Trouble building your XRP from Sparkfun? Here is a step by step set of instructions and resources including links to videos, part lists, and downloadable 3D files
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XRP Robotics Platform Kit - Unboxing Video | DigiKey
Robot Chassis & Robot Controller
The XRP kit 1568-KIT-22296-ND uses a single piece chassis to hold each robot component and utilizes a rail system that is designed to make it easier to add additional components and can do so without any tools. Each part or component that comes with the XRP kit can snap onto the chassis for simple assembly, 3D printing your own parts is also an option.
This kit utilizes part number 1568-ROB-22727-ND which uses a RP2040 microprocessor to drive the motors, read sensor inputs and also runs Python/Blockly programs. This microprocessor also has additional components that sense and measure accelerations and headings of the robot but also enables Wifi communication.
Assembly of the XRP kit can be done without the use of tools, the only exception to this is if you want to screw in the servo arm attachment, which is optional. The complete assembly process from start to finish should take approximately 15 minutes, it might be helpful to view the Sparkfun assembly video before putting the kit together.
Insert the controller board into the chassis as shown below. The connector of the battery should be facing the back of the robot. Partially insert the top corners of the controller board into to the corners (1 & 2) as shown below. There are also 2 clips (3 & 4) in the bottom of this that are designed to hold the board in place. Push down and forward on the back of the board so that the corners are completely seated in the corner pockets (1 & 2) and the bottom corners of the board (3 & 4) snap into place.
Battery Case Installation
A battery case, 1568-1407-ND, is used to provide power to the robot and holds 4 AA batteries. You can use standard alkaline or rechargeable batteries.
On the bottom of the chassis there is a cut out designed to hold the battery pack in place. First, insert the cable through the cutout in the chassis and feed that to the other side.
Next, put the battery pack in the slot up against the fingers designed to hold it in place, push the edge of the battery pack until it is completely seated.
The battery pack cover can be added by just lining up the two tabs on the cover to the two slots in the chassis just outside the battery case, once pushed the cover should snap into place.
Tires, Wheels, and Motors
Casters Wheels
These Casters, part number 1568-PRT-24050-ND, can be installed in the front of the robot and provide a low-friction contact point for the robot. There are two round slots that are designed to hold the caster (balls) in place. Simply insert the caster into the slow and push down to snap them in place, once installed the casters should rotate freely.
Wheels/O-ring Tires
1568-PRT-24051-ND is the part number for these O-rings that slip over the plastic wheels provided. They give the robot more traction, especially on smooth surfaces.
This can be simply done by slipping the tire into the groove on the outside rim of the wheel and stretch it into place.
Drive Motor Installation
Two motors are provided with the part number 1568-ROB-24053-ND and are responsible for driving the robot. These motors include encoders to make it easier to program the robot for specific distances and speeds. This provides more control and accuracy when programming the robot. These can be attached to the controller board using the included cables.
Notice that there are 2 flat sides on the shaft of the drive motor that correspond to the flat edges of the center of the wheel. Another thing to look for when installing the wheel on the drive motor is that the wheels have 1 side that is completely flat, this side needs to be facing away from the motor when installed.
The motor cable connection enables you to drive the motors and also receive data from the motor encoder sensors that provide position and speed info for you robot program.
The wider connector on the cable is inserted into the motor. Notice that pins (wires) on the motor connector are closer to one side than the other. Similarly, the holes on the connector attached to the cable are closer to one side.
Once you have installed the tires and wheels, the drive motors can be installed into designated cutouts that are on the bottom of the chassis. When placing the motor in the designated slot, it is helpful to pass the cable assembly through first. The wheel should be facing the outside of the chassis when installed the wheel should go through the designated cutout slot. Once you have the notch on the drive motor inserted into the slot of the chassis, apply pressure on the drive motor (away from the cable end) and press down. This should lock the drive motor into place, repeat for both motors.
There are designated sections on the controller board that are labeled ‘Motor L’ and ‘Motor R’, each drive motor can be connected to the corresponding connector. To make sure the connectors are orientated correctly by ensuring that the “ML+” pin is matching up with the red wire and the “ML-“ is matching up with the black wire.
Sensors
The XRP uses a 1568-SEN-24048-ND line following sensor that detect lines on the driving surface that have different reflectivity. There are 2 LED’s a photosensors to emit infrared light and then measures the reflective brightness. These can be used to monitor whenever the sensor detects that the robot has gone past the left or right threshold when performing line following experiments.
The part number 3647-HC-SR04-ND is the ultrasonic sensor that uses sound to measure distance in front of the robot and detect any objects. This sensor is 4 position, Vcc (red), Gnd (black), Trig (blue) and Echo (yellow). The Trig and Echo are responsible for operating the sensor and get range data.
