Chengdu Ebyte Electronic Technology Co., Ltd.
Copyright ©2012–2021
,
Chengdu Ebyte Electronic Technology Co.,Ltd.
6
No.
Name
Direction
Function
1
GND
Ground
2
VCC
Power supply
:
1.8~ 3.6 V DC, 3.3V is recommended
3
GPIO0
output
GPIO
(
see more from SI4438 datasheet
)
4
GPIO1
output
GPIO
(
see more from SI4438 datasheet
)
5
IRQ
output
SPI interrupt request
6
SCK
input
Serial Clock Input
7
MISO
output
SPI master output slave input
8
MOSI
input
SPI master input slave output
9
nSEL
input
SPI Chip select for starting SPI communication
10
SDN
Shutdown Input Pin. It is low level when working
(See SI4438 manual for more details)
11
ANT
Antenna
12
GND
Ground
4. Basic operation
4.1 Hardware design
It is recommended to use a DC stabilized power supply. The power supply ripple factor is as small as possible, and
the module needs to be reliably grounded.
;
Please pay attention to the correct connection of the positive and negative poles of the power supply. Reverse
connection may cause permanent damage to the module
;
Please check the power supply to ensure it is within the recommended voltage otherwise when it exceeds the
maximum value the module will be permanently damaged
;
Please check the stability of the power supply, the voltage can not be fluctuated frequently
;
When designing the power supply circuit for the module, it is often recommended to reserve more than 30% of the
margin, so the whole machine is beneficial for long-term stable operation.
;
The module should be as far away as possible from the power supply, transformers, high-frequency wiring and other
parts with large electromagnetic interference.
;
High-frequency digital routing, high-frequency analog routing, and power routing must be avoided under the
module. If it is necessary to pass through the module, assume that the module is soldered to the Top Layer, and the
copper is spread on the Top Layer of the module contact part(well grounded), it must be close to the digital part of
the module and routed in the Bottom Layer
;
Assuming the module is soldered or placed over the Top Layer, it is wrong to randomly route over the Bottom Layer
or other layers, which will affect the module's spurs and receiving sensitivity to varying degrees
;
It is assumed that there are devices with large electromagnetic interference around the module that will greatly