Board components
Featured devices
The board features several NXP ICs:
MC33772: 6-Channel Li-Ion battery cell controller IC designed for automotive and industrial applications such as HEV, EV, ESS, UPS systems. The MC33772 allows ADC conversions on the differential cell voltages and currents as well as coulomb counting and temperature measurements. It features embedded balancing transistors and diagnostics to simplify applications. The device supports standard SPI and transformer isolated daisy chain communication (via MC33664) to an MCU for processing and control
S32K144: AEC-Q100 certified microcontroller for general purpose automotive applications. The S32K144 features an Arm® Cortex®- M4F core, 512 KB of Flash, CAN/CAN-FD controllers, security module complying with SHE specification and is offered in LQFP-48, LQFP-64, LQFP-100 and MAPBGA-100 packages supporting an ambient temperature range from -40°C up to 125°C
UJA1169: Mini high-speed CAN System Basis Chip (SBC) containing an ISO 11898-2:201x (upcoming merged ISO 11898-2/5/6) compliant HS-CAN transceiver and an integrated 5V or 3.3V 250 mA scalable supply (V1) for a microcontroller and/ or other loads. It also features a watchdog and a Serial Peripheral Interface (SPI). The UJA1169 can be operated in very low-current Standby and Sleep modes with bus and local wake-up capability
A1007: A1007 authentication IC is a secure solution built with many tamper resistant features and security countermeasures to deter common invasive and non-invasive attacks
NTAG5: NXP’s NTAG 5 boost shrinks the NFC footprint while adding AES security, so designers can deliver ultra-compact devices for use in IoT, consumer, and industrial applications
IC board location identifiers
The main ICs featured are listed in the table below:
Label
Description
Reference
U1
Battery Cell Controller (BCC)
U2
Micro-Controller Unit (MCU)
U3
System Basis Chip (SBC)
U4
Authentication
A1007
U5
Near-Field Communication (NFC)
Connectors
The following figure shows the location of the connectors on the board.
All connectors implemented on RDDRONE-BMS772 are detailed in the table below:
Label
Description
Manufacturer
Reference
Placed or DNP
JP1
Cell terminal connector
JST MFG. CO
SxB-XH-A(LF)(SN)
DNP
J1
External temperature sensor
JST MFG. CO
SM02B-GHS-TB(LF)(SN)
Populated
J2
JTAG debugger
-
E.g.: FTS-105-01-F-D from SAMTEC
Populated
J3
CAN bus
JST MFG. CO
SM04B-GHS-TB(LF)(SN)
Populated
J4
Battery power input
-
E.g.: FIT0588 from DFRobot
DNP
J5
Battery power output
-
E.g.: FIT0588 from DFRobot
DNP
J6
Reset jumper
FCI
68000-202HLF
Populated with jumper mounted
J18
SMBus (I²C slave bus)
JST MFG. CO
SM04B-GHS-TB(LF)(SN)
Populated
J19
DCD-LZ debugger
JST MFG. CO
SM07B-GHS-TB(LF)(SN)
Populated
J20
Additional CAN bus
JST MFG. CO
SM04B-GHS-TB(LF)(SN)
Populated
J21
MCU expansion header
HARWIN INC.
M50-3530842
DNP
J22
Wake jumper
FCI
68000-202HLF
DNP
J23
I²C master bus
FCI
68000-204HLF
Populated
Note: Hardware configuration of the board is done via 16 jumpers to solder (SJxx). See Cell terminal connection, Shunt resistor and External NFC antenna for more details.
Communication with Flight Management Unit
The RDDRONE-BMS772 board can communicate with a host device such as a PX4 Flight Management Unit (FMU) using the SMBus bus (can also be used as a simple I²C bus, connector J18) or the UAVCAN bus (can also be used as a simple CAN bus, connectors J3 and J20).
Note: For further information about UAVCAN, look for enablement in PX4.io software.
Programming and debug
There are two ways to program and debug the RDDRONE-BMS772 board:
through the DCD-LZ connector (J19)
through the JTAG connector (J2)
Note: The DCD-LZ combines a debug interface with a debug serial console. It is used on RDDRONE-FMUK66 (HoverGames). For more information see the HoverGames gitbook.
