The RobotShop Rover for Arduino is a small tracked platform designed around the popular Arduino USB microcontroller. In this segment, you will see how to connect the electrical components. Before you begin, you’ll need a soldering iron and solder and a pair of scissors or other cutting tool.
The first thing you will connect is the motor controller. When you receive the kit, you’ll see that the controller’s pin headers are not soldered to the board. Solder the connections to the top of the board, so you can connect it easily to the breadboard and also see the LED’s at the top.
At this point you can stick the solderless breadboards to the frame. The purpose of using breadboards is to allow you to add and remove your choice of additional electronics easily. Note that you can still use Arduino Shields along with the breadboards. If you feel there is not enough room on the three breadboards, you can always create a second level on the Rover dedicated to prototyping.
If you’ve put the Arduino in the center of the frame, you’ll only have enough room for two breadboards towards the front. Two breadboards should provide enough prototyping space for all the electronics that come with the complete kit. You can bend the pre-formed jumper wires to connect between the Arduino microcontroller and the solderless breadboards.
Before you proceed, ensure that nothing is powered and there are no batteries in the battery holders. The pins on the Pololu Dual Serial Motor Controller board are clearly indicated. Note that the controller’s orientation is very important and the processors should be facing you.
Pin one is at the bottom left of the board and is connected to the AA battery holder’s red wire. Pin two is connected to the AA battery holder’s black wire, and also the Arduino’s Ground pin. The third pin is the logic supply, which is used to power the processor on the motor controller. You can connect this to either the 3.3V or 5V output on the Arduino.
Pin number 4, the serial control input, can only be connected to digital pin #2 on the Arduino, which is the Arduino’s serial output pin. The reset pin, pin five, is connected to one of the Arduino’s other digital pins. Pins six and seven are connected to one motor leads, and pins 8 and 9 are connected to the others’s.
Laid out flat, the connections should be done with the pre-formed jumper wires. The wires from the motors and battery packs were run through the holes in the frame, and shortened for aesthetic and do that they would not get caught in the tracks. Don’t shorten the motor’s wires too much if you plan to change the electronics frequently.
Note that we have added an on/off switch to the Arduino’s 5V output pin. If you didn’t add this, you would see that when you downloaded a program to the Arduino, the motor controller would behave erratically until the program finished uploading. Alternatively, you can add the on/off switch between the Arduino’s serial output and the motor controller’s serial input.
If you want to use the Sharp infrared sensor, connecting it is straightforward. You can connect the red lead of the Sharp cable to the AA battery positive voltage, and the black to ground. The yellow signal wire connects to an analog pin on the Arduino. The servo cables are connected much the same way, but instead of connecting the yellow signal wire to an analog pin, you connect it to a digital pin.
Wiring the 9V battery to the Arduino is fairly simple: The cables are slightly too small to stay connected to the Arduino, so we suggest soldering pin connectors to the end of each lead. Connect the red wire to the Vin pin, and connect the black wire to the ground pin. If you have a new Arduino USB microcontroller, the board will automatically determine which power supply to use. For older boards, you will need to change the jumper from USB powered to E X T for external.
To avoid any glitches since we are using two power supplies, the ground wires from the 9V and AA batteries should be connected together. This is what is referred to as “common ground”. This means that the ground pin from the Arduino, the ground from the AA battery holder and 9V battery, as well as the ground of the servos and infrared sensor have to be connected in some way.
The AA battery pack powers the DC motors, the servo motors and the Sharp IR sensor. Notice we’ve extended the AA power supply to a second breadboard using the jumper cables. When you want to include the pan and tilt kit, you can replace these jumper wires with the #22 gauge wire and run it around the servo.