Expansion Hub Specifications

The REV Robotics Expansion Hub (REV-31-1153) is a low-cost educational device that can communicate with any computer (commonly the REV Robotics Control Hub or an Android Phone) to provide the interfaces required for building robots and other mechatronics. The Expansion Hub was purpose built to stand up to the rigors of the classroom and competition field. It features a mature firmware designed for basic and advanced use cases with the ability to be field upgraded in the future.

The IO ports of the Expansion Hub are identical in specification to the Control Hub. Within this documentation, many sections may refer to the Control Hub, but the connections are the same for the Expansion Hub.

The REV Robotics Expansion Hub is an approved device for use in the FIRST Tech Challenge and FIRST Global.

Port Label

Qty

Connector

Description

Battery

2

XT30

Connect one 12V NiMh battery, add an Expansion Hub with second port

Motor

4

JST VH, 2-pin

Motor power output

Encoder

4

JST PH, 4-pin

Quadrature encoder input

Servo

6

0.1” Header

Extended range 5V servo output (500-2500ms)

5V Aux Power

2

0.1” Header

Auxiliary device 5V/2A

Analog

4

JST PH, 4-pin

Analog input 0-5.0V measurement range with two channels per connector. 3.3V provided on the connector power pin.

Digital

8

JST PH, 4-pin

Digital Input/Output with two channels per connector

I2C

4

JST PH, 4-pin

Four separate I2C busses, 100kHz/400kHz bus speed

RS485

2

JST PH, 3-pin

Serial communication port to add a Hub (Control or Expansion)

UART

2

JST PH, 3-pin

Debugging only

MINI USB

1

USB Mini-B

Connect directly to the Robot Controller Android device or PC

Specifications

The following tables provide the operating and mechanical specifications for the Expansion Hub.

DO NOT exceed the absolute maximum electrical specifications. Doing so will cause permanent damage to the Expansion Hub and will void the warranty.

Input Power Specifications

Parameter

Min

Typ

Max

Units

Operating voltage range (VINV_{IN})

8

12

15

V

Absolute maximum supply voltage

-

-

15

V

Motor Port Specifications

Parameter

Min

Typ

Max

Units

Continuous output current †

-

-

10

A

Absolute maximum output current ‡

-

-

20

A

Exceeding the continuous current maximum depends on many thermal factors. The outputs will self protect once they approach their thermal limit.

Maximum current is ultimately limited by the in-line battery fuse.

Encoder Port Specifications

Parameter

Min

Typ

Max

Units

Encoder port input voltage

0

-

3.3

V

Encoder port supply voltage

-

-

3.3

V

Encoder port total supply current

-

-

500

mA

See Sensors - Encoders for more information on encoders and using the encoder ports. For using non-REV motor encoders see Using 3rd Party Sensors - Encoders for more details.

Digital Port Specifications

Parameter

Min

Typ

Max

Units

Digital port input voltage

0

-

3.3

V

Digital port supply voltage

-

-

3.3

V

Digital port total supply current

-

-

1

A

See Sensors - Digital for more information on using the digital ports. See Using 5V Sensors for information on using 5V logic level devices with the digital ports.

Analog Port Specifications

Parameter

Min

Typ

Max

Units

Analog port input voltage range †

0

-

5

V

Analog port supply voltage

-

-

3.3

V

Analog port total supply current

-

-

500

mA

The analog input will accept up to 5V. When using 5V analog sensors, a custom wiring harness is needed to provide 5V of power for the sensor as the power pin provides 3.3V.

See Sensors - Analog for more information on using the analog ports.

I2C Port Specifications

Parameter

Min

Typ

Max

Units

I2C port input voltage range

0

-

3.3

V

I2C port supply voltage

-

-

3.3

V

I2C port total supply current

-

-

500

mA

Bus speed

-

100/400

-

kHz

See Sensors - I2C for more information on using the I2C ports. See Using 5V Sensors for information on using 5V logic level devices with the I2C ports.

Servo Port Specifications

Parameter

Min

Typ

Max

Units

Servo output signal voltage

0

-

5

V

Servo port supply voltage

-

5

-

V

Servo port pair total supply current †

-

-

2

A

Absolute maximum total supply current ‡

-

-

5

A

Servo port output pulse range

500

-

2500

μs

Total supply is shared across pairs of ports (0-1, 2-3, 4-5)

The 5A total supply current for all servo ports and +5V power ports is shared.

+5V Power Port Specifications

Parameter

Min

Typ

Max

Units

+5V power port output voltage

-

5

-

V

+5V power port pair total supply current †

-

-

2

A

Absolute maximum total supply current ‡

-

-

5

A

Total supply current is shared across both ports

The 5A total supply current for all servo ports and +5V power ports is shared.

Mechanical Specifications

Parameter

Min

Typ

Max

Units

Body length

-

103

-

mm

Body width

-

143

-

mm

Body height

-

29.5

-

mm

Weight

-

209

-

g

Mounting hole pitch

-

16

-

mm