JbdBms library for Arduino v0.2

This is a library for working with battery manager system JBD. If you can configure your BMS trough the JBDTool, then this code will suit you. See my project in hack a day.

Hardware

Connect UART pins to an Arduino board DIGITAL pins:

• RX
• TX
• GND

Attention! UART GND circuit is electrically isolated from the power GND BMS.

Usage

Initialization

#include "JbdBms.hpp"

JbdBms myBms(6,7); // RX, TX

void setup()
{
  myBms.begin();
}

Reading basic data from BMS

if (myBms.readBmsData()== true)
{
  // use the get-functions
}

After calling readBmsData () request is sent to the BMS. In case of a successful read response, the method returns true.

You can work with the data obtained using the get-functions: getChargePercentage(), getCurrent(), getProtectionState().

Get-functions

Charge percentage

myBms.getChargePercentage();

This method return the float value.

Consumption current

myBms.getCurrent();

This method return the float value.

Protection state

myBms.getProtectionState();

This method return the uint16_t value.

If this value is not 0, then BMS detected some errors. You can check this value on the mask by using the following error values:

#define BMS_STATUS_OK				0
#define BMS_STATUS_CELL_OVP			1
#define BMS_STATUS_CELL_UVP			2		///< Power off
#define BMS_STATUS_PACK_OVP			4
#define BMS_STATUS_PACK_UVP			8		///< Power off
#define BMS_STATUS_CHG_OTP			16
#define BMS_STATUS_CHG_UTP			32
#define BMS_STATUS_DSG_OTP			64		///< Power off
#define BMS_STATUS_DSG_UTP			128		///< Power off
#define BMS_STATUS_CHG_OCP			256
#define BMS_STATUS_DSG_OCP			512		///< Power off
#define BMS_STATUS_SHORT_CIRCOUT	1024	///< Power off
#define BMS_STATUS_AFE_ERROR		2048
#define BMS_STATUS_SOFT_LOCK		4096
#define BMS_STATUS_CHGOVERTIME		8192
#define BMS_STATUS_DSGOVERTIME		16384	///< Power off
#define BMS_POWER_OFF_ERRORS		0x46CA

Some errors lead to power down (labeled "Power off"). If you want to read them a device that is powered from the battery, it will not work.

Cycle counter

int cycleCount = myBms.getCycle();

This method return the integer value.

Data from temperature sensors

Depending on your BMS, the sensor can be located either on the board or be external. Find it out empirically.

float temp1 = myBms.getTemp1();
float temp2 = myBms.getTemp2();

Reading voltage on the cells

if (myBms.readPackData()== true)
{
  // use the get-functions
}

After calling readPackData () request is sent to the BMS. In case of a successful read response, the method returns true.

You can work with the data obtained using the get-function getPackCellInfo().

Voltage on the cells

packCellInfoStruct cellInfo;
cellInfo = myBms.getPackCellInfo();

This method return the packCellInfoStruct. Structure structure is presented below:

typedef struct packCellInfoStruct{
  uint8_t NumOfCells;
  uint16_t CellVoltage[15]; // Max 16 Cell BMS
  uint16_t CellLow; // Minimal voltage in cells
  uint16_t CellHigh; // Maximal voltage in cells
  uint16_t CellDiff; // difference between highest and lowest
  uint16_t CellAvg; // Average voltage in cells
} packCellInfoStruct;