Description

This is a minimalistic template for STM32L1xx project I've made after I've tried many old, outdated and just messy ones and got fed up fixing them.

It requires arm-none-eabi-gcc to compile, and uses either st-flash or stm32flash to program target microcontroller.

It also has a separate 'user application' source directory src, where you should put your own sources to keep things clean. On each build, makefile will search this directory recursively for your C sources, so you don't need to add them manually anywhere.

This template was tested to work on fairly recent (at the time of writing) Arch Linux (amd64, 4.2.5 kernel) with arm-none-eabi-gcc version 5.2.0. I can't guarantee that it will work on different distro/OS, but it's sure the most hassle-free template I've ever had so far :)

Things to customize

• Project name in the BIN variable;
• Set TOOLS_PATH. TOOLS_PREFIX, TOOLS_VERSION and check the rest of the tools definitions according to your compiler;
• Check UART and BAUD, if you're using serial connection and stm32flash;
• STD variable that contains STDPeripheralLibrary modules required by your project;
• Check STARTUP variable and set it according to your device family. You'll find the list of families and devices in the comments of stm32l1xx.h. file, where you also need to uncomment corresponding device family #define.
• Take a look at the stdperiphlib/device_support/gcc/STM32L152VB_FLASH.ld linker script, you might need to change memory sizes, or completely replace it according to your microcontroller.

Warning

I'm not really sure what's going on in the linker script I've mentioned above. By default, it had FLASH and RAM sizes set to 128K and 16K accordingly, even though STM32L152R8T6 (that I'm using in my own project) only has 10K of RAM (according to the datasheet). Different sources specify different figures for some bizarre reason :\

• http://www.st.com/web/en/resource/technical/document/datasheet/CD00277537.pdf, page 11 implies that it has 64K of FLASH and 10K of SRAM;
• http://uk.rs-online.com/web/p/microcontrollers/7957568/ implies that it has 128K of FLASH and 16K of SRAM;
• http://ru.mouser.com/ProductDetail/STMicroelectronics/STM32L152R8T6/?qs=G0rgft3hAxKHKmHne1A%252bnw%3d%3d - 64K FLASH, 16K SRAM.
• My own chip shows up in stm32flash as having 16K of SRAM and 128K of FLASH. Go figure.

Sample program

I've made this template for my own barebone STM32L152R8T6 prototype board. With this template I've included a simple 'Hello world' blink program, that will slowly blink a LED on PA11. You can compile this sample to test if you have your compiler properly installed on your system and properly configured (i.e. path and version) in the makefile.

Useful make targets

• all generates executable and linkable format;
• hex generates ready to upload firmware in Intel HEX format;
• st-flash generates firmware in HEX format and attempts to upload it using st-flash utility;
• stm32flash generates firmware in binary format and attempts to upload it using stm32flash utility using specified serial port and baudrate;
• clean removes object and compiled firmware files according to the makefile;
• hard-clean blindly removes every signle object (*.o) file it will recursively find in project directory. It will also remove firmware files from the project root directory. This target is useful if you forgot to clean your project before changing your makefile (i.e. excluded some module from build, and left its object file). Use with caution.