E22-400M33S User Manual
8
14
BUSY
Output
For status indication (see SX1268 manual for details)
15
NRST
Input
Chip reset trigger Input pin, active low
16
MISO
Output
SPI Data Output Pin
17
MOSI
Input
SPI Data Input Pin
18
SCK
Input
SPI Clock Input Pin
19
NSS
Input
Module chip select pin to start an SPI communication
20
GND
Ground wire, connected to power reference ground
21
ANT
Antenna connector, stamp hole (50Ω characteristic impedance)
22
GND
Ground wire, connected to power reference ground
4. Basic operation
4.1 Hardware Design
Recommend using a DC regulated power supply to power the module with as small a ripple coefficient as possible,
and the module needs to be reliably grounded.
Please pay attention to the correct connection of the positive and negative terminals of the power supply, as a
reversed connection may cause permanent damage to the module.
Please check the power supply to ensure that it is between the recommended supply voltage, if it exceeds the
maximum value it may cause permanent damage to the module.
Please check the stability of the power supply, the voltage should not fluctuate significantly and frequently.
When designing the power supply circuit for the module, it is often recommended to retain more than 30% margin
to have the whole machine conducive to long-term stable operation.
modules should be as far away as possible from the power supply, transformers, high-frequency alignments and
other parts of the electromagnetic interference.
High-frequency digital alignment, high-frequency analog alignment, power supply alignment must be avoided
below the module, if it is necessary to pass below the module, assuming that the module is soldered in the Top
Layer, in the module contact part of the Top Layer pavement copper (all pavement copper and good grounding),
must be close to the digital part of the module and alignment in the Bottom Layer.
Assuming that the module is soldered or placed in the Top Layer, it is also wrong to run wires randomly in the
Bottom Layer or other layers, which will affect the spurious and reception sensitivity of the module to varying
degrees.
Assuming that there are large electromagnetic interference devices around the module will also greatly affect the
performance of the module, according to the strength of the interference is recommended to be properly away from
the module, if the situation allows the appropriate isolation and shielding.
Assuming that there are large electromagnetic interference alignments around the module (high-frequency digital,
high-frequency analog, power supply alignments) will also greatly affect the performance of the module, according
to the intensity of the interference, it is recommended to keep away from the module, and if the situation permits,
