Laird DVK-BT900-S Series, Руководство по интеграции оборудования

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BT900 Development Kit
Version 0.3
Embedded Wireless Solutions Support Center:
http://ews-support.lairdtech.com
www.lairdtech.com/wireless
18 Laird Technologies
Americas: +1-800-492-2320
Europe: +44-1628-858-940
Hong Kong: +852-2268-6567 x026
The buzzer (BZ1) ACTC SMD PIEZO BUZZER part number APD-1203-PQ1 can be disconnected from BT900 module by
micro-DIP switch CON15. Physical micro-DIP switch body has text “ON” on the closed side.
To drive the buzzer, configure SIO_12 as a digital output using
smart
BASIC GpioSetFunc(12,2,0) and then, for
example, write a 0 followed by a 1 to SIO_12 repeatedly in a loop.
Sample
smart
BASIC applications are available from a Laird FAE, or refer to bzt.buzzer.test.sb in the
smart
BASIC
sample application library on BT900 product pages at: https://github.com/LairdCP/BT900-Applications
6.2.2 Temperature Sensor
Figure 11: Temperature sensor
The temperature sensor (U1) can be disconnected from BT900 module by micro-DIP switch CON14. Physical
micro-DIP switch body has text “ON” on the closed side.
The temperature sensor (U1) can be disconnected from supply rail by cutting the solder bridge SB1.
The development board on-board temperature sensor (TI LM20BIM7 www.ti.com/lit/ds/symlink/lm20.pdf) has an
Analogue output that is connected to BT900 module pin SIO_21; but since the LM20BIM7 has an analogue output,
the BT900 module SIO_21 digital pin (DIO) must be configured as AIN analogue input (ADC). To configure the
SIO_21 pin from DIO pin to Alternate function AIN, see file “ts.temperature.sensor.sb” in the
smart
BASIC sample
application library on BT900 product pages at: https://github.com/LairdCP/BT900-Applications
Key specifications of the LM20BIM7:
Output type Analogue output
Accuracy at 30ºC ±1.5ºC ±4ºC (max)
Accuracy at 40ºC to +85ºC approx. ±2.5ºC ±5ºC (max)
Power supply voltage range +2.4 V to 5.5 V
Current Drain 10 uA (max)
Output impedance 160 Ohms (max)
LM20BIM7 datasheet states Temperature (T) to Voltage output (Vo) relationship approximated as a linear equation
(for temperature range of -40ºC to +85ºC):
Vo(mV) = -11.79mV/ºC x T + 1858.3
Table 2 gives calculated Vo versus temperature:
SB1
Solderbridge
1
1
2
2
C2
0.1uF,16V
R59
NOPOP (0R)
C1
0.1uF,16V
VCC_3V3
U1
2.4V,10uA,-55dC~+130dC
V+
4
GND
5
Vo
3
GND
2
NC
1
Temp_Sens
VCC_IO
R5
NOPOP (4.7K)
R4
470R
GND GND GND GND