Unbox and Set Up your Viam Rover
The Viam Rover arrives preassembled with two encoded motors with suspension, a webcam with a microphone unit, and a 3D accelerometer module.
Note
You must purchase the following hardware separately:
- A Raspberry Pi 4
- Four 18650 batteries (with charger)
- A MicroSD card and an adapter/reader
This guide covers what’s inside the kit, describes each component, provides instructions for wiring your rover, and includes links for additional hardware.
What’s inside the kit
One assembled Viam Rover.
Four M2.5 screws for mounting your Raspberry Pi.
Two spare stiffer suspension springs. You can swap them out with the springs that come with the rover if you need stiffer suspension for higher payload applications.
Three different Allen wrenches (1.5 mm, 2 mm, and 2.5 mm) to unscrew the top and mount the Raspberry Pi.
- Ten female-to-female jumper wires. All of the wires’ colors correspond to the included wiring diagram. Six are for the motor controller and four are for the accelerometer.
All together, your kit looks like this:
Rover components
Dual drive motors with suspension and integrated motor encoders
The motors come with integrated encoders. For information on encoders, see Encoder Component. For more information on encoded DC motors, see Encoded Motors.
The kit also includes stiffer suspension springs that you can substitute for the ones on the rover. Generally, a stiff suspension helps with precise steering control. In contrast, a soft suspension allows the wheels to move up and down to absorb small bumps on the rover’s path.
Motor driver
The kit comes with an L298N driver dual H-Bridge DC motor driver. L298 is a high voltage and high current motor drive chip, and H-Bridge is typically used to control the rotating direction and speed of DC motors.
720p webcam, with integrated microphone
The webcam that comes with the kit is a standard USB camera device and the rover has a custom camera mount for it. For more information, see Camera Component.
3D accelerometer
The ADXL345 sensor manufactured by Analog Devices is a digital 3-axis accelerometer that can read acceleration up to ±16g for high-resolution (13-bit) measurements. You can access it with a SPI (3-wire or 4-wire) or I2C digital interface.
In Viam, you can configure it as a movement sensor component.
Buck converter
A buck converter is a DC-to-DC power converter and you use it to step down voltage from its input to its output. The 5A mini560 step-down module has high conversion efficiency and low heat generation.
Toggle switch
The toggle switch comes wired to the rover and you use it to turn the power on and off.
Battery pack
The rover comes with a battery holder. You must purchase four 18650 batteries (and a charger) separately. The battery holder also has a female jack for an external DC power supply.
Four 18650 batteries with a charger
An 18650 battery is a lithium-ion rechargeable battery. We recommend the button-top type, though either button or flat top can work. We have used batteries approximately 67.5mm in length, but the battery housing includes a spring to accommodate most batteries of that approximate length. Any brand is suitable as long as you comply with the battery safety requirements.
Check the safety section for more information.
Safety
Read all instructions fully before using this product.
This product is not a toy and is not suitable for children under 12.
Switch the rover off when not in use.
Warning
Lithium-ion batteries may pose a flammable hazard. This product requires four 18650 lithium-ion batteries. Refer to the battery manufacturer’s operating instructions to ensure safe operation of the Viam Rover. Dispose of lithium-ion batteries per manufacturer instructions.
Caution
Damage may occur to the Raspberry Pi and/or Viam Rover if wired incorrectly. Refer to the manufacturer’s instructions for correct wiring.
Disclaimer: This product is preliminary and experimental in nature, and is provided “AS IS” without any representation or warranty of any kind. Viam does not make any promise or warranty that the product will meet your requirements or be error free. Some states do not allow the exclusion or disclaimer of implied warranties, so the above exclusions may not apply to you.
Setup
This is the recommended order to assemble your rover:
- Install Raspberry Pi OS on the microSD card.
- Unscrew the top of the rover and screw the Pi to the base.
- Conenct the components.
