BT900-Sx Hardware Integration Guide
Intelligent BTv4.0 Dual Mode Module
Embedded Wireless Solutions Support Center:
http://ews-support.lairdtech.com
www.lairdtech.com/bluetooth
21
Americas: +1-800-492-2320
Europe: +44-1628-858-940
Hong Kong: +852 2923 0610
5.2
Clocks and Timers
5.2.1
Clocks
The integrated high accuracy (+/-20 ppm) 32.768 kHz crystal oscillator provides protocol timing and helps
with radio power consumption in the system Standby Doze/Deep sleep modes by reducing the time that the
RX window must be open. Standard accuracy clocks tend to have lower ac/-250 ppm.
The integrated high accuracy 26 MHz (+/-10 ppm) crystal oscillator helps with Radio operation and also helps
reduce power consumption in the Active modes.
5.2.2
Timers
In keeping with the event driven paradigm of
smart
BASIC, the timer subsystem enables the writing of
smart
BASIC which allows the generation of future events based on timeouts.
Regular Timer – There are eight built-in timers (regular timer) derived from a single multifunction timer
clock which are controlled solely by
smart
BASIC functions. The resolution of the regular timer is
dependent on the selected system clock frequency can be obtained from Table 10.
Table 10: System Clock and Tick Count Period
System Clock (MHz)
Tick Count Period (uS)
40
6.4
20
12.8
4
64
Tick Timer – This is a 31-bit free running counter that increments every one millisecond. The resolution
of this counter is dependent on the selected system clock frequency and can be obtained from Table
10.
Refer to the
smart
BASIC User Manual for more information.
5.3
Memory for
smart
BASIC Application Code and Data
Up to approximately 48 Kb of data memory is available for the
smart
BASIC application script and up to 4 Kb
is available for data.
5.4
RF
2402–2480 MHz Bluetooth 4.0 Dual Mode (BT and BLE); 1 Mbps to 3 Mbps over the air data rate.
TX output power of +8 dBm programmable (via
smart
BASIC command) to -20 dBm in steps of four dB.
Receiver (with integrated channel filters) to achieve maximum sensitivity -90 dBm @ 1 Mbps BLE or
Classic BT, 2 Mbps, 3 Mbps).
RF conducted interface available in 2-ways:
-
BT900-SA: RF connected to on-board antenna on the BT900-SA
-
BT900-SC: RF connected to on-board uFL RF connector on the BT900-SC
Antenna options:
-
Integrated monopole chip antenna on the BT900-SA
-
External dipole antenna connected with to uFL RF connector on the BT900-SC.
