Battery Management System (BMS) - Firmware

This is the firmware dev section of the BMS project, as the hardware section states, the brain of the BMS is based on a STM32F407VGTx microcontroller unit.

It's mainly based on STM32Cube HAL (Hardware Abstraction Layer) and the CMSIS (Cortex Microcontroller Software Interface Standard).

To clone this repo run:

git clone --recursive -j8 https://github.com/moyamartin/bms_firmware.git

Folder Structure

• Core: Contains the firmware main source and header files related to the project's firmware

• Test: Contains the unit tests related to different algorithms of the project, unit tests are NOT related to device drivers and so on. We would need to work on a hardware in the loop testing workbench for that.

• Drivers: Contains the STM32Cube HAL, CMSIS software package and device drivers for the different peripherals of the main board

Features

The firmware has to be able to accomplish the following goals:

• Estimate the state of charge of the battery using a Kalman Filter and an electrical model of a 18650PF (Under test).
• Device drivers for the peripherals of the BMS in order to get the following information:
  • Discharge/charge current
  • Cell voltage
• Unbalanced cell detector
• Finite-state machine for handling charge/discharge phases
• Communicate the current status of the battery pack via CAN bus or RS232 protocol
• Handle failure interruptions and trigger the load switch for protection
• Handle the battery charger indicators (WIP)

Requirements

Software

Before building and loading the firmware into the board, first you'll need to install the GNU ARM embedded toolchain and OpenOCD (On-Chip Debugger) or you can install the STM32CubeIDE and import it as this proyect is compatible with that development environment.

Hardware

You will need a STLink/V2 in-circuit debugger/programmer in order to loadand debug the firmware on the board.

NOTE: if you have a STM32F4discovery board or another known board that has a STLink programmer with accessible pins you won't need to acquire an stand-alone programmer in order to load the firmware to the board, you only need to connect the SWDIO pins.

Build and Run

Linux

Open a terminal and run the following steps

1 - Go to the cloned repo's folder

cd root_path/bms_unr 

2 - Run make to build the firmware . This will create a build folder containing the binaries of the firmware (.bin, .hex and .elf).

NOTE: to build the firmware without debug symbols modify the Makefile and set the DEBUG variable to 0. (WIP, run make debug or make prod to avoid changing this variable manually)

2- To load the firmware to the microcontroller run the following command

openocd -d0 -f board/stm32f4discovery.cfg -c "init;targets;halt;flash write_image erase bms_firmware.hex;shutdown"

3 - To debug the firmware you first have to run an openocd server on a terminal running (Make sure that you are building the project with debug symbols, otherwise you won't be able to see C code in GDB)

openocd -f board/stm32f4discovery.cfg

and on a separate terminal run

arm-none-eabi-gdb -f root_path/bms_firmare/build/bms_firmare.elf -x init.gdb

Windows

Testing

We are running some local test for specific algorithms using Cpputest. To run them first build and configure the framework running:

cd path_to_repo/Test/cpputest/cpputest_build && autoreconf .. -i && ../configure && make && mkdir ../lib && cp ./lib/* ../lib/

And them, to execute the tests run:

cd Test && make -B gcov

This will make a test coverage html file saying which tests passed or failed