Digital logging of environmental data requires a device that can gather data from sensors and store it. Arduino microcontrollers are well suited for this task when a few components are added
Enterprising technologists have built custom printed circuit boards (Riffle, Mayfly logger) that combine an Arduino compatible chip with an RTC and a slot for a microSD card. These elegant solutions sell for many times the price of a basic Arduino (e.g., $60.00 compared to $6.00).
Adafruit Feather M0 Basic Proto – ATSAMD21 Cortex M0: At the Feather M0’s heart is an ATSAMD21G18 ARM Cortex M0 processor, clocked at 48 MHz and at 3.3V logic, the same one used in the new Arduino Zero. This chip has a whopping 256K of FLASH (8x more than the Atmega328 or 32u4) and 32K of RAM (16x as much)! This chip comes with built in USB so it has USB-to-Serial program & debug capability built in with no need for an FTDI-like chip. Read more.