NB-IoT Module Series
BC66 Hardware Design
BC66_Hardware_Design 29 / 57
TXD
RXD
RI*
Module
GND
C1+
C1-
C2+
C2-
V+
VCC
GND
V-
3.3V
T1IN
T2IN
T3IN
T4IN
R1IN
R2IN
R3IN
R1OUT
R2OUT
R3OUT
T1OUT
T2OUT
T5OUT
T3OUT
T4OUT
T5IN
GND
GND
/R1OUT
1
2
3
4
5
7
8
9
GND
To PC Main Serial Port
GND
RS-232
Transceiver
6
Level Shifter
(1.8V~3.3V)
Figure 19: Sketch Map for RS-232 Interface Match
Please visit vendors
’ websites to select a suitable RS-232 transceiver, such as: http://www.exar.com and
http://www.maximintegrated.com.
1. Transistor circuit solution is not suitable for applications with high baud rates exceeding 460Kbps.
2.
“
” represents the test point of UART interfaces. It is also recommended to reserve the test points of
VBAT and PWRKEY, for convenient firmware upgrade and debugging when necessary.
3.
“*” means under development.
3.9. SPI Interface
BC66 provides one SPI master interface. The following table shows the pin definition of SPI interface.
NOTES
