B4R will not be used with Raspberry Pi boards. Only with Arduinos. Technically they are very different.What will be the difference between b4r and b4j?
Yes. The example above shows how the Arduino can be controlled from an Android or any other device.Can B4R comunicate with B4A over wifi(of course with wifi hardware) to control B4R by android applications?
Search google for Arduino. Start with Arduino Uno or Mega. You can buy them from ebay or many other online stores.Is there some recommendet links where i can get those boards?
Try eBay or adafruit... Arduino boards can vary from 5€ for a UNO clone to +20€ for an original board.Is there some recommendet links where i can get those boards?
Will b4r be freeware like b4j? What are the plans? (If i may ask )
Do we also need to have a rapsperry pi 2 ?
That robot is a very typical arduino project, like this oneCould i program with b4r such arduino robot?
https://store.arduino.cc/product/AH00009
Will b4r be freeware like b4j? What are the plans? (If i may ask )
lets say that with a heat sensor i want to send the weather data to my mysql db every hourNo, a Raspberry Pi is not necessary, but depends on what you want to achieve.