Welcome to BMS’s documentation!

Introduction

The DEV1-BMS is the Battery Management System for the RIT-EVT Dirt Electric Vehicle (DEV1). The system is based around the BQ76952 TI battery monitor and protector chip. The firmware for the DEV1-BMS is written for the STM32f334 microcontroller that is designed into the DEV1-BMS.

The DEV1-BMS will have the following responsibilities.

1. Run safety checks during DEV1 operation

2. Facilitate battery charging

3. Act as an interface to the on-board BQ76952

4. Expose the system over the DEV1 CAN network

For a more detailed description of the requirements, refer to the DEV1-BMS Software Requirements Specification

The DEV1-BMS project is in its rampup phase. Currently documentation is being generated for the project including requirements and implementation design.

The DEV1-BMS project is currently in the hardware bringup phase. Software testing has taken place with a BQ76952 EVM, external EEPROM, and external CAN transciever. Preliminary testing has taken place on EVT produced hardware, but additional testing and features are needed before the system is ready for use on the bike. A detailed description of the current state of the BMS software is linked below.

Contents:

• API
  • DEV
• Software Requirements Specification for DEV1 Battery Management System
  • Introduction
  • Overall Description
  • Specific Requirements
  • Other Nonfunctional Requirements
  • Appendix
• State of the BMS Software
  • Introduction
  • High Level Features
  • System State Machine
  • Code Breakdown
  • Current State of Features
• BQ76952
  • BQ76952 Settings Transfer
  • BQ Settings Convert and Transfer Utilities

State Transition Diagram

For a look at each stage of the BMS firmware in action. The state diagram below can be used.

The functionality of the BMS can be broken down into 4 major components. The “Startup” logic which involves getting the settings for the BQ chip and transferring those setting from a seperate host via CANopen, to EEPROM, and finally to the BQ chip itself. The “Ready” state which is where the BMS spends the bulk of its time, checking on the health of the BMS system, and waiting for the system to either charge or discharge. The “Charging” state where the BMS mediates charging the batteries. Finally the “Power Delivery” state where the BMS is handling delivering power. The logic for flowing between the different states is detailed in the diagram above.

EVT-core

EVT-core is the RIT-EVT produced library for interfacing with the STM32f302r8 that will be on the DEV1-BMS. For more information on that library, visit RTD for EVT-core

Indices and tables

• Index

• Module Index

• Search Page