The SDS011 sensor determines the dust particle concentration in the air using the scattered light method.
The USB-UART adapter also allows the sensor to be read out directly via USB port on a computer.
Specifications
Interface
UART (3.3 V level)
Resolution
0.3 µg/m3
Response time
< 10s
Other feature
Integrated fan
Current in idle
< 4 mA
Supply current
70 mA
Operating voltage
5 V
Dimensions
70 x 70 x 24 mm
Weight
70 g
Included
1x SDS011 dust sensor
1x Connection cable
1x USB-UART adapter
Downloads
Datasheet
Manual
These are some of our favourite sensors from each category. But wait, there's more! The SparkFun Sensor Kit now includes several of our sensor boards that feature the Qwiic Connect System for rapid prototyping!
This version of the kit has received a complete overhaul!
This huge assortment of sensors makes an amazing gift for that exceptional electronics enthusiast in your life!
Included
Large Piezo Vibration Sensor (With Mass): A flexible film able to sense for vibration, touch, shock, etc. When the film moves back and forth an AC wave is created, with a voltage of up to ±90.
Reed Switch: Senses magnetic fields, makes for a great non-contact switch.
0.25' Magnet Square: Plays nicely with the reed switch. Embed the magnet into stuffed animals or inside a box to create a hidden actuator to the reed switch.
0.5' Force Sensitive Resistor: A force-sensing resistor with a 0.5' diameter sensing area. Great for sensing pressure (i.e., if it's being squeezed).
Flex Sensor (2.2'): As the sensor is flexed, the resistance across the sensor increases. Useful for sensing motion or positioning.
SoftPot: These are very thin variable potentiometers. By pressing on various positions along the strip, you vary the resistance.
Mini Photocell: The photocell will vary its resistance based on how much light it's exposed to. Will vary from 1kΩ in the light to 10kΩ in the dark.
PIR Motion Sensor: Easy-to-use motion detector with an analog interface. Power it with 5-12VDC, and you'll be alerted of any movement.
QRD1114 Optical Detector/Phototransistor: An all-in-one infrared emitter and detector. Ideal for sensing black-to-white transitions or can be used to detect nearby objects.
IR Diode: This LED can handle up to 50mA of current and outputs in the 940-950nm IR spectrum. Use to send signal to talk to the included IR receiver diode or just turn off your neighbor's TV.
IR Receiver Diode: This simple IR receiver will detect an IR signal coming from a standard IR remote control or the IR diode included in the kit.
Resistor 1.0M Ohm 1/4 Watt PTH: Two 1/4 Watt, +/- 5% tolerance PTH resistors. Commonly used in breadboards and perf boards. The large resistor helps dampen any voltage spikes when using the large piezo vibration sensor with a microcontroller.
Resistor 10K Ohm 1/4 Watt PTH – 20 pack (Thick Leads): 1/4 Watt, +/- 5% tolerance PTH resistors. Commonly used in breadboards and perf boards, these 10KΩ resistors make excellent pullups, pulldowns, and current limiters.
Resistor 330 Ohm 1/4 Watt PTH – 20 pack (Thick Leads): 1/4 Watt +/- 5% tolerance PTH resistors. Commonly used in breadboards and perf boards, these 330Ω resistors make excellent current-limiting resistors for LEDs.
SparkFun 9DoF IMU Breakout – ISM330DHCX, MMC5983MA (Qwiic): This breakout board includes a 3-axis accelerometer, 3-axis gyroscope, and 3-axis magnetometer. Connect this board over I2C using a Qwiic cable or solder wires or headers to the SPI pins to get started using one of the three sensors or using all three together to determine 3D orientation.
SparkFun Atmospheric Sensor Breakout – BME280 (Qwiic): The SparkFun BME280 Atmospheric Sensor Breakout is an easy way to measure barometric pressure, humidity, and temperature readings, all without taking up too much space.
SparkFun Indoor Air Quality Sensor – ENS160 (Qwiic): The SparkFun ENS160 Indoor Air Quality Sensor is a digital multi-gas sensor solution with four sensor elements that can be used in a wide range of applications including building automation, smart home, and HVAC.
SparkFun Capacitive Touch Slider – CAP1203 (Qwiic): This little board acts great as a non-mechanical button. Use the three pads on the board or connect your own input for a great touch button or slider with no moving parts.
