Setting up the rpi

The following steps yields a rpi that can interface with the firmware on the Nucleo F401RE via SPI. The rpi and the STM32F401 must be connected as explained here.

  • Download and install raspbian
  • Update the system
  • Run raspi-config and enable SPI
  • Resize SPI buffer (by default it’s too small). Append the following to the line in /boot/cmdline.txt:
    spidev.bufsiz=8192
  • Install wiringPi

Command line interface

To install a command line interface the following further steps are required:

  • Download the Otterly-rpiCLI
  • Unzip, enter directory, and type ‘make’

The CLI takes the following options:

  • ICG-period
  • SH-period
  • fM-frequency
  • output file

Graphical user interface

To install a graphical user interface the following further steps are required:

  • Install libgtk-3-dev
  • Install gnuplot
  • Download the Otterly Raman GUI
  • Unzip, enter directory, and type ‘make’.

The resulting executable should look something like this. Not all features have been implemented yet, but you can set the integration time and collect data (record).

otter-gui-no-scope

The Otter Raman GUI. The rpi was accessed remotely through VNC.

The data is saved in the “default_datafile.dat” and plotted with gnuplot in the file “default4_plot.svg”. Both files are overwritten each time Record is pressed.

For a more feature-rich version of the GUI have a look at the work of Jens-Ulrich Fröhlich’s blog Leaves of science. He uses Octave for data-manipulation.


Connecting to the rpi

In case you don’t have a dedicated screen, keyboard and mouse for your rpi, an easy way to connect to the rpi is to set it up as an access-point: