Software Programming; Faq; Communication Range Is Too Short - Ebyte E22-900M22S User Manual

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parts with large electromagnetic interference.
High-frequency digital traces, high-frequency analog traces, and power traces must be avoided under the module. If
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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(All copper-covered and well grounded), and must be close to
the digital part of the module and routed in the Bottom Layer.
Assuming the module is soldered or placed in the Top Layer, it is also wrong to randomly route the Bottom Layer or
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other layers, which will affect the module's spurs and receiving sensitivity to varying degrees.
Assume that there are traces with large electromagnetic interference around the module (high-frequency digital,
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high-frequency analog, power trace), which will greatly affect the performance of the module. It is recommended to
stay away from the module according to the strength of the interference. If necessary, appropriate isolation and
shielding can be done;
If the communication line uses a 5V level, a 1k-5.1k resistor must be connected in series (not recommended, there is
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still a risk of damage).
Try to stay away from some physical layers and also have a 2.4GHz TTL protocol, for example: USB3.0
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The antenna mounting structure has a great influence on the performance of the module. It is necessary to ensure
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that the antenna is exposed, preferably vertically upward. When the module is mounted inside the case, use a good
antenna extension cable to extend the antenna to the outside of the case.
The antenna must not be installed inside the metal case, which will greatly reduce the transmission distance.
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It is recommended to add a 200R protection resistor to the RXD/TXD of the external MCU.
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4.2 Software Programming

Its driving mode is exactly the same as SX1268/SX1262. Users can operate according to SX1268/SX1262 chip
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datasheet.
DIO1 and DIO2 are general-purpose IO ports, which can be configured into multiple functions. DIO2 can be
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connected to TXEN and not connected to the MCU's IO port. It can be used to control the RF switch transmission.
If not used, you can hang it. For details, see the SX1262 manual.
DIO 3 is used to supply 32 MHz TCXO crystal oscillator.
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5. FAQ

5.1 Communication range is too short

The communication distance will be affected when obstacle exists.
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Data lose rate will be affected by temperature, humidity and co-channel interference.
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The ground will absorb and reflect wireless radio wave, so the performance will be poor when testing near ground.
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Sea water has great ability in absorbing wireless radio wave, so performance will be poor when testing near the sea.
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The signal will be affected when the antenna is near metal object or put in a metal case.
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Power register was set incorrectly, air data rate is set as too high (the higher the air data rate, the shorter the
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distance).
When the power supply at room temperature is lower than the recommended low voltage, the lower the voltage is,
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the lower the transmitting power is.
Due to antenna quality or poor matching between antenna and module.
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E22-900M22S User manual
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