Flexible Qwiic Cable (100 mm): Use these to connect up to four Qwiic boards in your kit.
RGB and Gesture Sensor (APDS-9960): This board does a little bit of everything. You can measure ambient light or color as well as detect proximity and do gesture sensing all over I2C.
Soil Moisture Sensor (with screw terminals): Ever wonder if your plant needs water? This sensor outputs an analog signal based on the resistance of the soil. Since water is conductive, the soil water content will be reflected in the soil resistance.
Sound Detector: Ever need to know if there is noise in an area? This board will not only tell you, but it will also output amplitude as well as the full audio signal.
Break Away Headers (Straight): Solder these pins to any of the breakouts to prototype on a breadboard. You'll want to solder these to boards that do not have Qwiic connectors such as the gesture sensor and sound detector.
40+ Projects using Arduino, Raspberry Pi and ESP32
This book is about developing projects using the sensor-modules with Arduino Uno, Raspberry Pi and ESP32 microcontroller development systems. More than 40 different sensors types are used in various projects in the book. The book explains in simple terms and with tested and fully working example projects, how to use the sensors in your project. The projects provided in the book include the following:
Changing LED brightness
RGB LEDs
Creating rainbow colours
Magic wand
Silent door alarm
Dark sensor with relay
Secret key
Magic light cup
Decoding commercial IR handsets
Controlling TV channels with IT sensors
Target shooting detector
Shock time duration measurement
Ultrasonic reverse parking
Toggle lights by clapping hands
Playing melody
Measuring magnetic field strength
Joystick musical instrument
Line tracking
Displaying temperature
Temperature ON/OFF control
Mobile phone-based Wi-Fi projects
Mobile phone-based Bluetooth projects
Sending data to the Cloud
The projects have been organized with increasing levels of difficulty. Readers are encouraged to tackle the projects in the order given. A specially prepared sensor kit is available from Elektor. With the help of this hardware, it should be easy and fun to build the projects in this book.
This bundle contains:
Book: Building Wireless Sensor Networks with OpenThread (normal price: €40)
Nordic Semiconductor nRF52840 USB Dongle (normal price: €20)
Book: Building Wireless Sensor Networks with OpenThread
This book will guide you through the operation of Thread, the setup of a Thread network, and the creation of your own Zephyr-based OpenThread applications to use it. You’ll acquire knowledge on:
The capture of network packets on Thread networks using Wireshark and the nRF Sniffer for 802.15.4.
Network simulation with the OpenThread Network Simulator.
Connecting a Thread network to a non-Thread network using a Thread Border Router.
The basics of Thread networking, including device roles and types, as well as the diverse types of unicast and multicast IPv6 addresses used in a Thread network.
The mechanisms behind network discovery, DNS queries, NAT64, and multicast addresses.
The process of joining a Thread network using network commissioning.
CoAP servers and clients and their OpenThread API.
Service registration and discovery.
Securing CoAP messages with DTLS, using a pre-shared key or X.509 certificates.
Investigating and optimizing a Thread device’s power consumption.
Once you‘ve set up a Thread network with some devices and tried connecting and disconnecting them, you’ll have gained a good insight into the functionality of a Thread network, including its self-healing capabilities. After you’ve experimented with all code examples in this book, you’ll also have gained useful programming experience using the OpenThread API and CoAP.
Nordic Semiconductor nRF52840 USB Dongle
The nRF52840 dongle is a small, low-cost USB dongle that supports Bluetooth 5.3, Bluetooth mesh, Thread, ZigBee, 802.15.4, ANT and 2.4 GHz proprietary protocols. The dongle is the perfect target hardware for use with nRF Connect for Desktop as it is low-cost but still support all the short range wireless standards used with Nordic devices.
The dongle has been designed to be used as a wireless HW device together with nRF Connect for Desktop. For other use cases please do note that there is no debug support on the dongle, only support for programming the device and communicating through USB.
It is supported by most of the nRF Connect for Desktop apps and will automatically be programmed if needed. In addition custom applications can be compiled and downloaded to the dongle. It has a user programmable RGB LED, a green LED, a user programmable button as well as 15 GPIO accessible from castellated solder points along the edge. Example applications are available in the nRF5 SDK under the board name PCA10059.
The nRF52840 dongle is supported by nRF Connect for Desktop as well as programming through nRFUtil.
