SEK-SensorBridge Technical GuideConnecting Bridge with 2 Sensor PortsHighlights•••

I2C Bus with speeds up to 1MHz
1.2V-5.5V Selectable supply in voltage steps
Connect up to 2 Sensor Evaluation Kits••

Micro USB Virtual COM Port
RS485 Serial Connector

The SEK-SensorBridge (referred to as SensorBridge) is the universal tool of Sensirion when it comes toevaluation. Sensirion offers a huge variety of sensors and SensorBridge is used to connect the different
Evaluation Kits and the different evaluation tools and drivers Sensirion offers.

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1 / 10Contents
1

Quick Start Guide................................................................................................................................................................................ 3

2SensorBridge Hardware Specifications ...................................................................................................................................... 4
2.1 RJ45 Connection ....................................................................................................................................................................... 4
2.2 RS485 Connection.................................................................................................................................................................... 5

3

Software Compatibility ..................................................................................................................................................................... 6
3.1 ControlCenter compatibility ................................................................................................................................................ 6
3.2 Python compatibility ............................................................................................................................................................... 6

4Evaluation Kit Compatibility list .................................................................................................................................................... 7

5

Revision History ................................................................................................................................................................................... 9www.sensirion.com / D1

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Quick Start Guide

To connect a Sensor Evaluation Kit (SEK) via SensorBridge to your computer follow the next steps:1.
2.
3.
4.

Use the adapter cable supplied with your SEK and connect it to the female connector on the evaluation
boardConnect the RJ45 connector of the adapter cable to either of the two RJ45 ports on the SensorBridge
Use the supplied Micro USB to USB cable to power and connect the SensorBridge to your computer
Launch ControlCenter

Figure 1. Typical connection diagram to a computer with a SensorBridge and Sensor Evaluation Kit.
Find about the evalution kits on Sensirion Website: Sensor evaluation (sensirion.com)
Find about the compatibility list of SensorBridge in the Evaluation Kit Compatibility list

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3 / 102SensorBridge Hardware Specifications

Figure 2: SensorBridge with a usb cable

The hardware specifications of the SensorBridge are the following:• Two independent channels are provided through two RJ45 ports, each offering:o I2C Bus with speeds up to 1MHzo 1.2V-5.5V Selectable supply in voltage stepso Analog In Pin (0V – 5V)• Micro USB Virtual COM Port
• RS485 Serial Connector
Packaging includes:• SEK-Sensorbridge• Micro USB to USB-A cable• Flyer with information
Total weight with packaging and USB cable: 140g

2.1

RJ45 Connection

Each one of the two RJ45 connectors can be used to connect one Sensor Evaluation Kit via the supplied cablewith the specific sensor evaluation kit. The Pinout and the Pin association with the connector are shown in thefollowing table and diagram:
Pin
1

GND

2

SCK

3

SCL

4

MISO

5

VDD

6MOSI

7SDA

8Analog In

Table 1. Pinout and Pin association Diagram for the RJ45 Connector

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4 / 10A standard MicroUSB connector is used to connect the SensorBridge with the computer. This is used both forthe evaluation through ControlCenter and to access the sensor through the Python Library for Sensorbridge.
Please make sure to use a cable suitable for data transfer through USB and not a cable suitable only for powertransfer.

2.2

RS485 Connection

SensorBridge supports serial connections through an RS485 connector.
The physical connector is a 4Pin 1.25mm pitch connector from JST (type GHR-04V-S). The pinout and thecharacteristics of the connector are shown in the following figures:

Pin1

RS485 A+

2

RS485 B-

3GND

45V

Table 2. Pinout and Pin association Diagram for the RS485 Connector
Please note that for the RS485 connection to work Sensorbridge must not be connected through the Micro
USB connector.

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Software Compatibility

The users have three ways to connect to a sensor via the SensorBridge:
1. For plug and play evaluation of the sensor the SensorBridge is compatible with ControlCenter
2. For prototyping with Python and UART the users can connect via either:a. The microUSB and the virtual COM port orb. The RS485 connector as explained in earlier sections

3.1

ControlCenter compatibility

SensorBridge is compatible with Sensirion’s ControlCenter. Please visit Sensirion’s website to download thelatest version of ControlCenter.
To connect a Sensor Evaluation Kit (SEK) via SensorBridge to your computer follow the next steps:
1.
2.
3.
4.

3.2

Use the adapter cable supplied with your SEK and connect it to the female connector on the evaluation
board
Connect the RJ45 connector of the adapter cable to either of the two RJ45 ports on the SensorBridge
Use the supplied Micro USB to USB cable to power and connect the SensorBridge to your computer
Launch ControlCenter

Python compatibility

For users who want to prototype using their Sensor Evaluation Kits and Sensorbridge, Sensirion provides aPython Library to connect through the SensorBridge to the Sensor.
The library implements the Sensirion SHDLC protocol based on the UART protocol.
This library is compatible both through the virtual COM port connection with the MicroUSB connector andthrough the serial RS485 connector.
You can find more information about the library in the relevant Github repository.
Currently only Python is supported for SensorBridge support.

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3.3

How many sensors can I connect at the same time?

Each SensorBridge can support up to two independent i2c buses through the two RJ45 ports
There is no limit as to how many SensorBridges can be connected at the same computer. The only limitationis that each SensorBridge can have at most 3kHz frequency in the measurements.

