OpenLog Hookup Guide

Contributors: Nate, Toni_K
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The OpenLog has two primary pieces of software on board: the bootloader and the firmware.

Arduino Bootloader

Note: If you are using an OpenLog that was purchased prior to March 2012, the onboard bootloader is compatible with the "Arduino Pro or Pro Mini 5V/16MHz w/ ATmega328" setting in the Arduino IDE.

As mentioned previously, the OpenLog has the Optiboot serial bootloader on board. You can treat the OpenLog just like an Arduino Uno when uploading example code or new firmware to the board.

If you end up bricking your OpenLog and need to reinstall the bootloader, you will also want to upload Optiboot onto the board. Please check out our tutorial on installing an Arduino Bootloader for more information.

Compiling and Loading Firmware onto the OpenLog

Note: If this is your first time using Arduino, please review our tutorial on installing the Arduino IDE. If you have not previously installed an Arduino library, please check out our installation guide to manually install the libraries.

If for any reason you need to update or reinstall the firmware on your OpenLog, the following process will get your board up and running.

First, please download the Arduino IDE v1.6.5. Other versions of the IDE may work to compile the OpenLog firmware, but we have verified this as a known good version.

Next, download the OpenLog firmware and required libraries bundle.

Once you have the libraries and firmware downloaded, install the libraries into Arduino. If you are unsure how to manually install the libraries in the IDE, please check out our tutorial: Installing an Arduino Library: Manually Installing a Library.

Note: We are using modified versions of the SdFat and SerialPort libraries in order to arbitrarily declare how big the TX and RX buffers should be. The OpenLog requires the TX buffer to be very small (0) and the RX buffer needs to be as large as possible. Using these two modified libraries together allows increased performance of the OpenLog.

Next, to take advantage of the modified libraries, modify the SerialPort.h file found in \Arduino\Libraries\SerialPort directory. Change BUFFERED_TX to 0 and ENABLE_RX_ERROR_CHECKING to 0. Save the file, and open up the Arduino IDE.

If you haven't yet, connect your OpenLog to the computer via an FTDI board. Please double check the example circuit if you are not sure how to do this properly.

Open the OpenLog sketch you would like to upload under Tools>Board menu, select the "Arduino/Genuino Uno", and select the proper COM port for your FTDI board under Tools>Port.

Upload the code.

That's it! Your OpenLog is now programmed with new firmware. You can now open up a serial monitor and interact with the OpenLog. On power up, you will see either 12> or 12<. 1 indicates the serial connection is established, 2 indicates the SD card has successfully initialized, < indicates OpenLog is ready to log any received serial data and > indicates OpenLog is ready to receive commands.

OpenLog Firmware Sketches

There are three included sketches you can use on the OpenLog, depending on your particular application.

  • OpenLog - This firmware ships by default on the OpenLog. Sending the ? command will show the firmware version loaded onto a unit.
  • OpenLog_Light - This version of the sketch removes the menu and command mode, allowing the receive buffer to be increased. This is a good option for high-speed logging.
  • OpenLog_Minimal - The baud rate must be set in code and uploaded. This sketch is recommended for experienced users but is also the best option for the highest speed logging.