Features
Bluetooth 5.2 ready multiprotocol radio
2 Mbps
Long Range
Advertising Extensions
Channel Selection Algorithm #2 (CSA #2)
IEEE 802.15.4 radio support
Thread
ZigBee
Arm Cortex-M4 with floating point support
DSP instruction set
ARM CryptoCell CC310 cryptographic accelerator
15 GPIO available via edge castellation
USB interface direct to nRF52840 SoC
Integrated 2.4 GHz PCB antenna
1 user-programmable button
1 user-programmable RGB LED
1 user-programmable LED
1.7-5.5 V operation from USB or external
Downloads
Datasheet
Hardware Files
Pixy2 can be taught to detect objects by the press of a button. It is equipped with a new line detection algorithm to use on line-following robots. It can learn to recognize intersection and follow road signs.
Pixy2 comes with various cables so that you can connect it with an Arduino or a Raspberry Pi out of the box. Furthermore, the I/O port offers several interfaces (SOI, I²C, UART, USB) to plug your Pixy2 in most boards.
Downloads
Documentation
Projects
Software
Developing CoAP applications for Thread networks with Zephyr
This book will guide you through the operation of Thread, the setup of a Thread network, and the creation of your own Zephyr-based OpenThread applications to use it. You’ll acquire knowledge on:
The capture of network packets on Thread networks using Wireshark and the nRF Sniffer for 802.15.4.
Network simulation with the OpenThread Network Simulator.
Connecting a Thread network to a non-Thread network using a Thread Border Router.
The basics of Thread networking, including device roles and types, as well as the diverse types of unicast and multicast IPv6 addresses used in a Thread network.
The mechanisms behind network discovery, DNS queries, NAT64, and multicast addresses.
The process of joining a Thread network using network commissioning.
CoAP servers and clients and their OpenThread API.
Service registration and discovery.
Securing CoAP messages with DTLS, using a pre-shared key or X.509 certificates.
Investigating and optimizing a Thread device’s power consumption.
Once you‘ve set up a Thread network with some devices and tried connecting and disconnecting them, you’ll have gained a good insight into the functionality of a Thread network, including its self-healing capabilities. After you’ve experimented with all code examples in this book, you’ll also have gained useful programming experience using the OpenThread API and CoAP.
40+ Projects using Arduino, Raspberry Pi and ESP32
This book is about developing projects using the sensor-modules with Arduino Uno, Raspberry Pi and ESP32 microcontroller development systems. More than 40 different sensors types are used in various projects in the book. The book explains in simple terms and with tested and fully working example projects, how to use the sensors in your project. The projects provided in the book include the following:
Changing LED brightness
RGB LEDs
Creating rainbow colours
Magic wand
Silent door alarm
Dark sensor with relay
Secret key
Magic light cup
Decoding commercial IR handsets
Controlling TV channels with IT sensors
Target shooting detector
Shock time duration measurement
Ultrasonic reverse parking
Toggle lights by clapping hands
Playing melody
Measuring magnetic field strength
Joystick musical instrument
Line tracking
Displaying temperature
Temperature ON/OFF control
Mobile phone-based Wi-Fi projects
Mobile phone-based Bluetooth projects
Sending data to the Cloud
The projects have been organized with increasing levels of difficulty. Readers are encouraged to tackle the projects in the order given. A specially prepared sensor kit is available from Elektor. With the help of this hardware, it should be easy and fun to build the projects in this book.
Maker Line is a line sensor with 5 x IR sensors array that is able to track line from 13 mm to 30 mm width. The sensor calibration is also simplified. There is no need to adjust the potentiometer for each IR sensor. You just have to press the calibrate button for 2 seconds to enter calibration mode. Afterwards you need to sweep the sensors array across the line, press the button again and you are good to go. The calibration data is saved in EEPROM and it will stay intact even if the sensor has been powered off. Thus, calibration only needs to be carried out once unless the sensor height, line color or background color has changed. Maker Line also supports dual outputs: 5 x digital outputs for the state of each sensor independently, which is similar to conventional IR sensor, but you get the benefit of easy calibration, and also one analog output, where its voltage represents the line position. Analog output also offers higher resolution compared to individual digital outputs. This is especially useful when high accuracy is required while building a line following robot with PID control. Features Operating Voltage: DC 3.3 V and 5 V compatible (with reverse polarity protection) Recommended Line Width: 13 mm to 30 mm Selectable line color (light or dark) Sensing Distance (Height): 4 mm to 40 mm (Vcc = 5 V, Black line on white surface) Sensor Refresh Rate: 200 Hz Easy calibration process Dual Output Types: 5 x digital outputs represent each IR sensor state, 1 x analog output represents line position. Support wide range of controllers such as Arduino, Raspberry Pi etc. Documentation Datasheet Tutorial: Building A Low-Cost Line Following Robot
Build your textbook weather station or conduct environmental research together with the whole world. With many practical projects for Arduino, Raspberry Pi, NodeMCU, ESP32, and other development boards.
