Added Olimexino-STM32F3 variant

[Stanimir-Petev]

Summary

This PR adds support for the Olimex board Olimexino-STM32F3 including: GPIO, Analog input, Serial UART, I2C, SPI, CAN.
In order to make variant for this board (Olimexino-STM32F3) the variant for Generic STM32F3 (PILL_F303XX) series was taken as a base and then modified to match the hardware configuration.

Link to the board on our website
https://www.olimex.com/Products/Duino/STM32/OLIMEXINO-STM32F3/

PDF of the board schematic
OLIMEXINO-STM32F3_RevB.pdf

Peripheral examples
Olimexino-STM32F3_examples.zip

Notes:

1. I2C example is using MOD-BME280 (https://www.olimex.com/Products/Modules/Sensors/MOD-BME280)
2. SPI example is using MOD-LCD3310 (https://www.olimex.com/Products/Modules/LCD/MOD-LCD3310/)
3. MOD-LCD3310 + SD card example doesn't work with the default SPI library due to the single SPI object.

[fpistm]

Hi @Stanimir-Petev
thanks for this PR.
I know the OLIMEXINO STM32F103:
https://www.olimex.com/Products/Duino/STM32/OLIMEXINO-STM32/open-source-hardware

but I could not find any link on an OLIMEXINO F303, could you share some inputs?

[Stanimir-Petev]

Hi @Stanimir-Petev
thanks for this PR.
I know the OLIMEXINO STM32F103:
https://www.olimex.com/Products/Duino/STM32/OLIMEXINO-STM32/open-source-hardware

but I could not find any link on an OLIMEXINO F303, could you share some inputs?

Hi @fpistm !
Thanks for the fast reply and the tag you made!
I am an Olimex employee. At this stage Olimexino-STM32F3 is just a prototype yet to be released. Hope we get it out soon.

For now I am making only a draft of the PR to see if it will meet the checks requirements and soon I will edit the description. If needed I can post some pictures and/or pdf of the schematic. Also I can provide few examples for the different peripherals, although the one for SD card require a patch in the SPI library (which is probably a subject for another PR). All others work on the prototype I have.

[fpistm]

Will be added later when #1091 will be done

[fpistm]

Hi @Stanimir-Petev
I've included your PR in #1091, it has been reformatted to the new variant definition way.
So I close this one as it is superseded by #1091.
Thanks again for your contribution.

3\. MOD-LCD3310 + SD card example doesn't work with the default SPI library due to the single SPI object.

About this, a first issue is that SDCARD_SS_PIN should be defined to PD2 as it is the real CS for the SD card slot (Software chip select). PB12 is the hardware CS which is not the same. And yes SPI_2 is not instantiate by default. This would be achieve thanks #705 and the support of SPI_INTERFACES_COUNT.
I've successfully tested the embedded SD card slot using the default SD Arduino library using card info example, to test it you can modify the sketch like this:

- const int chipSelect = 4;
+ const int chipSelect = SDCARD_SS_PIN;

-
+  SPI.setMISO(PB14);
+  SPI.setMOSI(PB15);
+  SPI.setSCLK(PB13);
  Serial.print("\nInitializing SD card...");