SparkFun has unveiled a data logging module compatible with their own Thing Plus devices. The SparkFun Thing Plus Dual-Port Logging Shield features an ATtiny841 MCU which allows the user to interface with a microSD card through SPI or USB-C.

According to the company, the Dual-Port Logging Shield was designed for easy data transmission using any standard Arduino SD library. The module can be connected to a computer via USB-C and perform read/write operations with speeds up to 35MBytes/seconds. 

Thing Plus Dual-Port Logging Shield front
(click image to enlarge)

The Dual-Port Logging module uses an ATtiny841 microcontroller to configure the device to SPI mode or USB-C mode. If the shield is powered by a USB-C cable then it will automatically shift to USB mode. If the shield is mounted to a Thing Plus then the device is set to SPI mode. If the shield is connected via USB-C to a computer and mounted to a Thing Plus then the user can configure the ATtiny841 using basic I2C commands.

The logging device also provides access to the serial interface pins (UART) from the ATtiny841 in case an advanced user wants to write their own firmware.

For documentation, SparkFun has prepared a getting started guide, a GitHub repository, an Arduino Library and schematics. 

Serial output example(click image to enlarge)

Specifications listed for the Thing Plus Dual-Port Logging Shield  include:

• Processor System:
  • ATtiny841 microcontroller used to select between SPI or SDIO (“thumb drive”) mode.
• Storage:
  • 1x Push-push microSD socket  (up to 32GB)
• USB:
  • 1x USB-C port
  • USB2241 Ultra Fast USB 2.0 Media Controller
    • Supports cards up to 32GB
    • Supports FAT32, exFAT and NTFS
    • Read and write speed: up to 35 MBytes/second (card-dependent)
• Other Features:
  • Activity LED (for SDIO “thumb drive” mode)
  • Power LED (configurable)
  • The board includes solder pads for an optional 24C04 I2C EEPROM
• Power:
  • Thing Plus/Feather 3.3V
  • USB-C 5V 
  • Sleep current (PWR LED disabled): 300 µA
• Dimensions:
  • 2.30″ x 0.90″ (Thing Plus/Feather footprint)

 Further information

The Thing Plus Dual-Port Logging Shield is available for $29.95 on SparkFun’s website.