Weather stations have enjoyed great popularity for decades. Every current and even every long discontinued electronics magazine has regularly featured articles on building your own weather station. Over the years, they have become increasingly sophisticated and can now be fully integrated into an automated home — although this often requires loyalty to an (expensive) brand manufacturer across all components.
With your own weather and environmental data, you can keep up and measure things that no commercial station can. It’s also fun: expand your knowledge of electronics, current microcontroller development boards and programming languages in a fun and meaningful way. For less than 10 euros you can get started and record your first environmental data — with time and growing interest, you will continue to expand your system.
In this Edition
Which Microcontroller Fits My Project?
The Right Development Environment
Tracking Wind and Weather
Weather Display with OpenWeatherMap and Vacuum Fluorescent Display
Volatile Organic Compounds in the Air We Breathe
Working with MQ Sensors: Measuring Carbon Monoxide — Odorless but Toxic
CO2 Traffic Light with ThingSpeak IoT Connection
An Automatic Plant Watering System
Good Indoor Climate: Temperature and Humidity are Important criteria
Classy Thermometer with Vintage Tube Technology
Nostalgic Weather House for the Whole Family
Measuring Air Pressure and Temperature Accurately
Sunburn Warning Device
DIY Sensor for Sunshine Duration
Simple Smartphone Says: Fog or Clear View?
Identifying Earthquakes
Liquid Level Measurement for Vessels and Reservoirs
Water pH Value Measurement
Detecting Radioactive Radiation
GPS: Sensor Location Service Across the Globe
Saving and Timestamping Log Files on SD Cards
LoRaWAN, The Things Network, and ThingSpeak
Operating a LoRaWAN Gateway for TTN
Defying "Wind and Weather"
Mega Display with Weather Forecasz
The JOY-iT R301T fingerprint sensor module is capable of image collection and algorithm calculation due to this integrated chip. Another remarkable function of the sensor is, that it can recognize the fingerprint in different conditions, for example humidity, light texture or changes of the skin. This offers a very wide range of possible applications to secure locks and doors among others. The chip can send data via UART, TTL serial and USB to the connected controller.
Specifications
Model
JP2000 sensor
Chip
32 Bit ARM Cortex-M3
Chip storage
96 kB RAM, 1 MB Flash
Power supply
4.2-6.0 V
Working current
Typical: 40 mAPeak: 50 mA
Logic level
3,3/5 V TTL Logic
Fingerprint storage capacity
3000 Prints
Matching mode
1:N Identification1:1 Verification
Adjustable security level
1 - 5 levels(default security level: 3)
False acceptance rate
< 0.001%(on security level 3)
False acceptance rate
< 0.1%(on security level 3)
Response time
Pre-treatment: < 0.45 sMatch: < 1.5 s
Baud rate support
9600 - 921600
UART communication
No parity, Stop Bit: 1
Dimensions
42 x 19 x 8 mm
Included
1x Fingerprint sensor COM-FP-R301T
1x Cable
Downloads
Datasheet
Manual
Temporary Delay in the Delivery of Unitree Robots
Like many other suppliers, we are currently experiencing delays in the delivery of Unitree robots. A shipment from our supplier is currently held in customs, which has unfortunately led to later-than-planned deliveries for previously placed orders. We are actively working with our supplier to resolve this issue and expect more clarity soon, but at this time, we cannot provide any guarantees.
Additionally, a new shipment is already on its way, though it will take some time to arrive. Since other suppliers are facing similar challenges, switching to a different provider is unlikely to result in a faster solution. Our top priority remains fulfilling existing orders.