The line following sensor (reflectance) and rangefinder sensor can be connected as shown in the pictures below. The individual connectors simply can be pressed onto the corresponding sensor pins. Make sure you have the correct order and color of the wires and make sure the wires are fully seated to ensure a good connection.
Sensor Brackets
The reflectance sensor bracket can be installed by inserting the ball end of the bracket into the slot on the front rail of the chassis:
Sensor Installation
The sensors can be installed as shown below:
Both sensors can be connected to the controller board into their designated connectors. The reflectance sensor (line follower) will plug into the connector called “Line” and the Ultrasonic sensor (rangefinder) can be plugged into he connector labeled “Range”. To minimize extra wires and reduce the chances of getting snagged on something, it is helpful to tuck a small loop of wire into the chassis as shown below.
Servo Motor, Arm and Bracket
The XRP comes with a servo motor and an arm that you can attach to the robot and programmed to perform specific actions. This is a special type of servo motor where you can program it so it will automatically move to a predetermined angle.
The servo motor is used to rotate the servo arm to a desired position and can be attached to the back of the chassis. First, insert the ball of the servo bracket into the upper slot on the back rail of the chassis, then snap the bottom part of the bracket over the bottom edge of the chassis as shown below.
The servo cable is connected to the designated connector labeled “Servo 1” on the controller board. Make sure the connector is facing the correct orientation so that the black wire is going to “GND”, the red wire is going to “5V” and the white wire is going to “IO17”.
The kit comes with serval servo “horns” that can attach to the servo arm for a variety of expansion projects. Be sure to install the servo horn so that the mounting flange is facing the correct direction.
Servo Arm
The servo arm is pressure fitted onto the white shaft of the servo motor. Keep in mind that the servo motor only has 180 degrees of rotation so make sure to install so that the arm has a full range of motion (180 degrees) from front to back and is not restricted by the chassis
| MFR PART # | KIT-22296 |
|---|---|
| DIGIKEY PART # | 1568-KIT-22296-ND |
| MANUFACTURER | SparkFun Electronics |
| DESCRIPTION | Robotics Kit |
| DATASHEET | Click Here |
| MFR PART # | ROB-22727 |
|---|---|
| DIGIKEY PART # | 1568-ROB-22727-ND |
| MANUFACTURER | SparkFun Electronics |
| DESCRIPTION | Raspberry Pi Pico Python Controller Robotics Kit |
| DATASHEET | Click Here |
| MFR PART # | HC-SR04 |
|---|---|
| DIGIKEY PART # | 3647-HC-SR04-ND |
| MANUFACTURER | UNIVERSAL-SOLDER Electronics Ltd |
| DESCRIPTION | Ultrasonic Sensor 40kHz |
| DATASHEET | Click Here |
| MFR PART # | SEN-24048 |
|---|---|
| DIGIKEY PART # | 1568-SEN-24048-ND |
| MANUFACTURER | SparkFun Electronics |
| DESCRIPTION | QRE1113GR Line Follower Sensor Platform Evaluation Expansion Board |
| DATASHEET | Click Here |
| MFR PART # | PRT-24051 |
|---|---|
| DIGIKEY PART # | 1568-PRT-24051-ND |
| MANUFACTURER | SparkFun Electronics |
| DESCRIPTION | O-RING (2-PACK) |
| DATASHEET | Click Here |
| MFR PART # | ROB-24053 |
|---|---|
| DIGIKEY PART # | 1568-ROB-24053-ND |
| MANUFACTURER | SparkFun Electronics |
| DESCRIPTION | Continuous Rotation DC Motor Servomotor, RC (Hobby) 140 RPM Incremental 4.5 ~ 9VDC |
| DATASHEET | Click Here |
| MFR PART # | ROB-24052 |
|---|---|
| DIGIKEY PART # | 1568-ROB-24052-ND |
| MANUFACTURER | SparkFun Electronics |
| DESCRIPTION | Positional Rotation DC Motor Servomotor, RC (Hobby) 4.8 ~ 6VDC |
| DATASHEET | Click Here |
| MFR PART # | PRT-24050 |
|---|---|
| DIGIKEY PART # | 1568-PRT-24050-ND |
| MANUFACTURER | SparkFun Electronics |
| DESCRIPTION | CASTER (2-PACK) |
| DATASHEET | Click Here |
| MFR PART # | PRT-09835 |
|---|---|
| DIGIKEY PART # | 1568-1407-ND |
| MANUFACTURER | SparkFun Electronics |
| DESCRIPTION | Battery Holder (Open) AA 4 Cell Barrel Plug, 2.1mm I.D. x 5.5mm O.D. |
| DATASHEET | Click Here |
| MFR PART # | PRT-12796 |
|---|---|
| DIGIKEY PART # | 1568-1513-ND |
| MANUFACTURER | SparkFun Electronics |
| DESCRIPTION | Jumper Wire Female to Female 6.00" (152.40mm) 28 AWG |
| DATASHEET | Click Here |
