Begin with just one LM3914 chip as shown in the chalk drawing above. You might want to refer to the LM3914 datasheet.
The HB100 radar is fixed stationary in the environment, and the linear array of LEDs is waved back and forth. It functions as a "target" for the radar, thus returning a Doppler shifted radio signal that is displayed on the dotgraph.
An amplifier of adjustable gain can be used to set the sensitivity of the SWIM depending on how far the dotgraph is from the radar. If you are finding that the gain is insufficient, you can increase the gain of the amplifier, or you can also increase the radar cross section of the target by affixing a piece of metal or other radar reflective material to the dotgraph.
If you want a higher-resolution SWIM, you can cascade the LM3914 chips as shown in the second chalk drawing. Here, rather than using an internally generated reference, we use an external 5 volt reference provided by a 78L05 voltage regulator, which gives us more flexibility.
The picture shown at lower center shows my assembly of three LM3914 chips to drive 30 LEDs. The HB100 radar is shown at the top of the picture, and is what is generating the radio waves that we see.
The picture shown in the lower right is a picture I took of a breadboard setup put together by a student, with 10 LM3914 chips driving 100 LEDs. In my critique of this lesson, I noted that the LEDs should be more carefully arranged in a straight line, because slight flaws in their alignment result in massive disruption of the shape of the waveform. The use of a circuit board with surface mount LEDs resulted in improved performance regarding alignment. Nevertheless, you can quickly and easily implement this "Persistence of Exposure Phenomenal Augmented Reality Effect".
As a teaching tool, this also illustrates the concept of "sitting waves" as compared with standing waves.