BISM2 Bluetooth™

Hardware Integration Guide

Embedded Wireless Solutions Support

Center: http://ews-

support.lairdtech.com

www.lairdtech.com/bluetooth

8

Laird

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Pin 8 (UART_DCD) is active low. It is normally 3.3v. When a connection is live this pin is low. This

means that when this pin is converted to RS232 voltage levels it will have the correct voltage level for

assertion.

Pin 10 (UART_DSR) is an input, with active low logic. It should be connected to the DTR output of

the host. When the BISM2 module is in high speed mode (See definition for S Register 507), this pin

should be asserted by the host to ensure that the connection is maintained. A deassertion is taken to

mean that the connection should be dropped, or an online command mode is being requested.

Pin 27 (VCC_3V3 monitor) may only be used for monitoring purposes. It must not be used as a

current source.

The GPIO pins can be accessed using S Registers 621 to 628. GPIO4 is connected to an LED on the

module. If these I/O pins are set for input, then the LED will be driven by the host and appropriate

drive current requirements must be satisfied. A Logic 1 switches on the LED. GPIO3 is also used for

DTR output (active low). See S Register 552 & 553.

Analogue 0 and 1 should not exceed 1.8v and S Registers 701 and 702 are used to access them.

3.3 Electrical Specifications

3.3.1 Absolute Maximum Ratings

Absolute maximum ratings for supply voltage and voltages on digital and analogue pins of the module are

listed below.

WARNING: Exceeding these values causes permanent damage to the module.

Parameter

Min

Max

Unit

Peak current of power

supply

0

100

mA

Voltage at digital pins

-0.3

3.7

V

Voltage at POWER pin

3.6

7

V

3.3.2 Recommended Operating Parameters

3.3.2.1

Power Supply

Signal Name

Pin No.

I/O

Voltage Level

Comments

Vcc

29

I

3.6 V to 7.0 V

GND

11, 15, 18, 30, 36, 38

6 Ground terminals to be attached in

parallel

VCC_3V3

27

O

3.3 V typical

For monitoring only. No current source.

3.3.2.2

RS232 Interface

Signal Name

Pin No.

I/O

Voltage Level

Comments

UART_TX

21

O

UART_RX

25

I

6 Ground terminals to be attached in parallel