Tutorial: Level Shifter Board to Connect an SHTW2 to Atmel Xplained Pro
The SHTW2 is designed for a 1.8V supply voltage (1.62..1.98V). To use it with a 5V I2C bus, level shifters are needed. This tutorial describes how to build such a board.
While this is written with Atmel Xplained in mind, the same concept can be used to integrate with any board that has a higher I2C bus voltage than 1.98V (for example most Arduino boards and Raspberry Pi).
Bill of Material
|Voltage Regulator IC||Linear Voltage Regulator IC Positive Fixed 1 Output 1.8V 150mA||Linear Voltage Regulator IC Positive Fixed 1 Output 1.8V 150mA SC-82AB|
|Level Shifters||Level Shifters for I2C communication||MOSFET N-CH 20V .2A EMT3|
Schema for Assembly
Attach to Atmel D20 Board as Extension
Connect the components as described in the schema above or build your own PCB accordingly. Then connect the SCL and SDA pins to the Atmel D20 Xplained Pro platform's pin 11 and 12 for the I2C communication. The SCL_LS and SDA_LS can be used to connect with the Flex PCB of the SHTW2 sensor.
|11||I2C_SDA||Data line for I2C interface. Always implemented, bus type.|
|12||I2C_SCL||Clock line for I2C interface. Always implemented, bus type.|
The VCC and GND of the Flex PCB are connected to the LDO's output 1V8 and GND and the pins 19 and 20 are connected to the LDO's input GND and VCC, respectively.
Copyright (c) 2016, Sensirion AG – www.sensirion.com
All rights reserved.
Definition: The design information in the documents and files made available to you is called "Documentation" and things created from it are called "Product(s)".
Acceptance: By (i) using, copying, modifying, or distributing the Documentation, or (ii) making or having Products made or distributing them, you accept this Agreement and agree to comply with its terms.
Terms and Conditions:
Redistribution, using and copying of the Documentation, in whole or in part, alone or in combination, with or without modification, are permitted provided that the following conditions are met:
* Redistributions of the Documentation must retain the above copyright notice, the definition, the acceptance, this list of conditions and the DISCLAIMER.
* You may make, have made, and distribute Products based in whole or in part on the Documentation. You acknowledge that neither the design nor the Product is tested for your use. You are solely responsible for the application and any use of the Product. You must ascertain the Documentation’s and Product’s specific suitability for your intended purpose and that your use of the Products does not infringe third parties’ rights or other legal and regulatory requirements.
* Products based on the Documentation must reproduce the above copyright notice, the definition, the acceptance, this list of conditions and the DISCLAIMER in the documentation and/or other materials provided with the Products.
* Neither the name of Sensirion AG nor the names of its contributors may be used to endorse or promote products derived from the Documentation without specific prior written permission.
DOCUMENTATION IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE OF THE DOCUMENTATION AND THE PRODUCTS, ARE DISCLAIMED. EXCEPT FOR WILLFUL ACTS AND TO THE MAXIMUM EXTENT PERMITTED BY APPLICABLE LAW, IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES, CLAIMS OF INTELLECTUAL PROPERTY INFRINGEMENT, OR LOSS OF USE, DATA, OR PROFITS, OR BUSINESS INTERRUPTION, OR HARMFUL EFFECTS TO PEOPLE, OBJECTS, ANIMALS, OR PHYSICAL ENTITIES, HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THE DOCUMENTATION AND/OR THE PRODUCTS, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. YOU AGREE TO DEFEND, INDEMNIFY, AND HOLD EACH COPYRIGHT HOLDER AND CONTRIBUTOR HARMLESS FROM ANY CLAIM BROUGHT BY A THIRD PARTY ALLEGING ANY DEFECT IN THE DESIGN, MANUFACTURE, OR OPERATION OF ANY PRODUCT WHICH YOU MAKE, HAVE MADE, OR DISTRIBUTE PURSUANT TO THIS AGREEMENT.