BTM402-03 Laird Technologies, BTM402-03 Datasheet - Page 17

• Manufacturer Part Number: BTM402-03
• Description: MODULE, BLUETOOTH, BISM2 PA, 3.6V
• Manufacturer: Laird Technologies

Specifications of BTM402-03

• Compliance Standard: CE, FCC, IC, R, TTE
• Supply Voltage Range: 3.3V To 5V
• Physical Interfaces: UART
• Data Rate: 300Kbps
• Transmit Power: 65mW
• Receiving Signal Range: -87dBm
• Operating Temperature: RoHS Compliant
• Operating Temperature Range: -10°C To +85°C
• Rohs Compliant: Yes

9. Application Examples
9.1
A serial port has DTR, DSR, RTS, CTS, DCD and RI control lines. RTS and CTS are locally controlled to
prevent local buffer overflow.
The status of DTR, DRS, DCD and RI can be exchanged with the remote peer device. If for example,
the DTR/DSR lines are to be exchanged between the two peers to simulate the performance of a
physical cable, then it is possible to do so. Refer to the description for S Registers 551, 552 and 553
for more details.
Just as a telephony modem has control and status lines, the Module also provides for 6 control and
status lines as per the table below. The direction column is as seen from the module’s viewpoint.
The first four lines are under program control. These use four of the GPIO pins and are mapped to
I/O as per the table below. The last two are under control of the UART driver and their functionality is
always enabled.
Some serial implementations link CTS and RTS to remove the need for handshaking. EZURiO do not
recommend linking CTS and RTS other than for testing and prototyping. If these pins are linked and
the host sends data at the point that the Bluetooth Serial Module deasserts its RTS signal, then there
is a significant risk that internal receive buffers will overflow which could lead to an internal processor
crash. This will lead to a drop in connection and may require a power cycle to reset the module.
EZURiO recommend that the correct CTS/RTS handshaking protocol be adhered to for proper
operation.
DSH_BTM404_0v5 BISM2 3V3 PA Data Sheet.DOC
IN or OUT *
IN or OUT *
IN
OUT
IN
OUT
* configurable with S register 552
Direction
IN/OUT
IN/OUT
IN
IN/OUT
IN/OUT
IN/OUT
IN/OUT
IN/OUT
IN/OUT
IN/OUT
Direction
RS232 Modem Signals
Connector Pin Label
UART_RI
UART_DCD
UART_DSR
GPIO3/UART_DTR
GPIO4
GPIO5
GPIO6
GPIO7
GPIO8
GPIO9
RI also known as CI (Ring Indicate)
DCD (Data Carrier Detect)
DSR (Data Set ready)
DTR (Data Terminal Ready)
CTS (Clear to Send)
RTS (Request to Send)
Function
Function
Input/Output from module
Input/Output from module
Input to Module
General Purpose I/O (or DTR functionality)
General Purpose I/O
General Purpose I/O
General Purpose I/O
General Purpose I/O
General Purpose I/O
General Purpose I/O
17
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