Assembly Guide for SparkFun JetBot AI Kit V2.0 a learn.sparkfun.com tutorial

Available online at: http://sfe.io/t1165

Introduction

SparkFun’s version of the JetBot merges the industry leading machine learning capabilities of the NVIDIA Jetson Nano with the vast SparkFun ecosystem of sensors and accessories. Packaged as a ready-to-assemble robotics platform, the SparkFun JetBot AI Kit v2.0 requires no additional components or 3D printing to get started - just assemble the robot, boot up the Jetson Nano, connect to WiFi and start using the JetBot immediately. This combination of advanced technologies in a ready-to-assemble package makes the SparkFun JetBot Kit a standout, delivering one of the strongest robotics platforms on the market. This guide serves as hardware assembly instructions for the JetBot AI Kit v2.0. The SparkFun JetBot comes with a pre-flashed micro SD card image that includes the Nvidia JetBot base image with additional installations of the SparkFun Qwiic Python library, Edimax WiFi driver, AWS RoboMaker ready with AWS IoT Greengrass, and of course the JetBot ROS. Users only need to plug in the SD card and set up the WiFi connection to get started.

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The Jetson Nano Developer Kit offers extensibility through an industry standard GPIO header and associated programming capabilities like the Jetson GPIO Python library. Building off this capability, the SparkFun kit includes the SparkFun Qwiic pHAT for Raspberry Pi, enabling immediate access to the extensive SparkFun Qwiic ecosystem from within the Jetson Nano environment, which makes it easy to integrate more than 30 sensors (no soldering and daisy-chainable).

The SparkFun Qwiic Connect System is an ecosystem of I²C sensors, actuators, shields and cables that make prototyping faster and less prone to error. All Qwiic-enabled boards use a common 1mm pitch, 4-pin JST connector. This reduces the amount of required PCB space, and polarized connections mean you can’t hook it up wrong.

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Materials

Recommended Tools

We did not include any tools in this kit because if you are like us you are looking for an excuse to use the tools you have more than needing new tools to work on your projects. That said, the following tools will be required to assemble your SparkFun JetBot.

• Small phillips & small flat head head screwdriver will be needed for chassis assembly & to tighten the screw terminal connections for each motor. We reccomend the Pocket Screwdriver Set; TOL-12268.
• Pair of scissors will be needed to cut the adhesive Dual Lock Velcro strap to desired size; recommended, but not essential..
• Optional- adjustable wrench or pliers to hold small components (nuts & standoffs) in place while tightening screws; your finger grip is usually enough to hold these in place while tightening screws & helps to ensure nothing is over tightened.

A Note About Directions

When we talk about the "Front," or "Forward" of the JetBot, we are referring to direction the camera is pointed when the JetBot is fully assembled. "Left" and "Right" will be from the perspective of the SparkFun JetBot (i.e. what the JetBot camera sees).

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1. Robotics Chassis Kit Initial Assembly

Begin by with one of the two bare base plates included with the JetBot Chassis Kit. It does not matter which one, they are identical.

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Push two of the included motor mounts through the designated holes in the base plate as shown below. Two more motor mounts will be attached on the outside of the base plate after the motor is installed.

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Your JetBot Chassis Kit includes a pair of hobby motors & wheel assemblies.

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Attach the pair of motors using the long threaded machine screws & nuts included with the JetBot Chassis Kit. The motor will be sandwiched between an internal & external motor mount. Tighten the screws until they are snug.

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Once both motors are attached, flip the base plate over as pictured & thread the motor terminal leads through the baseplate as shown.

Additionally, attach the four longer brass standoffs at each corner of the base plate using the threaded screws included with the JetBot Chassis Kit. Refer to the photograph of the caster ball assembly to make sure you are using the correctly sized brass standoffs.

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Build the ball caster assembly using the two shorter brass standoffs.

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Install the caster ball assembly as shown in the assembled photo below. Additionally, attach the wheels to the hobby motor axles.

