I’ve been assembling a Mintduino, which is a breadboard version of an Arduino. The above photo shows me about midway through the process.
The Mintduino case is a mint tin, hence the name. The case holds the electronic components shown plus the breadboard and the battery clip (battery not included). I soldered short solid leads onto the battery clip leads, since the braids of the clip leads didn’t go into the breadboard holes very well.
The FTDI “Friend” is needed to program the Mintduino from your computer and does not come with the Mintduino package. The A to B USB cable doesn’t come with the Mintduino or the FTDI “Friend” but fortunately I had one laying around. Possibly you do too, they’re quite common.
Once I get the Mintduino up and running, it should be fairly straightforward to pry off the ATMEGA328 chip and see about using it by itself without all the support circuitry of the Arduino prototyping platform. That will be a big step toward making a low-cost robot.