Are you looking for a powerful and flexible solution that can enhance the performance and security of your devices? Then you might want to check out the ST25DV-DISCOVERY, a state-of-the-art development board that allows you to leverage the capabilities of the ST25DV dynamic NFC/RFID tag IC.

In this blog post, we will dive into the details of the ST25DV-DISCOVERY and showcase some of its most impressive features and use cases. With a technical overview, practical examples and code snippets, you will get a thorough understanding of how this board can unlock new possibilities for your designs.

Technical Overview

The ST25DV-DISCOVERY is built around the ST25DV04K dynamic NFC/RFID tag that supports ISO/IEC 15693, ISO/IEC 14443A/B, NFC Forum Type 4 Tag and NFC Forum Type 5 Tag technologies. Its main features include:

Up to 4-Kbit EEPROM memory with flexible organization and access control

Fast transfer modes up to 1.6 Mbps for ISO/IEC 15693 and up to 424 kbps for ISO/IEC 14443A/B

Energy harvesting and power-saving modes for optimized power management

Multiple password-protected security levels and anti-cloning mechanisms for increased protection against attacks

The ST25DV-DISCOVERY board also integrates an STM32L476JG MCU with an ARM Cortex-M4 core that drives the ST25DV tag and provides additional interfaces such as USB, UART, SPI, I2C, CAN and ADC. The board is powered via USB or a CR2032 coin cell battery and comes with a software development kit (SDK) that supports programming in C, Python and Java.

Practical Examples

To illustrate the versatility and flexibility of the ST25DV-DISCOVERY, let's explore some examples of its use cases and how to implement them using the SDK:

1. NFC File Sharing

With the ST25DV-DISCOVERY, you can easily exchange files and data between devices by leveraging the NFC capabilities of the ST25DV tag. Here's how you can implement a basic file transfer module in Python:

import nfcimport ndefdef on_connect(tag): file_data = open("sample.txt", "r").read() file_ndef = ndef.TextRecord(file_data) tag.ndef.message = ndef.Message(file_ndef) print("File sent to tag.")with nfc.ContactlessFrontend('usb') as clf: print("Waiting for tag...") clf.connect(rdwr={'on-connect': on_connect})

In this example, we use the nfcpy library to detect and communicate with the ST25DV tag via USB. Once the tag is detected, we read the contents of a sample file and convert it into an NDEF (NFC Data Exchange Format) record that can be stored in the tag's memory. Finally, we set the message of the tag's NDEF object to the file record and print a confirmation message.

2. Sensor Data Acquisition

The ST25DV-DISCOVERY can also be used to acquire and store sensor data from external devices, such as temperature sensors, accelerometers or light sensors. Here's how you can read and store the data from a TMP102 temperature sensor via I2C:

include "mbed.h"include "ST25DV.h"include "TMP102.h"ST25DV mem(D14, D15, D4, D5);I2C i2c(D4, D5);TMP102 temp_sensor(i2c);int main() { mem.init(); temp_sensor.init(); while(1) { float temp = temp_sensor.readTemp(); mem.writeData(0x00, (uint8_t) &temp, sizeof(temp)); printf("Temperature: %.2f C\n", temp); wait(1.0); }}

In this example, we use the mbed library to program the STM32L476JG MCU and interface it with the ST25DV and TMP102 components via I2C. We first initialize the memory and sensor objects and then enter an infinite loop that reads the temperature value from the sensor, stores it in the ST25DV tag's memory and prints it to the console. We also add a delay of 1 second between measurements to avoid flooding the tag's memory.

Conclusion

The ST25DV-DISCOVERY is a powerful and versatile development board that can simplify and streamline many aspects of your device designs. With its advanced NFC/RFID capabilities, high-speed data transfer modes, energy harvesting and power-saving modes, and robust security features, this board opens up new opportunities for applications such as data logging, asset tracking, smart packaging, wireless charging and more.

If you are interested in learning more about the ST25DV-DISCOVERY and other ST products and solutions, please visit the official ST website for resources, tutorials, forums and more.