Plug&Trust Click, as its foundation, uses the SE050C, a ready-to-use IoT secure element solution that provides a root of trust at the IC level, and it gives an IoT system state-of-the-art, edge-to-cloud security capability from NXP Semiconductors. It is designed to be used as a part of an IoT system; works as an auxiliary security device attached to a host MCU. It offers enhanced Common Criteria EAL 6+ security certification up to the OS level and supports both RSA and ECC asymmetric cryptographic algorithms with high key length and future proof ECC curves. The latest security measures protect the IC against sophisticated non-invasive and invasive attack scenarios.

The SE050C is a turnkey solution that comes with JavaCard operating system and an applet optimized for IoT security use cases, pre-installed. To support scalability while servicing the broadest range of use cases in IoT applications, the SE050C is available in different pin-to-pin compatible configurations, including versions with support for sensors directly attached to the device, the I2C Controller, or contactless interface.

Plug&Trust Click communicates with MCU using the standard I2C 2-Wire interface, where the host controller represents the Controller and the Click board being the Target. Besides the mandatory connection to the host controller, this Click board™ can optionally be connected to a sensor node or similar element through separate I2C interface pins located on the 1x4 male header labeled as labeled as I2C Master. In this case, the SE050C device is the Controller device, and the sensor node represents the Target.

This Click board™ also offers a choice for the user to select the appropriate I2C communication speed, selected by onboard SMD jumpers labeled as I2C SPEED to a proper position marked as 400Kb and 3.4Mb. Note that all the jumpers must be lined to the same side, or else the Click board™ may become unresponsive. On the other side, the Shutdown pin, labeled as EN and routed to the CS pin of the mikroBUS™ socket, optimizes power consumption and is used for power on/off purposes, while the RST pin has no functionality in I2C Mode. Also, this Click board has an onboard antenna, providing a wireless interface to an external device like a smartphone, connected via a switch labeled as ANTENNA with SE050C allowing the activation of the antenna itself by setting it to the appropriate ON or OFF position.

This Click board™ can be operated only with a 3.3V logic voltage level. The board must perform appropriate logic voltage level conversion before use with MCUs with different logic levels. However, the Click board™ comes equipped with a library containing functions and an example code that can be used, as a reference, for further development.