EXPANSION HUB REV ROBOTICS - EXPANSION HUB revrobotics.com ANOTHER - - PowerPoint PPT Presentation

Introduction to the

EXPANSION HUB

REV ROBOTICS - EXPANSION HUB

revrobotics.com

MODERN ROBOTICS REV ROBOTICS

ANOTHER CONTROLLER CHOICE

The Expansion hub does not replace the Modern Robotics System. It is just another option for teams to use.

REV ROBOTICS MAKES TWO HUBS

ONLY ONE IS FTC LEGAL

Control Hub Expansion Hub

FIRST TECH CHALLENGE FIRST GLOBAL CHALLENGE

EXPANSION HUB PORTS

ANALOG AND DIGITAL PORTS NEED A SPLITTER TO USE THEM ALL

2 Analog become 4 4 Digital become 8

Do NOT use the splitter on the I2C ports

2/$3

INTEGRATED SENSORS

• Battery voltage monitoring
• Integrated Bosch BNO055 9-Axis absolute orientation IMU sensor
• Current Monitoring [Not Available in Ver 3.1]
• Battery
• I2C Bus
• Servo Bus
• Digital Bus
• Individual Motor Channel Current Monitoring and Control [Not

Available in Ver 3.1]

NEED MORE PORTS?

Two Expansion Hubs are allowed

SIZE COMPARISON

MODERN ROBOTICS REV ROBOTICS

COST COMPARISON – 4 MOTORS, 6 SERVOS

$90 Power Distribution Module $160 Motor Controller Module $70 Servo Controller Module $68 Device Interface Module $33 Integrated Gyro $33 Compass/Accelerometer

$454 Total

$150 REV Robotics Expansion Hub $12 Level Shifters for motor encoders $30 Additional cables, etc.

$192 Total (with Team Discount) Modern Robotics REV Robotics

COST COMPARISON – 8 MOTORS, 12 SERVOS

$90 Power Distribution Module (1) $320 Motor Controller Modules (4) $140 Servo Controller Modules (2) $68 Device Interface Module (1) $33 Integrated Gyro (1) $33 Compass/Accelerometer (1)

$684 Total

$300 REV Robotics Expansion Hub (2) $24 Level Shifters for motor encoders $60 Additional cables, etc.

$384 Total (with Team Discount) Modern Robotics REV Robotics

TEAM DISCOUNT

If you order your HUB through the FTC Team Registration page, you save $25 plus you get…

• Free Cable Conversion Kit – normally $25
• Free Color/Distance Sensor – normally $14
• Free Touch Sensor – normally $6
• Free Switch Kit – normally $6

TEAM DISCOUNT

Order direct from REV Robotics and at checkout enter

REVHUB4FTC2017

This saves you $25 on addition Hubs (NO Free Sensors and FTC Cable Conversion Kit)

HYBRID SYSTEMS ARE LEGAL

• Both the REV Robotics Expansion Hub and the

Modern Robotics Core Modules can be used together.

• BUT, if both systems are used together, the

Expansion Hub must be powered by a power port

• n the Modern Robotics Power Distribution Module.

CABLES AND EXTENSION BOARDS

• Cable – 20cm 4/$3
• Cable – 30cm 4/$4
• Cable – 50cm 4/$5
• Extension Board 4/$4

JST PH 4-pin All cables have the same female connector on each end. You will need the Extension Board to connect cables together.

LEVEL SHIFTER

• 5 volt Motor Encoders (Neverest & Tetrix)
• 5 volt Sensors (all I2C Modern Robotics)

The Level Shifter allows 5-volt sensors to work with the Expansion Hub’s 3.3-volt system. The following sensors require a level shifter

$3

LEVEL SHIFTER CABLING

Encoder Wire Sensor Wire

Red mark +5V pin

Suggestion Wires from Expansion Hub

Since the circuit board has the connection information on the opposite side from the pin

• uts, I suggest using a red marker to mark the

+5V side so its easy to connect cables to the Cable Shifter correctly.

MOTOR & ENCODER CONNECTIONS

MOTOR & ENCODER CONNECTION USING LEVEL SHIFTER

SOME SENSORS REQUIRE A SENSOR CABLE (CROSSOVER CABLE)

This Sensor Cable is required to make many some sensors (Modern Robotics I2C) compatible with the Expansion Hub

Modern Robotics I2C Sensor/Device

SENSOR CABLE

Reverses the ground and channel B wires

$1

SENSOR COMPATIBILITY GUIDE

Refer the REV Robotics Expansion Hub User Guide for a complete list

EXPANSION HUB GUIDE

www.revrobotics.com/content/docs/REV-31-1153-GS.pdf

If you are going to use the Expansion Hub, I highly recommend you read this guide

SERVO PORTS

The Good News… The REV Robotics servo ports output a Pulse Width Modulation (PWM) of 500-

• 2500ms. This means your analog servos once again have a default range of

180 degrees, unlike MR’s 135 degrees.

SERVO PORTS

The Good News… The REV Robotics servo ports output a Pulse Width Modulation (PWM) of 500-

• 2500ms. This means your analog servos once again have a default range of

180 degrees, unlike MR’s 135 degrees. The Bad News… These servo ports only output 5 volts instead of 6 volts which is OK in most situations, but that equals about 17% less torque. There is also a 2 amp maximum for each pair of ports possibly limiting the use of several quarter scale servos simultaneously.

SERVO PORTS

The Good News… The REV Robotics servo ports output a Pulse Width Modulation (PWM) of 500-

• 2500ms. This means your analog servos once again have a default range of

180 degrees, unlike MR’s 135 degrees. The Bad News… These servo ports only output 5 volts instead of 6 volts which is OK in most situations, but that equals about 17% less torque. There is also a 2 amp maximum for each pair of ports possibly limiting the use of several quarter scale servos simultaneously. More Good News… REV Robotics has solution to all of the Bad News…

SERVO POWER MODULE

• Restores 6 volt output to

all ports

• 15 amps are shared by

all ports

• You should be able to run

6 analog quarter scale servos simultaneously

• Status lights

SERVO POWER MODULE

12V

• Green – Forward
• Red – Reverse
• Yellow – Neutral
• Yellow Blinking –

Not Connected

• Blue - Power

Status Lights

CONFIGURATION FILE

CONFIGURATION FILE - MOTORS

CONFIGURATION FILE - INTERNAL IMU

The Internal IMU is automatically assigned to I2C Port 0, but you can assign Port 0 to any other I2C sensor.

MY CONCLUSIONS

• Saves a lot of space.
• Much less expensive.
• Only one USB cable.
• I2C individual bus for each
• sensor. Therefore no need to

change sensor addresses.

• Not proven in FTC competitions.
• Level shifters and crossover

cables can make wiring a little more complicated.

• No direct support for Hitechnic

and Lego legacy sensors.

PROS CONS

Would I buy the REV Expansion? Yes!

QUESTIONS?