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2. Camera Assembly & Installation

Next, locate the camera mount assembly in the JetBot Chassis Kit. The unassembled view of the parts is laid out in the proper orientation for assembly.

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Unpackage the Leopard Imaging camera and assemble the camera mount as shown in the following photograph.

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Please reference the note about the "Front" of the JetBot in the end of the Introduction to ensure that you mount the camera on the correct side of the camera mount. Align the four holes in the camera mounting plate with those on the camera. Place all four nylon flathead screws through the camera & camera mounting plate prior to fully tightening the nylon nuts. This will ensure equal alignment across all four screws. While holding the nuts in place with a finger, tighten the screws in a rotating criss cross pattern; similar to how you tighten lug nuts on a car rim.

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Attach the camera mount & camera to the JetBot Chassis Kit top plate (the unused base plate) using two sets of screws and nuts included in the chassis kit.

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3. Accessory Installation to Main Chassis

Cut the strip of dual lock Velcro into two roughly equal sized strips. Take one side of the dual lock Velcro and attach to the back of the battery pack as shown.

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Place the corresponding pieces of dual lock Velcro on the initial chassis assembly as pictured.

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Press firmly on the battery pack to attach the dual lock Velcro interface between the chassis and battery. Route the motor terminal wires as shown.

Install the included nylon standoffs using the included 4-40 screws (10 packs) on the top mounting plate (the one we just finished attaching our camera and mount to). Pictured below are the standoffs for the Jetson Nano Dev Kit & the SparkFun Qwiic Motor Driver. Be sure to keep the standoffs on the right side somewhat loose. The mounting holes in the top plate are oblong to compensate for manufacturing tolerances & ensure a secure fit to the Jetson Nano Dev Kit.

The last four screws included with the JetBot Chassis Kit (shown on the right of the photo below) will be used to attach the top plate to the brass standoffs on each corner of the base plate.

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Once the chassis is fully assembled, attach the SparkFun Qwiic Motor Driver as shown using the mounting hole on the board to the right of the 4x motor screw terminal. Attach the motor leads as pictured; see below for more details.

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Connect the motor leads according to the table below; remember the "Right"& "Left" designations from the Introduction. They should match the image above. The right motor is on the right side of this photo.

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Install the Micro SD card with the SparkFun JetBot Image (pre flashed) into the Micro SD card slot on the Jetson Nano. It is easier to do this prior to installing the Jetson Nano Dev Kit onto the chassis. This image is from the original JetBot Assembly guide.

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Attach the Jetson Nano Dev Kit using four 4-40 screws to the previously installed Nylon standoffs. Remember we left the right side standoffs loose so align them with the mounting holes on the Jetson Nano Dev Kit & tighten until sung.

Additionally, install the Edimax 2in1 USB WiFi & Bluetooth adaptor into any of the USB ports on the Jetson Nano Dev Kit.

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Attach the 100mm Qwiic cable to the underside of the SparkFun Qwiic Micro OLED as shown below.

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Attach the SparkFun Qwiic Micro OLED to the JetBot Chassis using another Nylon Standoff & 4-40 screw. Attach the 100mm Qwiic cable to the SparkFun Qwiic Motor Driver. Secure the Qwiic Micro OLED by tightening the screw until sung.

Connect the qwiic pHAT on the Jetson Nano Dev Kit's 2x20 GPIO headers taking care to align it as the photo below shows.

Attach the Leopard Imaging camera ribbon cable to the Jetson Nano Dev Kit's front-most camera connector.

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Connect the SparkFun Qwiic Micro OLED display to the Qwiic pHAT using the 200mm Qwiic cable.

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Finally attach the Qwiic Motor Driver's motor power screw terminals to the 2 pin screw terminal for 5V and Ground on the Qwiic pHAT using the included 6 inch M/M jumper wires. We recommend using one black wire (ground) & one red wire (power), but you can use any included color your head desires.

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Use the included 6 inch USB Micro-B Cable to connect the Jetson Nano Dev Kit to the battery pack.

