Assembly Guide for SparkFun JetBot AI Kit a learn.sparkfun.com tutorial
Available online at: http://sfe.io/t933
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 Kit requires no additional components or 3D printing to get started - just assemble the robot, boot up the Jetson Nano 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 two kits that SparkFun sells; Jetbot including Jetson Nano & the Jetbot add-on kit without the NVIDIA Jetson Nano.
NOTE: We recommend that you read all of the directions first, before building your Jetbot. However, we empathize if you are just here for the pictures & a general feel for the SparkFun Jetbot. We are also those people who on occasion void warranties & recycle unopened instructions manuals.
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).
Materials
The SparkFun Jetbot Kit contains the following pieces; roughly top to bottom, left to right.
| Part | Qty |
|---|---|
| Circular Robotics Chassis Kit (Two-Layer) | 1 |
| Lithium Ion Battery Pack - 10Ah (3A/1A USB Ports) | 1 |
| Ball Caster Metal - 3/8" | 1 |
| Edimax 2-in-1 WiFi and Bluetooth 4.0 Adapter | 1 |
| Header - male - PTH - 40 pin – straight | 1 |
| 2 in - 22 gauge solid core hookup wire (red) | 1 |
| Shadow Chassis Motor (pair) | 1 |
| Jetson Dev Kit (Optional) | 1 |
| SparkFun JetBot Acrylic Mounting Plate | 1 |
| SparkFun Jetbot image (Pre Flashed) | 1 |
| Leopard Imaging 145 FOV Camera | 1 |
| Screw Terminals 2.54mm Pitch (2-Pin) | 2 |
| SparkFun Micro OLED Breakout (Qwiic) | 1 |
| SparkFun microB USB Breakout | 1 |
| SparkFun Serial Controlled Motor Driver | 1 |
| Breadboard Mini Self-Adhesive Red | 1 |
| SparkFun Qwiic HAT for Raspberry Pi | 1 |
| SparkFun JetBot Acrylic sidewall for camera mount | 2 |
| SparkFun JetBot Acrylic Camera mount & 4x nylon mounting hardware | 1 |
| Qwiic Cable - 100mm | 1 |
| Qwiic Cable - Female Jumper (4-pin) | 1 |
| Wheels & Tires - included as part of circular robotics chassis | 2 |
| USB Micro-B Cable - 6" | 2 |
| Dual Lock Velcro | 1 |
| Part | Qty |
|---|---|
| Hex Standoff #4-40 Alum 2-3/8" | 3 |
| Standoff - Nylon (4-40; 3/8in.) | 10 |
| 1/4" Phillips Screw with 4-40 Thread | 20 |
| Machine Screw Nut - 4-40 | 10 |
| Circular Robotics Chassis Kit (Two-Layer) Hardware | 1 |
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.
- 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 Velcro strap to size.
- Soldering kit - example TOL-14681
Optional- adjustable wrench or pliers to hold small components (nuts & standoffs) in place while tightening screws; otherwise your finger grip is usually enough to hold these in place while tightening screws.
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.
1. Circular Robotics Chassis Kit (Two-Layer) assembly
Start by attaching the chassis motor mount tabs to each of the "Shadow Chassis Motors (pair)" using the long threaded machine screws & nuts included with the Circular Robotics Chassis Kit.
The motor mounts fit into two mirrored inlets in each base plate as shown. Install the motors opposite of one another. Depending on how you install the motor mounts it will dictate how the motor can be installed on the base plate. Note: Do not worry about the motor orientation as you will determine proper motor operation in how you connect the motor leads to the SparkFun Serial Controlled Motor Driver.
Place the other circular robot chassis plate on top of and align the two "+" and the motor mount tab recesses. Hold the sandwiched chassis together with one hand and install the remaining phillips head screws included with the Circular Robotics Chassis Kit.
There is additionally a very small caster wheel assembly included with the Circular Robotics Chassis Kit, but we have included a larger metal caster ball to increase the stability of the SparkFun Jetbot. We will cover the installation of this caster ball later in the tutorial.
If you prefer to follow along with a video, check out this feature from the chassis product page
Utilize three of the included "1/4" Phillips Screw with 4-40 Thread" through the top chassis plate & install the "Hex Standoff #4-40 Alum 2-3/8"" until they are hand tight.
Un-package the 3/8 in Metal Caster Ball and thread the mounting screws through all pieces as shown. Note this stack height will balance the Jetbot as stable as possible.
2. Camera assembly & installation
Unpackage the Leopard Imaging camera & align the four holes in the acrylic mounting plate with those on the camera. Note ensure that the ribbon cable is extending over the acrylic plate on the edge that does not have mounting holes near the edge; as shown below. Place all four nylon flathead screws through the camera & acrylic mounting plate prior to tightening the nylon nuts. This will ensure equal alignment across all four screws. Tighten the screws while holding the nuts with finger pressure in a rotating criss cross pattern; similar to how you tighten lug nuts on a car rim.
Align the acrylic sidewalls as shown below ensuring that the widest section is oriented to the top of the camera mount where the ribbon cable extends.
