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100021008
7.2
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03/Apr/2020
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Instruction
4(21)
All information contained within this document is proprietary to Fingerprint Cards AB.
2
Development Kit Hardware
2.1 BM-Lite Module
BM-Lite module (Part number: 100018754)
The BM-Lite module has a standard 10 pin 0.5 mm pitch Flat Flex Connector as main interface.
The pin-out is described in the table below.
Pin
number
Signal
Name
Function
Description
Min.
Voltage
[V]
Max.
Voltage
[V]
Max.
frequency
[MHz]
1
GND
Supply
GND pin
0
0
DC
2
SPICLK
Digital in
Serial clock used for SPI
GND
3.6
20
3
MISO
Digital out
The SPI Serial tri-state output which is
enabled with CS_N low
GND
3.6
SPICLK
4
MOSI
Digital in
The SPI Serial data Input
GND
3.6
SPICLK
5
CS_N
Digital in
Chip Select active when low
GND
3.6
~0
6
IRQ
Digital out
Interrupt request output (SPI only)
GND
3.6
~0
7
RST_N
Digital in
Reset module. Active low*.
GND
3.6
~0
8
UART_RX
Digital in
UART receive data pin
GND
3.6
921600** (Baud)
9
UART_TX
Digital out
UART transmit data pin
GND
3.6
921600** (Baud)
10
VDDIO
Supply
Core supply voltage. Typical 3.3V
3.0
3.6
DC
BM-Lite interface
* Keep low at least 20µs to reset whole module
**Default baud rate is 115200
BM-Lite FFC connector. Pin 1 is to the left.
BM-Lite supports both UART and SPI interfaces. Both interfaces are enabled at power-on, but
only one of them can be used at the same time. BM-Lite will auto detect which interface is
being used by detecting data traffic. It is therefore important that the input signals for the
unused interface are pulled into a fixed state to avoid interference.
2.1.1 SPI Interface
When using the SPI interface, the
UART RX
signal should be held at a fixed state to avoid
unintentional interference on the UART interface.