3.4 How many SensorBridges can I connect at the same time?
There is no limit as to how many SensorBridges can be connected at the same computer. The only limitationis that each SensorBridge can have at most 3kHz frequency in the measurements.

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Evaluation Kit

Material Number

SEK-SHT40
SEK-SHT40 Filter

3.000.462

SEK-SHT41
SEK-SHT40ISEK-SHT41I

3.000.637

SEK-SHT40A

3.000.706

SEK-SHT41A
SEK-SHT45

3.000.707

SEK-SHTC33.000.110

SEK-SHTW2
SEK-SHT31

3.000.109

SEK-SHT35
SEK-SCC30-DB
SEK-STS40

3.000.113

SEK-STC31
SEK-SCD4x
SEK-SCD30

3.000.472

SEK-SEN5x3.000.670

SEK-SDP8xx
SEK-SDP31

3.000.764

SEK-SFM4300-20-P
SEK-SFM4200
SEK-SFM4100

3.000.399

SEK-SFM3200
SEK-SFM3119
SEK-SFM3019

3.000.324

SEK-SFM3013
SEK-SFM3003

3.000.525

SEK-SFM3000

3.000.323

3.000.892
3.000.639
3.000.640

3.000.730

3.000.112
3.000.171
3.000.703
3.000.455
3.000.055

3.000.763
3.000.326
3.000.325
3.000.613
3.000.420
3.000.524

Table 3. Evaluation Kit Compatibility List.

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Date
Date (Month Year)

VersionPages

Changes

1all

Initial version

Date (Month Year)www.sensirion.com / D1

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9 / 10Important Notices
Warning, Personal Injury
Do not use this product as safety or emergency stop devices or in any other application where failure of the product could
result in personal injury. Do not use this product for applications other than its intended and authorized use. Before installing,handling, using or servicing this product, please consult the data sheet and application notes. Failure to comply with these
instructions could result in death or serious injury.
If the Buyer shall purchase or use SENSIRION products for any unintended or unauthorized application, Buyer shall defend,
indemnify and hold harmless SENSIRION and its officers, employees, subsidiaries, affiliates and distributors against all claims, costs,damages and expenses, and reasonable attorney fees arising out of, directly or indirectly, any claim of personal injury or deathassociated with such unintended or unauthorized use, even if SENSIRION shall be allegedly negligent with respect to the designor the manufacture of the product.
ESD Precautions
The inherent design of this component causes it to be sensitive to electrostatic discharge (ESD). To prevent ESD-induced damage
and/or degradation, take customary and statutory ESD precautions when handling this product. See application note “ESD, Latchupand EMC” for more information.
Warranty
SENSIRION warrants solely to the original purchaser of this product for a period of 12 months (one year) from the date of delivery
that this product shall be of the quality, material and workmanship defined in SENSIRION’s published specifications of the product.
Within such period, if proven to be defective, SENSIRION shall repair and/or replace this product, in SENSIRION’s discretion, freeof charge to the Buyer, provided that:•
notice in writing describing the defects shall be given to SENSIRION within fourteen (14) days after their appearance;•such defects shall be found, to SENSIRION’s reasonable satisfaction, to have arisen from SENSIRION’s faulty design, material,or workmanship;•the defective product shall be returned to SENSIRION’s factory at the Buyer’s expense; and•the warranty period for any repaired or replaced product shall be limited to the unexpired portion of the original period.
This warranty does not apply to any equipment which has not been installed and used within the specifications recommended by
SENSIRION for the intended and proper use of the equipment. EXCEPT FOR THE WARRANTIES EXPRESSLY SET FORTH HEREIN,SENSIRION MAKES NO WARRANTIES, EITHER EXPRESS OR IMPLIED, WITH RESPECT TO THE PRODUCT. ANY AND ALL
WARRANTIES, INCLUDING WITHOUT LIMITATION, WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULARPURPOSE, ARE EXPRESSLY EXCLUDED AND DECLINED.
SENSIRION is only liable for defects of this product arising under the conditions of operation provided for in the data sheet andproper use of the goods. SENSIRION explicitly disclaims all warranties, express or implied, for any period during which the goods
are operated or stored not in accordance with the technical specifications.
SENSIRION does not assume any liability arising out of any application or use of any product or circuit and specifically disclaims
any and all liability, including without limitation consequential or incidental damages. All operating parameters, including without
limitation recommended parameters, must be validated for each customer’s applications by customer’s technical experts.
Recommended parameters can and do vary in different applications.
SENSIRION reserves the right, without further notice, (i) to change the product specifications and/or the information in thisdocument and (ii) to improve reliability, functions and design of this product.

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Sensirion AG
Laubisruetistr. 50CH-8712 Staefa ZH
Switzerland

Sensirion Inc., USA
phone: +1 312 690 5858
info-us@sensirion.com
www.sensirion.com

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info-kr@sensirion.com
www.sensirion.com/kr

phone: +41 44 306 40 00
fax:+41 44 306 40 30
info@sensirion.com
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phone: +81 45 270 4506
info-jp@sensirion.com
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Sensirion China Co. Ltd.
phone: +86 755 8252 1501
info-cn@sensirion.com
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phone: +886 2 2218-6779
info@sensirion.com
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To find your local representative, please visit
www.sensirion.com/distributors

Copyright © 2022, by SENSIRION. CMOSens® is a trademark of Sensirion. All rights reserved
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