The Ultrasonic Sensor

Plug the 4-pin wire into the top of the HC-SR04 ultrasonic sensor. Insert the sensor into the case with the wires going through the top hole.

Make note of the pins at this point and which color wire they are connected to. These will be needed later.

Secure the lid onto the case. Make sure the fit is secure so that it won't fall off during use.

After the sensor case is assembled and the wires attached, the sensor and housing can be inserted into the slot on the front of the frame. The fit should be good enough that the case will stay in on its own, but a dab of hot glue can be used to make sure it will stay in place.

The wires will be plugged into the following pins:

  • VCC --> 5V
  • TRIG --> 8
  • ECHO --> 7
  • GND --> GND

More details about how to wire the ultrasonic sensor will be found later in the instructions.

The support pillars for the top platform can be installed at this point. The rear support pillar (shaped like an L) will be directly threaded with a screw in the bottom hole.

The two front pieces will have nuts installed that will be used to secure the screws to the pillars.

Place the two M3 hex nuts into the slots on the front pillars. Place a screw through the frame of the RoadRunner and into the bottom of the pillar. Turn the screw until it is securely locked into place in the nut

Before moving on to the next section, the prototyping breadboard can be installed on the back of the RoadRunner. Remove the sticker backing and adhere the board to the frame. This pieces is where most of the wiring will be done later. The breadboard will handle power distribution and signal routing.