Press with even pressure on each piece until they fit together. Note: these pieces are designed to have an interference fit and will have a nice, satisfying "click" when they fit together.
The fully assembled camera mount.
The camera mount should now be installed to the SparkFun Jetbot acrylic mounting plate using the overlapping groove joints. Ensure that the cut out on the acrylic mounting plate is facing towards the front/right of the Jetbot as shown. This will ensure that there is plenty of room for the camera ribbon cable to pass around the assembly and up to the Jetson nano camera connector.
Utilize three more of the "1/4 in 4-40 Phillips head screws" to install the SparkFun Jetbot acrylic mounting plate to the aluminum standoffs extending from the Two-layer circular robotics chassis as shown below.
3. Motor Driver assembly & configuration
To get started, make sure that you are familiar with the SparkFun Serial Controlled Motor Driver Hookup Guide; linked.
- The 2-pin screw terminals are soldered to the "Motor Connections."
- Break off 4 Male PTH straight headers and solder into the "Power (VIN) connection" points.
- Break off 5 Male PTH straight headers and solder into the "Expansion port" points. This will provide additional board stability when installed into the mini breadboard.
- Break off 5 Male PTH straight headers and solder into the "User port" points for connection into the included Female Jumper Qwiic cables.
We recommend familiarizing yourself with the Hardware Overview of the SparkFun Serial Controlled Motor Driver Here.
You will need to solder the two "I2C pull-up enable jumpers" as the SparkFun PHat utilized the I2C protocol. The default I2C address that is used by the pre-flashed SparkFun Jetbot image is 0x5D which is equavalent to soldering pad #3 on the back of the SparkFun serial controlled motor driver.
Your completed Serial Controlled motor drive should look somewhat similar to the board shown below.
Break off 5 Male PTH straight headers and solder into the breakout points on the SparkFun microB USB Breakout. Install these boards on the included mini breadboard so the "GRD" terminals for each unit share a bridge on one side of the breadboard. Utilize the included "2 in - 22 gauge solid core hookup wire (red)" to bridge the "VCC" pin for the SparkFun microB Breakout to the either (VIN) connection point on the SparkFun Serial Controlled Motor Driver.
Utilize a small flat head screwdriver to loosen the four connection points on the screw terminals you soldered to the motor connection points on the SparkFun Serial Controlled motor driver. When inserting the motor connection wires, note the desired output given the caution noted in section #1 of this assembly guide. Note from section #1: Do not worry about the motor orientation as you will determine proper motor operation in how you connect the motor leads to the SparkFun Serial Controlled Motor Driver. These connection points can be corrected when testing the robot functionality if it goes straight when you expect Jetbot to turn or vice versa.
Set this assembly aside for full installation later.
4. Accessory installation to main chassis
Align the mounting holes on the SparkFun Micro OLED (Qwiic) with those on the back of the SparkFun Jetbot acrylic mounting plate. Install the Micro OLED using two 1/4 in 4-40 Phillips head screws and two 4-40 machine screw nuts.
Thread the ribbon cable of the Leopard imaging camera back through the acrylic mounting plate and half-helix towards the left side of the Jetbot.
Install the Jetson Nano Dev kit to the nylon standoffs using 4x 1/4 in 4-40 Phillips head screws. Tighten each screw slightly in a criss-cross pattern to ensure the through holes do not bind during install until finger tight. Make sure you can still access the camera ribbon cable.
Unpackage & install the USB Wifi adaptor into one of the USB ports on the Jetson nano Dev Kit. The drivers for this Wifi adaptor are pre-installed on the SparkFun Jetbot image. If you are making your own image, you will need to ensure you get these from Edimax.
Wrap the motor wires around the rear/left standoff to take up some of the slack; one or two passes should do. Peel the cover off the self adhesive backing on the mini breadboard you set aside at the end of section #3.
Daisy chain the polarized Qwiic connector into the back of the SparkFun Micro OLED (Qwiic). Using the 100mm Qwiic Cable attach the SparkFun Micro OLED front Qwiic connector to the SparkFun pHat; as shown in the next two pictures.
Cut the Dual Lock Velcro into to pieces and align them on the 10Ah battery & top plate of the Two-Layer Circular Robotics Chassis as shown below. Ensure that the USB ports on the battery pack are pointing out the back of the Jetbot. Additionally, the orange port (3A) will need to power the Jetson Nano Dev Kit & therefore will need to be on the right side of the Jetbot.
The orange port (3A) is used to power the Jetson Nano Dev Kit. Utilize the remaining of the 6 in micro-B USB cables to bridge this power gap.
5. Software setup guide from NVIDIA
Your SparkFun Jetbot comes with a Pre-Flashed micro SD card. Step 1 of the following link talks about how to flash your SD card, so feel free to skip to "Step 2 - Boot Jetson Nano."
LINK: NVIDIA Jetbot Wiki Software Setup
6. Examples
LINK: NVIDIA Jetbot Wiki Examples
learn.sparkfun.com | CC BY-SA 3.0 | SparkFun Electronics | Niwot, Colorado