Our RedBoards are great. But don't they sometimes seem a little BIG?!

Enter smôl, a new range of boards which are both small in size and small on current draw. It's a smôl world!

You might be wondering why we would make an NFC/RFID tag peripheral board for smôl? The STMicroelectronics ST25DV64KC is a dynamic Near Frequency Communication / Radio Frequency Identification tag IC with 64Kbit (8KByte) of on-board EEPROM memory. It has an I²C interface which the smôl processor board can use to read and write to the EEPROM memory. But the memory can also be read and written to over the RF link while your smôl ecosystem is in deep sleep! This means it is perfect for: contactless data storage and collection; and for configuration.

Let's suppose you have assembled a small data logging system using smôl boards. It spends most of its time in deep sleep, waking up every few hours to take a reading. You want to be able to read the data logged by the system, but you don't want to have to connect a cable to your logger or have to wake it up to get at the data. The NFC/RFID tag peripheral board is the perfect solution. The processor board can write the data into the tag's memory and then go back into deep sleep. You can then read that data with an app on your smartphone at any time!

The NFC/RFID tag peripheral board would also let you configure your smôl logging system. Let's say you want to change the logging interval from 1 hour to 2 hours, but you don't want to have to connect a cable to your logger or have to wake it up to change the interval. Again, the NFC/RFID tag peripheral board is the perfect solution. You can write the new configuration data to the tag using your smartphone. The processor board can then read the new configuration when it next wakes up!

Our Arduino Library provides all of the methods you need to read and write the user memory, control the read and write permissions, alter the area sizes and apply password control. Not only that! We've included extra methods which will let you read and write NDEF (NFC Forum Data Exchange Format) URI, WiFi and Text records which your smart phone can understand! We've tested it with ST's "NFC Tap" App - available from the Apple App Store and Google Play.

smôl is an ecosystem of miniature processor boards, peripheral boards, power boards and accessories. Designed to be both physically small and to have the smallest possible current draw, smôl is the perfect choice for applications like wildlife tracking or discrete long-term monitoring. smôl boards are designed to stack one on top of the other, using 16-way 0.5mm-pitch Flexible Printed Circuits (FPCs) to provide the interconnect from one board to the next. Looking for a really compact solution for your next project? This is it!

We will be adding new smôl boards over the coming months. Don't see the board you need for your application? Reach out to us via the SparkX Forum and tell us which board(s) we should add next!

ST25DV64KC Features:

• Contactless interface
  • Based on ISO/IEC 15693
  • NFC Forum Type 5 tag certified by the NFC Forum
  • Supports all ISO/IEC 15693 modulations, coding, sub-carrier modes and data rates
  • Custom fast read access up to 53 kbit/s
  • Single and multiple blocks read (same for Extended commands)
  • Single and multiple blocks write (up to four) (same for Extended commands)
• Memory
  • 64-Kbit of EEPROM
  • I²C interface accesses bytes
  • RF interface accesses blocks of 4 bytes
  • Write time:
  • From I²C: typical 5 ms for 1 up to 16 bytes
  • From RF: typical 5 ms for 1 block
  • Data retention: 40 years
• Data protection
  • User memory: one to four configurable areas, protectable in read and/or write by three 64-bit passwords in RF and one 64‑bit password in I²C
  • System configuration: protected in write by a 64-bit password in RF and a 64-bit password in I²C

smôl Specifics:

• Interface: I²C
• I²C Addresses:
  • User Memory: 0x53
  • System Memory: 0x57
  • RF Switch Off: 0x51
  • RF Switch On: 0x55

Properties:

• Length: 1.60" (40.6mm)
• Width: 0.42" (10.7mm)
• Height: 0.27" (6.8mm) max.
• Weight: 1.9g (0.07oz)
• PCB thickness: 0.8mm

smôl Dynamic NFC/RFID Tag Documentation:

• Schematic
• Eagle Files
• Dimensions
• Datasheet (ST25DV64KC)
• Application Note (ST25DV64KC)
• GitHub Hardware Repo
• Antenna Datasheet (W3102)
• Arduino Library
• Library Documentation

smôl Documentation:

• smôl Hookup Guide