To control RoboBoblet a communication link is needed. For this I decided to use a HC06 Bluetooth interface as they are cheap and easy to implement having only four connections (0V, 5V, Tx, Rx). I like my user interfaces to be text based with all the intelligence on the controller and then using a dumb display. For the dumb display I have used an App called BlueTerm (there is also BlueTerm 2) running on an Android phone. It can get a bit difficult to find the same one as I have used as there are many BlueTerm type apps doing all sorts of different things. The first YouTube below shows the HC06 and smart phone combination being checked for correct operation before installing onto RoboBobLet. Sorry about it being out of focus, I might need lessons in how to make videos.
After making sure that the Bluetooth link will work the HC06 can simply be connected to RoboBobLet. The HC06 has an on-board voltage regulator so is safe (so far) to use with the roughly 6V battery pack used with RoboBobLet, and is just connected directly to the Tx and Rx pins of the Nano (Rx to Tx). When doing the connections this way you have to remember that you cannot then plug in the USB cable to programme the Nano as the two serial sources interfere with each other. The HC06 has to be removed during programming.
The Nano C programme now has a user interface (text based via the HC06) that allows the user to choose one of four movements; forwards, backwards, rotate left and rotate right, that can be easily selected using the smart phone. Each movement only runs for a second to avoid any crashing into objects, walls and so on. The second YouTube video below shows RoboBobLet working.
The next step is to add sensors to RoboBobLet so that it can start to operate autonomously.