• Logging local temperature changes over time
  • Log interval configurable anywhere from one second to one week)
• Logging multiple temperature locations (up to 127 on a 3 wire cable)
• Logging GPS data from nearly any serial GPS module
• A serial source stream such as GPS emulation

Features:

• SD card slot for SD or uSD (with adapter) flash card, push-in/push-out type.
• Battery backed Real Time Clock (DS1392) for adding timestamps to logs.
  • RTC interrupt allows unit to sleep (conserve energy) and then wake up at a predetermined time/day.
• Temperature sensor (DS18B20) for local temperature measurements
• Polarized header allows for easy addition of up to 127 external sensors on the Dallas 1-wire bus.
• Voltage regulation (accepts 3.5 to 16v input) onboard. Stuffing option regulator allows wider voltage range with improved efficiency and extra power for external components.
• 3.3 to 5v tolerant serial communication. Defaults to 9600 baud (higher rates available).
• Arduino-like architecture, using the Atmel ATmega328 running at 3.3v/16MHz.
• FTDI Basic Breakout (5V) style serial header connector for upgrading or customizing firmware.
• LEDs to indicate power and SD card access
• Two more user programmable LEDS  (used to indicate SD error, and RTC pulse on provided demo app).
• Full source code provided; customize to fit your need or use it as is.
• Six spare microcontroller pins broken out for digital I/O or analog inputs.
• Spare I/O, TTL serial, and power brought out to 0.100” spaced headers for prototyping, probing, or customization.
• Five more 0.100” spaced unconnected holes available for prototype additions such as a GPS module (see below).
• Power on/off switch to select external or USB (FTDI) power source.
• JST connector to supply power from battery, wall-wart, etc.
• Reset button.

• Open source (see link below).
• Comes loaded for stand-alone temperature logging or as a serial logger/slave from any device with 3.3-5v TTL RS-232 output.
• Easily configurable code to set logging frequency, file name, precision, etc.
• Write/append files with or without time stamp. File access date/time updates automatically.
• Simple serial interactive menu can be used directly/manually, or as a slave to your device.

    Serial commands currently available:   
        h/?: Lists available commands
        f:     set File Name
        a:    append file with string
        r:     read file(arg is last X KBytes, def is 0/all)
        d:    Directory
        m:   manual temp log add
        i:     init SD Card
        t:     read rtc time
        u:    update rtc time
        c:    CD/WP bits status
            New commands added regularly, also upon request