If you have any questions or would like to update your order, please do not hesitate to contact our customer service team. We will keep you informed of any further developments.
Unitree Go2 series consists of quadruped robots for the research & development of autonomous systems in the fields of human-robot interaction (HRI), SLAM & transportation. Due to the four legs, as well as the 12DOF, this robot can handle a variety of different terrains. The Go2 comes with a perfected drive & power management system, which enables a speed (depending on the version) of up to 3.7 m/s or 11.88 km/h with an operating time of up to 4 hours. Furthermore, the motors have a torque of 45 N.m at the body/thighs and at the knees, which also allow jumps or backflips.
Features
Super Recognition System: 4D LIDAR L1
Max Running Speed: approx. 5 m/s
Peak Joint Torque: approx. 45 N.m
Wireless Module: WiFi 6/Bluetooth/4G
Ultra-long battery Endurance: approx. 2-4 h (long battery life measured in real life)
Intelligent Side-follow System: ISS 2.0
Specifications
Tracking module: Remote-controlled or automatic tracking
Front camera: Image tansmission Resolution 1280x720, FOV 120°, Ultra wide angle lens deliver rich clarity
Front lamp: Brightly lights the way ahead
4D LiDAR L1: 360°x90° omnidirectional ultra-wide-angle scanning allows automatic avoidance with small blind spot and stable operation
12 knee joint motors: Strong and powerful, Beautiful and simple, Brandy new visual experience
Intercom microphone: Effective communication with no scenario restrictions
Self-retracting strap: Easy to carry and load things
More stable, more powerful with advanced devices: 3D LiDAR, 4G ESIM Card, WiFi 6 with Dual-band, Bluetooth 5.2 for stable connection and remote control
Powerful Computing Core: Motion controller, High-performance ARM processor, Improved Al algorithm processor, External ORIN NX/NANO
Smart battery: Standard 8000 mAh battery, Long-endurance 15000 mAh battery, Protection from over-temp, overcharge and short-circuit
Speaker for music play: Listen to music as your pleasure
Unitree Go2 Variants
The Go2 impresses not only with its technical capabilities, but also with a modern and slim design that gives it a futuristic look and makes it a real eye-catcher. The Go2 Air is specially designed for demos and presentations. With its basic features, it offers a solid basis for demonstrating the movement capabilities and functionality of a four-legged robot. Important: The Go2 Air is delivered without a controller. This can be purchased optionally.
With a powerful 8-core high-performance CPU, the Pro and Edu offer impressive computing power required for complex tasks and demanding calculations. This enables faster and more efficient data processing and makes the Pro and Edu a reliable partner for your projects.
From the Edu version onwards, the Go2 is programmable and opens up endless possibilities for developing and researching your own robotics applications. The Go2 is also able to handle a step height of up to 14 cm. This makes it an ideal tool for research, education and entry into the world of robotics.
The Go2 Edu comes with a remote controller that gives you easy and intuitive control. You also get a docking station with impressive computing power of 100 TOPS, which is equipped with powerful AI algorithms and offers you technical support.
Go2 Edu is equipped with a powerful 15000 mAh battery that gives it an impressive runtime of up to 4 hours. This long operating time allows the robot to carry out longer exploration missions and complete demanding tasks.