- Screw the top of the rover back on and turn the rover on.
- Install
viam-serverand connect to the Viam app.
Install Raspberry Pi OS
Install a 64-bit Raspberry Pi OS with the Raspberry Pi imager and put it in your Pi’s microSD card slot. For more detailed instructions, check out our Raspberry Pi installation guide.
Attach the Raspberry Pi to the Rover
Once you have installed Raspberry Pi OS and viam-server, put your SD card in the slot on your Pi.
To be able to attach the Raspberry Pi, unscrew the top of the rover with the biggest Allen key.
Then use the smallest Allen key and the provided M2.5 screws to attach the Raspberry Pi to your rover in the designated spots.
The following image shows the four mounting holes for the Pi, circled in red:
Tip
The rover’s design allows you to reach the SD card slot at all times, so you can remove or reinsert the SD card without removing the top of the rover.
Connect the wires
Tip
To make it easier for you to see which pin is which, you can print out this piece of paper at 100% scaling level which has labels for the pins and carefully push it onto the pins or fold or cut it so you can hold it up to the Raspberry Pi pins. Only attach the paper when the Pi is unplugged. To make attaching the paper easier, use a credit card or a small screwdriver.
Wire your Pi to the buck converter, the acceleration tilt module, the DC motor driver:
The following pinout corresponds to the diagram:
| Component | Component Pin | Raspberry Pi Pin | Wire Color |
|---|---|---|---|
| Buck Converter | GND | 39 | black |
| Buck Converter | 5V | 4 | red |
| Acceleration Tilt Module | GND | 34 | black |
| Acceleration Tilt Module | 3.3V power | 17 | red |
| Acceleration Tilt Module | SDA | 3 | maroon |
| Acceleration Tilt Module | SCL | 5 | pink |
| DC Motor Driver | En B | 22 | gray |
| DC Motor Driver | In 4 | 18 | yellow |
| DC Motor Driver | In 3 | 16 | white |
| DC Motor Driver | In 2 | 13 | green |
| DC Motor Driver | In 1 | 11 | blue |
| DC Motor Driver | En A | 15 | purple |
| DC Motor Driver | GND | 6 | black |
| DC Motor Driver | Encoder Left | 35 | yellow |
| DC Motor Driver | 3.3V power | 1 | red |
| DC Motor Driver | Encoder Right | 37 | white |
Tip
En A and En B pins have little plastic jumpers that you need to remove before wiring.
The motor driver on the Viam Rover has 8 pins and 6 wires. You must wire it with the outside row pins:
Then connect the camera’s USB cable to the Pi.
Turn the rover on
Once you have wired up all the components, reattach the top of the rover and fasten the screws. Insert the batteries and turn the rover on. If the Pi has power, the lights on the Raspberry Pi will light up.
Connect to the Viam app
While the Pi boots, go to app.viam.com and add a robot.
On the robot’s SETUP tab, select Linux and Aarch64.
SSH into the Pi and follow the instructions on the robot’s SETUP tab to download viam-server and configure your robot.
To configure your rover so you can start driving it, add the Viam Fragment to your Robot.
Next Steps
Check out our other tutorials that use the Viam Rover.
Rover Build
If you want to learn more about the rover, you can find the CAD files and bill-of-materials (BOM) on GitHub.
Extensibility
Due to the aluminum chassis and its expandable mounting features, you can extend the Viam Rover. With it, you can customize your rover by mounting additional sensors, lidar, robot arms, or other components. The following are just a few ideas, but you can expand or modify the rover kit with any components you want:
- For GPS navigation, we support NMEA (using serial and I2C) and RTK. Make and model don’t make a difference as long as you use these protocols. See Movement Sensor Component for more information.
- For LiDAR laser range scanning, we recommend Velodyne, or RPLIDAR (including A1, which is a sub-$100 LIDAR).
- For robot arms, we tried the Yahboom DOFBOT robotics arm with success.