 And now we are going to look at the supporting ecosystem for the SD-25DV. The SD-25DV ecosystems have many components that aid your NFC product development. We supply complete datasheets, online antenna design software, schematics, build material lists, and Gerber files. We also provide Android and iPhone apps so that you can use the phone for testing. If you plan to use SEM32, we have example codes to help you. Also, our software drivers are written in C so that you can port it to any other microcontrollers. When it comes to evaluation boards, you can choose either the Discovery Kit or the X-Nuclear Shields. The Discovery Kit comes with turnkey firmware which makes it ideal for trying NFC and feature set of SD-25DV. The X-Nuclear Ecosystem is great if you plan to start prototyping your design and add other features such as sensor in form of stackable shields boards. If you look at the SD-25DV Discovery Board, you will notice that a version of full-cabit device is used. The board comes with LCD and touchscreen. Beside the LCD touchscreen, there are two USB ports where you can connect to power up the board. Optional header for updating Wi-Fi firmware is available. All the LEDs including SD-Link activity, user, and energy harvesting is also a small joystick. Be aware that when you want to use the board for upgrading the firmware or debugging, you should use the mini USB port because this port is connected to the SCM32F103 debugging processors on the board. The back of the board shows the SCM32F415 soldering patterns for BOE and Wi-Fi modules. The extension connector will accept different antenna boards so that you can test performance range from Class 1 with a round credit card size. To Class 6, it's around 25 x 30 mm. If you like to install the BOE and Wi-Fi modules, these links will give you more information regarding the modules. The XNUCLEO NFC04A1 is the official shield. Bored for the SD25DV, it features a 54 mm diameter and 8 turns single layer antenna. Other features include three LEDs, energy harvesting output pin, GPO, and low power down. It is compatible with all SCM32 nuclear boards. Once you have acquired the NFC04A1 board, please go to sc.com and download the firmware. It comes with sample codes to demonstrate enabling of energy harvesting features, activate GPO, activate LPD or low power mode, setting I2C protection and the use of SD25DV mailbox or fast transfer mode and writing UI and Dev messages. If you use SCM32 for your microcontroller, the existing SD25DV driver is cube compliant. Also, the SC25DV discovery firmware is derived from the SCM32 cube. Here's a snapshot of the NFC04 software pack, showing all the components. Notice that the example for F4 and L0 are shown. Finally, we like to cover a little bit on NFC-TEC antenna design for the SC25DV. We're going to quickly go to theory of antenna design, PCB antenna design, metal considerations, and measurement methodology. At the circuit level, we can see the equivalence between the dynamic tech IC and the antenna itself. The IC has the chip resistance and capacitance, and the antenna consists of loop resistance, parasitic capacitance, and the resultant inductance. The recent frequency of the chip and the antenna combination is determined via the formula as seen here. You can use this relationship to determine needed parameters such as target antenna inductance and resonant frequency. In this diagram, you can see that tag number 2 is located at the same resonant frequency as the reader, which will give the best read range. Tag number 1 and number 3 are out of resonant and need to be tuned up and down respectively. Keep this in mind when you use both readers and dynamic techs in a complete design so that you can optimize the read range. In this diagram, you can see that tag number 2 is located at the same resonant frequency as the reader, which will give the best read range. Tag number 1 and tag number 3 are out of resonant and need to be tuned up and down respectively. Design antenna is a complex process. While all antennas of different shapes can be represented by equations, it is much better if a software will manage all the computation for you. When it comes to HF antenna design, ST offers an online tool called the design suite. The ST design suite will let you design a single layer antenna on standard PCB with half ounce copper at 35 micron thick. You will need to enter the dimension of the antenna, the trace width and trace separation. The output will be the inductance of the antenna. Knowing that the chip capacitance of the ST25 DV is around 28.5 picofarad, you can use the following equation to look for the ideal antenna inductance at 13.56 MHz, which is around 4.83 MHz. Use the ST design suite to design a class 1 antenna with a dimension of 45 by 75 mm. So in general, the main value to go after is the inductance of the antenna. And this inductance can be changed via the antenna dimension, number of turns, conductor width and conductor's gaps. All the parameters such as conductor thickness and number of segments can also change the inductance. Now, if you look at the equation again, you can actually add capacitance to the chip's capacitance so that you can tune just in case if your inductance of the antenna comes out differently. So it may be wise to design an antenna with slightly less inductance and include a footprint for a small capacitor in parallel with the AC0 and AC1 input of the ST25 DV. There are two ways to measure the resonant frequency. Network analyzer with loop probe, this is by far the easiest way, simply set the network analyzer for S11 measurement. The second method requires an oscilloscope, loop antenna and a signal generator. Thank you and this concludes our segment on ST25 DV Dynamic Tags.