LED
The RDDRONE-BMS772 implements a programmable RGB LED. Various color combination and blink patterns can be used to indicate the state of the battery and system.
Button
The side button is a wake button, it connects the WAKE pin of the SBC to the ground when pressed. The J22 header placed in parallel of the side button can be used as an alternative if an extended or panel mount button is needed.
Display
An external display could be used to display important (battery) information. This display can be connected to J23, the I²C master bus. This header could be supplied with 3.3V (D34) or 5V (D35, default populated). By switching the diode, 3.3V or 5V could be used.
Some recent versions of the board may include a small common 0.91 inch OLED display using SSD1306 controller.
These displays work at both 3.3V and 5V. Software has been prepared but requires connection to the 3.3V domain (D34)
Double check the pinout configuration as they occasionally differ. Most use 1-GND, 2-
VCC, 3-SCL, 4-SDA and will connect directly to header J23 without modification.
Example of 0.91 inch OLED display using SSD1306 I2C display controller
External and additional components
External components
An optional external temperature sensor can be added onto the RDDRONE-BMS772 board using connector J1. An example of application for this external sensor can be to monitor the cells temperature inside the battery pack.
Additional components
Some components are included in the design but are not mounted on the RDDRONEBMS772 original board. They are marked "DNP" on the schematics and the BOM. The following table is giving the list of additional components that can be implemented in the design as well as their use:
Feature
Description
Label
Additional MOSFETs
Q3, Q4, Q7, Q8
Heatsinks
In order to dissipate more power, four additional heat-sinks can be mounted: two on the top side and two on the bottom side of the board. Recommended part is FK 244 08 D2 PAK
HS1, HS2, HS3, HS4
Optional termination resistor network on CAN bus
One 60.4 Ω resistor on each CAN line connected to a 4700 pF capacitor wired to the ground
R49, R50, C66
Capacitors on cell measurements connections
A filter can be added to the cell voltage measurements connections, according to the number of cells in use
C6, C12, C18, C22, C26, C29, C34
Capacitors on external temperature sensor
If the external temperature sensor is implemented, two capacitors can be added on the external temperature sensor low pass filter for more EMC demanding applications
C49, C54
Capacitor on cell balancing connections
Capacitors can be added on the cell balancing circuit for EMC, according to the number of cell in use
C99, C100, C101, C102, C103, C104, C105, C106, C107
External NFC antenna
Coil as an alternative option for the PCB NFC antenna for extended range operations
L2
Resistor on gate driver RS pin
Resistor to link RS pin on gate driver to MCU
R99
MCU expansion header
Additional MCU pins are wired to a 1x8 header slot. Potential to use additional battery level LEDs, emergency button, etc.
J21
Wake jumper
Jumper for SBC wake-up. In parallel of the button
J22
Test point definitions
The following figure shows the location of the test points on the board.
Label
Signal name
Description
TP1
OVERCURRENT
Overcurrent signal
TP2
AUTH_NFC_SCL
Authentication and NFC I²C bus clock signal
TP3
AUTH_NFC_SDA
Authentication and NFC I²C bus data signal
TP4
VCC_3V3_SBC
SBC 3.3 V regulator output
TP5
RST_N
Reset signal (active low)
TP6
CAN_LO
CAN Low signal
TP7
CAN_HI
CAN High signal
TP8
VCC_3V3_LDO1
LDO 3.3 V regulator output
TP9
SMBUS_SCL
SMBus I²C bus clock signal
TP10
SMBUS_SDA
SMBus I²C bus data signal
TP11
VBAT_IN
Power input
TP12
VBAT_OUT
Power output
TP13
GND
Ground reference of the device
TP14
N/A
Power switches gate command
TP16
BCC_MISO
BCC SPI MISO line
TP17
BCC_CS
BCC SPI chip select
TP18
BCC_SCLK
BCC SPI clock signal
TP19
BCC_MOSI
BCC SPI MOSI line
TP20
SBC_CS
SBC SPI chip select
TP21
SBC_MISO
SBC SPI MISO line
TP22
SBC_MOSI
SBC SPI MOSI line
TP23
SBC_SCLK
SBC SPI clock signal
TP24
VCC_HARVEST
The VOUT pin of the NTAG (voltage harvest)
TP25
N/A
Connected to J18[1] of SMBus connector
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