, because it’s fast and easy available for my Galaxy S2 and support video telephony.
The tricky part was the car controlling. I decided to establish the connection from the smartphone to my laptop. This worked well even through the home router. Next part was the protocol. TCP is not the perfect option, because it can be very slow with all the checks in it. UDP is much better, because it doesn’t matter if some of the controlling information don’t reach the car. It’s much more important that – new – controlling information coming fast to the car.
For this the smartphone act as the client. On the laptop site there is a small server software which communicate with the smartphone. This software wait for the initial UDP connection of the smartphone and send after that control information via UDP to the smartphone. The smartphone transmit these information via Bluetooth to the Arduino.
A first test show that this all works together but with a lack of accuracy and some delay.
I think the software part of this approach can be improved for faster and better reactions and also more reliability. This approach also use 3G data link and IPv4. You can imagine how this will be improved if IPv6 and 4G data link is available.