Model Comparison
Air
Pro
Edu/Edu Plus
Dimensions (standing)
70 x 31 x 40 cm
70 x 31 x 40 cm
70 x 31 x 40 cm
Dimensions (crouching)
76 x 31 x 20 cm
76 x 31 x 20 cm
76 x 31 x 20 cm
Material
Aluminium alloy + High strength engineering plastic
Aluminium alloy + High strength engineering plastic
Aluminium alloy + High strength engineering plastic
Weight (with battery)
about 15 kg
about 15 kg
about 15 kg
Voltage
28~33.6 V
28~33.6 V
28~33.6 V
Peaking capacity
about 3000 W
about 3000 W
about 3000 W
Payload
≈7 kg (MAX ~ 10 kg)
≈8 kg (MAX ~ 10 kg)
≈8 kg (MAX ~ 12 kg)
Speed
0~2.5 m/s
0~3.5 m/s
0~3.7 m/s (MAX ~ 5 m/s)
Max Climb Drop Height
about 15 cm
about 16 cm
about 16 cm
Max Climb Angle
30°
40°
40°
Basic Computing Power
N/A
8-core High-performance CPU
8-core High-performance CPU
Aluminum knee joint motor
12 set
12 set
12 set
Intra-joint circuit (knee)
✓
✓
✓
Joint Heat Pipe Cooler
✓
✓
✓
Range of Motion
Body: −48~48°
Body: −48~48°
Body: −48~48°
Thigh: −200°~90°
Thigh: −200°~90°
Thigh: −200°~90°
Shank: −156°~−48°
Shank: −156°~−48°
Shank: −156°~−48°
Max Torque
N/A
about 45 N.m
about 45 N.m
Super-wide-angle 3D LiDAR
✓
✓
✓
Wireless Vector Positioning Tracking Module
N/A
✓
✓
HD Wide-angle Camera
✓
✓
✓
Foot-end force sensor
N/A
N/A
✓
Basic Action
✓
✓
✓
Auto-scaling strap
N/A
✓
N/A
Upgraded Intelligent OTA
✓
✓
✓
RTT 2.0 Image Transmission
✓
✓
✓
App Basic Remote Control
✓
✓
✓
App Data Viewing
✓
✓
✓
App Graphical Programme
✓
✓
✓
Front Lamp (3 W)
✓
✓
✓
WiFi 6 with Dual-band
✓
✓
✓
Bluetooth 5.2/4.2/2.1
✓
✓
✓
4G Module
N/A
CN/GB
CN/GB
Voice Function
N/A
✓
✓
Music Playback
N/A
✓
✓
ISS 2.0 Intelligent side-follow system
N/A
✓
✓
Intelligent detection and avoidance
✓
✓
✓
Secondary development
N/A
N/A
✓
Manual controller
Optional
Optional
✓
High computing power module
N/A
N/A
Edu: 40 TOPS computing power
Edu Plus: 100 TOPS computing power
NVIDIA Jetson Orin (optional)
Smart Battery
Standard (8000 mAh)
Standard (8000 mAh)
Long endurance (15000 mAh)
Battery Life
1-2 h
1-2 h
2-4 h
Charger
Standard (33.6 V, 3.5 A)
Standard (33.6 V, 3.5 A)
Fast charge (33.6 V, 9 A)
Included
1x Unitree Go2 Air
1x Unitree Go2 Battery (8000 mAh)
Downloads
Documentation
iOS/Android apps
GitHub
Build your textbook weather station or conduct environmental research together with the whole world. With many practical projects for Arduino, Raspberry Pi, NodeMCU, ESP32, and other development boards.
Weather stations have enjoyed great popularity for decades. Every current and even every long discontinued electronics magazine has regularly featured articles on building your own weather station. Over the years, they have become increasingly sophisticated and can now be fully integrated into an automated home — although this often requires loyalty to an (expensive) brand manufacturer across all components.
With your own weather and environmental data, you can keep up and measure things that no commercial station can. It’s also fun: expand your knowledge of electronics, current microcontroller development boards and programming languages in a fun and meaningful way. For less than 10 euros you can get started and record your first environmental data — with time and growing interest, you will continue to expand your system.
In this Edition
Which Microcontroller Fits My Project?
The Right Development Environment
Tracking Wind and Weather
Weather Display with OpenWeatherMap and Vacuum Fluorescent Display
Volatile Organic Compounds in the Air We Breathe
Working with MQ Sensors: Measuring Carbon Monoxide — Odorless but Toxic
CO2 Traffic Light with ThingSpeak IoT Connection
An Automatic Plant Watering System
Good Indoor Climate: Temperature and Humidity are Important criteria
Classy Thermometer with Vintage Tube Technology
Nostalgic Weather House for the Whole Family
Measuring Air Pressure and Temperature Accurately
Sunburn Warning Device
DIY Sensor for Sunshine Duration
Simple Smartphone Says: Fog or Clear View?
Identifying Earthquakes
Liquid Level Measurement for Vessels and Reservoirs
Water pH Value Measurement
Detecting Radioactive Radiation
GPS: Sensor Location Service Across the Globe
Saving and Timestamping Log Files on SD Cards
LoRaWAN, The Things Network, and ThingSpeak
Operating a LoRaWAN Gateway for TTN
Defying "Wind and Weather"
Mega Display with Weather Forecasz