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Allow the JetBot a few minutes to power up. When the JetBot is ready the Micro OLED will display the SparkFun flame logo, followed by the available disk image space & IP address once connected to a WiFi network.

4. Software Setup Guide from NVIDIA

Your SparkFun JetBot comes with a Pre-Flashed micro SD card. Users only need to plug in the SD card and set up the WiFi connection to get started.

• The default password on everything (i.e. login/user, jupyter notebook, and superuser) is "jetbot".
• We recommend that users change their passwords after initial setup. These are typically covered on the first boot of your Jetson Nano as detailed in the NVIDIA Getting Started with Jetson Nano walkthrough

Software Setup

The only step needed to get your JetBot kit up and running is to log into the JetBot and setup your WiFi connection. Once that is done, you are now ready to connect to the JetBot wirelessly. If you need instructions for doing so, you can use the link below.

Instructions

1. Skip step 1 of Nvidia's instructions: It references how to flash your SD card, so feel free to skip to Step 2 - Boot Jetson Nano.

2. Skip step 5 of Nvidia's instructions: This step should already be setup on the pre-flashed SD card.
   • If in the future, you need to update your notebooks, you can follow Step 5 - Install latest software (optional) to download the repository (don't download it into the home directory and skip the last command line instruction of the forth step).

Get and install the latest JetBot repository from GitHub by entering the following commands

git clone https://github.com/NVIDIA-AI-IOT/jetbot
cd jetbot
sudo python3 setup.py install

Troubleshooting

In the event that you accidentally missed the instructions above, here are instructions to get back on track.

Re-Flashing the SD card

If you need to re-flash your SD card, follow the instructions from Step 1 Nvidia's guide. However, download and use our image instead (click link below).

Alternatively, there are other options for flashing images onto an SD card. If you have a preferred method, feel free to use the option you are most comfortable with.

Re-Applying the Software Modifications

If you have accidentally overwritten the software modifications for the hardware included in your kit, you will need to repeat Step 5 from Nvidia's guide from the desktop interface (if you are comfortable performing the following steps from the command line, feel free to do so).

Skip steps 1 and 2: Plug in a keyboard, mouse, and monitor. Then log in to the desktop interface (if you haven't changed your password, the default password is: jetbot).

Follow step 3: Launch the terminal. There is an icon on sidebar on the left hand side. Otherwise, you can use the keyboard short cut (Ctrl + Alt + T).

Follow step 4: However, before you execute sudo python3 setup.py install you will want to copy in our file modifications to the jetbot directory you are in.

1. Begin by downloading our files (click link below).

2. Next, extract the file.

3. Next, replace the files in the jetbot folder. The file paths must be the same, so make sure to overwrite files exactly.

Click on the icon that looks like a filing cabinet on the left hand side of the GUI. This is your Home directory. From here, you will need to proceed into the jetbot folder. There you will find a jetbot folder with similar files to the ones you just extracted. Delete the folder and copy in our files (you can also just overwrite the files as well).

4. Now, you can execute sudo python3 setup.py install in the terminal.

Follow step 5: Finish up by following step 5. Now you are back on track to getting your JetBot running again!

5. Examples

Resources and Going Further

Now that you've successfully got your JetBot AI up and running, it's time to incorporate it into your own project!

For more information, check out the resources below:

• Getting Started With Jetson Nano Developer Kit
• Assembly Guide for SparkFun JetBot AI Kit (previous version)
• SparkFun Qwiic Motor Driver Hookup Guide
• SparkFun Qwiic Micro OLED Hookup Guide
• SparkFun Qwiic pHAT Hookup Guide
• JetBot ROS GitHub Repository
• Getting Started with AWS IoT Greengrass
• NVIDIA Jetson Forums
• NVIDIA JetBot GitHub Issues
• NVIDIA JetBot GitHub
• NVIDIA JetBot GitHub Wiki
• NVIDIA JetBot software setup

Need some inspiration for your next project? Check out some of these related tutorials:

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