The SPI-MEMS example, its not great but it does use the SPI

port and can tell you the temperature of the room you are in.

examples/stm32/f4/stm32f4-disco/README

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+README
+------
+
+These examples are designed to demonstrate the use of libopencm3
+with the STM32F4Discovery-DISCO board. This board has a 2.2"
+TFT LCD touchscreen on it, a MEMS gyroscope, and 8MB of SDRAM.
+
+If you move through the examples in this order, the code from
+the previous example will be used in the next example:
+
+0) blink - verify that you can build a program, link it, and
+    download it to the board. Blinks the GREEN LED at about
+    2Hz
+
+1) systick_blink - Clock setup, Systick setup, LED GPIO setup
+    and blinking.
+
+2) usart - Program a USART on the board as a console (requires
+    a digital to serial adapter)
+
+3) usart-irq - Program a USART on the board as a console with
+    an interrupt driven receive routine. This allows you to
+    interrupt execution with ^C as you can on a Linux process.
+
+4) sdram - SDRAM setup, using the usb port as a console, which
+    sets up the SDRAM
+
+5) spi - Serial Peripheral Interface example which talks to
+   the MEMS gyroscope on the DISCO board.
+
+6) lcd-serial - Activates the TFT using the SPI port (serial) and
+    holds a frame buffer in the SDRAM area.
+
+7) lcd - Now uses the new LCD "driver" peripheral to refresh
+    the contents with what is in memory, very fast, write in
+    memory and it appears on screen.
+
+8) dma2d - The 2D graphics accelerator device which displays
+    various animations on the LCD using code from all of the
+    previous examples.