STM32Lxx things to remember when you start a new project

STM32L1xx
Things to remember when you start a new project

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For start to develop a new project on STM32Lxxx are necessary:

C Compiler, see here

STM32L-Library, see here

Remember to clock the peripherals before use ( system_stm32l1xx.c)
For start to develop a new project is a good idea to use the STM example
KEIL tools

Emulator, for example ST-LINK-v2, see here

Optionally, STM32L-Discovery for quick start
Go here to get this example ready to use

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C Compiler

For choose a C Compiler see here.

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STM32L-Library

Now is available the CUBE, please use it.

The below link are for who started a project before the release of CUBE.

STSW-STM32077 - STM32L1xx standard peripherals library
STSW-STM32002 - Clock configuration tool for STM32L1xx microcontrollers
STSW-STM32081 - STM32F10x and STM32L1xx USB full-speed device library
Extra SW are available here and here

Remember that at power-on all peripherals are OFF so before configure it turn ON the clock on the peripherals that you need to use.
Below there is the Clock-Tree

Remember to select the proper clock source, see CUBE.

For who don't use CUBE the clock configuration is in the file:

system_stm32l1xx.c
Fortunately STM has released an excel file that help us to configure the clock tree.

STSW-STM32002 - Clock configuration tool for STM32L1xx microcontrollers

The excel output is:

system_stm32l1xx.c

that contain the setup for the clocks tree.

For start to develop a new project is a good idea to use the CUBE or STM examples.
First, create a new project directory, for example: MyFirstProject
Second, copy inside the MyFirstProject all the file of STM32L-Library (below is STM32L1xxx_StdPeriph_Lib_V1.1.1)
See below.

The STM examples are in the directory:
C:\...\Project\STM32L1xx_StdPeriph_Examples
See below.

The use of STM Library examples is very easy, it is necessary only to do a copy and paste.
Suppose that you need to test the GPIO-IOToggle example that is in the directory:

C:\...\Project\STM32L1xx_StdPeriph_Examples\GPIO\IOToggle

You must select all the file that are in the IOToggle directory and copy there to the directory:

C:\...\Project\STM32L1xx_StdPeriph_Templates

See below.

Now the way for open the project depend of the tool that you use.
Choose the tools below for continue this tutorial:

KEIL
IAR (coming soon)

KEIL

Now, we suppose that you use KEIL, simply enter in MDK-ARM directory and double click on the file:
Project.uvproj
and KEIL is open automatically.
See below.

Before to compile the project you must:
Configure the I/O, referring your board, in our case we use the STM32L-Discovery and the I/O are configured in this mode:

We decide also to modify the while loop, see below.

Now is necessary configure the MCU that you use and the Debugger (or Emulator) that you use.

Select Teget Option (1) -> Device (2) -> and select your MCU, in our case is STM32L152RB because we use STM32L-Discovery (3)
Next select Debug (4) -> select ST-Link Debugger (this because we use STM32L-Discovery)(5) -> select Settings (6) and in the new window that appear select SWD (7)
Next select Utilities (8) and select again ST-Link Debugger (9)

See below.

Now you are ready to compile and debug your project.

At the end of compilation KEIL show you the code size of the project.
ZI-Data: is the Zero Initialized Data
RO-Data: is the Constants.
Total RAM Size = RW-Data + ZI-Data
Total ROM Size = Code + RO-Data + RW-Data
Some constants (RO-Data) are generated by the compiler/linker and might also be from libraries.

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GPIO example ready to use

If you need this example ready to use go here.

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