CAN Library

• CAN Library
• 1 Overview
• 2 Usage
  • 2.1 Git Submodule
  • 2.2 Update Library
• 3 CAN Message Documentation
  • 3.1 BMS
    • 3.1.1 State
    • 3.1.2 Cell Data
    • 3.1.3 Accumulator Voltage
    • 3.1.4 Accumulator Temperature
  • 3.2 APPS
    • 3.2.1 Normalized Brake
    • 3.2.2 RMS Param Msg
    • 3.2.3 RMS Command Msg
    • 3.2.4 BSPD
    • 3.2.5 Current
  • 3.3 LVPDB
    • 3.3.1 Bus Current
    • 3.3.2 Bus Voltage
    • 3.3.3 CP Current
    • 3.3.4 CP Voltage
    • 3.3.5 AF Current
    • 3.3.6 AF Voltage
    • 3.3.7 RF Current
    • 3.3.8 RF Voltage
  • 3.4 DCU
  • 3.5 ICS
    • 3.5.1 Buttons & Swtiches
  • 3.6 DART
    • 3.6.1 Measured Fan Speeds (Both DART1 and DART2)

1 Overview

Branches:

• main: Stores all files and latest changes.
• stm32: Stores FEB_CAN_ID.h file. This branch is a shared submodule for all STM32 projects.

STM32 Files:

• FEB_CAN_ID.h: A header file that stores all CAN Message IDs.
• FEB_CAN.c: A file that handles CAN library initialization and received message handling. Additional CAN files will build of this one. File contains template code for writing additional CAN files.
• FEB_CAN.h: Header file for FEB_CAN.c.

Other files:

• FEB_CAN_ID.csv: A CSV file that stores names of CAN messages without assigned CAN IDs. This file is used to generate dynamic CAN IDs.
• FEB_CAN_Static_ID.csv: A CSV file that sores names of CAN messages and their assigned CAN ID.
• generate.py: This file uses data from FEB_CAN_ID.csv and FEB_CAN_Static_ID.csv to generate FEB_CAN_ID.h.
• feb_can_id.py: A Python file that stores all CAN Message IDs.
• README.md: Documentation for the CAN Library.

2 Usage

2.1 Git Submodule

1. Add: Install submodule into STM32 project, in Core/Inc/FEB_CAN_Library. Example command for BMS project is provided below.

   git submodule add -b stm32 [email protected]:Formula-Electric-Berkeley/FEB_CAN_Library_SN3.git BMS/Core/Inc/FEB_CAN_Library
   

   Command template.

   git submodule add -b stm32 <CAN Library GitHub URL> project_name/Core/Inc/FEB_CAN_Library
   

2. Update: Run this command periodically to update the CAN library for STM32 projects.

   git submodule update --init --remote --recursive
   

2.2 Update Library

Updating the library is a 2 step process, across branches main and stm32.

Git Branch: main

1. Add CAN Message: To add a CAN message with a static CAN ID, update FEB_CAN_Static_ID.csv file. To add a CAN message without a static CAN ID, update the FEB_CAN_ID.csv file.
2. Generate: Run generate.py script. This will update the FEB_CAN_ID.h header file.
3. Documentation: Document the new CAN message in this readme file.
4. GitHub: Commit and push changes to GitHub.

Git Branch: stm32

1. Update: Fetch changes from main branch.

   git checkout main -- FEB_CAN_ID.h
   

2. GitHub: Commit and push changes to GitHub.

3 CAN Message Documentation

Note: Bytes and bits are 0-indexed. Multi-byte data is stored in Big-Endian format.

3.1 BMS

3.1.1 State

Byte	Value	Datatype
0	BMS State	uint8_t
1	Relay State	-
2	GPIO Sense	-

BMS State Value	BMS State
0	Startup
1	Standby
2	Balance
3	Charge
4	Precharge
5	Drive-Standby
6	Drive
7	Drive-Regen
8	Fault

Relay State Bit	Value
0	BMS Shutdown
1	AIR+
2	Precharge

GPIO Sense Bit	Value
0	AIR- Sense
1	AIR+ Sense
2	BMS Shutdown Sense
3	IMD Shutdown Sense
4	Charge Sense

3.1.2 Cell Data

Byte	Bit	Value	Unit	Datatype
0	7-5	Bank	-	uint8_t
0	4-0	Cell	-	uint8_t
1-2	-	Voltage	mV	uint16_t
3-4	-	Temperature	dC	int16_t
5	-	Flags	-	-

Bit	Flags
0	Under/Over Voltage
1	Under/Over Temperature
2	Balance
3	Disabled Temperature

3.1.3 Accumulator Voltage

Byte	Value	Unit	Datatype
0-1	Total Pack Voltage	mV	uint16_t
2-3	Min Cell Voltage	mV	uint16_t
4-5	Max Cell Voltage	mV	uint16_t

3.1.4 Accumulator Temperature

Byte	Value	Unit	Datatype
0-1	Average Cell Temperature	dC	int16_t
2-3	Min Cell Temperature	dC	int16_t
4-5	Max Cell Temperature	dC	int16_t

3.2 APPS

3.2.1 Normalized Brake

Byte	Value	Datatype
0-4	Normalized Brake	float

3.2.2 RMS Param Msg

Byte	Value	Datatype
0	addr	uint8_t
2	r/w command	boolean
3	NA	-
4-5	data	uint8_t
6-7	NA	-

R/W Command Value	State
0	Read
1	Write

Addr Value	State
20	Fault Clear
148	CAN Active Messages Lo Wor

3.2.3 RMS Command Msg

Byte	Value	Datatype
0-1	Torque Command	Torque
2-3	Speed Command	Angular Velocity
4	Direction	boolean
5.0	Inverter Enable	boolean
5.1	Inverter Discharge	boolean
5.2	Speedmode Enabled	boolean
6-7	Command Torque Limited	Torque

3.2.4 BSPD

Byte	Value	Datatype
0	BSPD State	uint8_t

BSPD State Value	BSPD State
0	False / Not Triggered
1	True / Triggered

3.2.5 Current

Byte	Value	Datatype
0-4	TPS Current	float

3.3 LVPDB

The LVPDB transmits 1 byte messages that correspond to the voltage and currents on the main bus, coolant pump, accumulator fans, or radiator fans.

3.3.1 Bus Current

Bus current should be measured to the second decimal place. Intended to be measured in mA

</tr>

Byte	Value	Datatype
1-2	Bus Current	int16_t

3.4 DCU

3.5 ICS

3.5.1 Buttons & Swtiches

The DASH_Breakout Board transmits a 1 byte message corresponding to status of the I/O on the I/O expander, the bits in the message are broken down in the table below:

Bit	Value	Datatype
0	Buzzer State	bool
1	Button 1 (Ready-To-Drive)	bool
2	Button 2	bool
3	Button 3	bool
4	Button 4	bool
5	Switch 1 (Coolant Pump)	bool
6	Switch 2 (Radiator Fans)	bool
7	Switch 3 (Accumulator Fans)	bool

3.6 DART

3.6.1 Measured Fan Speeds (Both DART1 and DART2)

Byte	Value	Datatype
0	Measured fan speed for fan 1, with 0 being fan off and 255 being fan at full speed	uint8_t
1	Equivalent for fan 2	uint8_t
2	Equivalent for fan 3	uint8_t
3	Equivalent for fan 4	uint8_t
4	Equivalent for fan 5	uint8_t