Semtech E28-2G4T27SX User manual

User Manual
E28-2G4T27SX

E28-2G4T27SX User Manual
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Contents
Contents ····················································································································································································································································1
1.Product Overview.................................................................................................................................................................................. 2
1.1 Brief Introduction.......................................................................................................................................................................... 2
1.3 Application ..................................................................................................................................................................................... 2
2. Technical Parameters.......................................................................................................................................................................... 2
2.1 Limit parameter ............................................................................................................................................................................. 2
2.2 Operating parameter..................................................................................................................................................................... 3
3. Mechanical Characteristics................................................................................................................................................................ 4
3.1. Dimension Plan ............................................................................................................................................................................ 4
3.2. Pin Definition................................................................................................................................................................................ 5
4. Recommended Connection Diagram............................................................................................................................................... 6
5. Functional Description........................................................................................................................................................................ 6
5.1. Fixed Transmission...................................................................................................................................................................... 6
5.2. Broadcast........................................................................................................................................................................................ 6
5.3. Broadcast Address ....................................................................................................................................................................... 6
5.4. Monitor Address........................................................................................................................................................................... 6
5.5. Module Reset................................................................................................................................................................................ 6
5.6. AUX Description ......................................................................................................................................................................... 7
5.6.1 Indication of serial output.................................................................................................................................................... 7
5.6.2 Indication of wireless transmission................................................................................................................................... 7
5.6.3 Module in configuration process....................................................................................................................................... 7
6. Operation Modes.................................................................................................................................................................................. 8
6.1. Mode Switch................................................................................................................................................................................. 8
6.2. Transmission Mode (Mode 0)................................................................................................................................................... 8
6.3. RSSI Mode (Mode 1).................................................................................................................................................................. 8
6.4. Ranging Mode (Mode 2)............................................................................................................................................................ 8
6.5. Configuration mode (Mode 3)................................................................................................................................................... 9
7. Command Format ..............................................................................................................................................................................10
7.1. Default parameter values..........................................................................................................................................................10
7.2. Reading Operating Parameters................................................................................................................................................10
7.3. Reading Version Number......................................................................................................................................................... 10
7.4. Reset Command .........................................................................................................................................................................11
7.5. Parameter Configuration Commands ....................................................................................................................................11
8. Hardware design................................................................................................................................................................................. 13
9. FAQ....................................................................................................................................................................................................... 14
9.1 Communication range is too short....................................................................................................................................... 14
9.2 Module is easy to damage........................................................................................................................................................14
9.3 BER(Bit Error Rate) is high..................................................................................................................................................14
10. Production Guidance.......................................................................................................................................................................15
10.1 Reflow soldering temperature................................................................................................................................................ 15
10.2 Reflow soldering curve............................................................................................................................................................15
11. Package for batch order..................................................................................................................................................................16
Revision history...................................................................................................................................................................................... 16
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1.Product Overview
1.1 Brief Introduction
E28-2G4T27SX is an UART module based on SEMTECH SX1281, it adopts transparent transmission and works at 2.4GHz
band. It adopts FSK modulations. It features SMD packing compatible with 3.3V and 5V IO port voltage.
1.2 Features
Support FSK modulation;
Supporting high-speed continuous transmission, data without subcontracting;
Support RSSI for evaluating signal quality；
Supports air wake-up, low power consumption,suitable for battery power supply solution;
Support fixed transmission/broadcast/monitoring；
Communication distance tested is up to 5km in ideal condition;；
Maximum transmitting power of 20.3dBm, Software adjustable；
Support the global license-free ISM 2.4GHz；
Low power consumption for battery supplied applications；
Support 2.3V~5.5V power supply, power supply over 5.5V can guarantee the best performance；
Industrial grade standard design, support -40 ~ 85 °C for working over a long time；
1.3Application
Smart Home and Industrial Sensors;
Security system, location System
Wireless remote control; UAV；
Wireless Game Remote Controller
Health care products；
Wireless voice, wireless headset;
Automotive industry applications.
2. Technical Parameters
2.1 Limit parameter
Main parameter Performance Note

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Min Max
Voltage supply [V] 2.3 5.5 Voltage over 5.5V will cause permanent damage to
module
Blocking power [dBm] -10 Chances of burn is slim when modules are used in
short distance
Operating temperature [℃] -40 +85 -
2.2 Operating parameter
Main parameter Performance Note
Min Typ Max
Voltage supply [V] 2.35.0 5.5 ≥5.0V ensures output power
Communication level [V] -3.3-For 5V TTL, it may be at risk of burning down
Operating temperature [℃] -40 -+85 -
Frequency [MHz] 2402-2480 ISM band
Power
consumption
Transmitting current
[mA] -500 -Instant power consumption
Receiving current
[mA] -27 --
Turn-off current
[μA] -10 -Software is shut down
Transmitting power [dBm] 20 20.3 21
Receiving sensitivity [dBm] -130 -132 -134 Air data rate: 100Kbps
Air data rate（bps）1k 100k2M Defined by user via programming
Main parameter Description Note
Distance 5000m Test condition：clear and open area，antenna
height: 2.5m，air data rate: 100kbps
FIFO 121 Btye Max. Transmitting length per packet
221 Btye Continuous transmission mode
Cache 2048 Byte -
Modulation FSK -
Interface UART TTL
Package SMD -
Connector 1.27mm -
Size 40.5*25mm -
Antenna Stamp hole 50Ω Impedance，External SMA header via 19 pins

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3. Mechanical Characteristics
3.1. Dimension Plan

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3.2. Pin Definition
Pin No. Pin Name Pin Direction Function
1 GND Ground Ground
2 NC - cannot be floated, can be grounded if not used
3 NC - cannot be floated, can be grounded if not used
4 NC - cannot be floated, can be grounded if not used
5 NC - cannot be floated, can be grounded if not used
6 NC - cannot be floated, can be grounded if not used
7 NC - cannot be floated, can be grounded if not used
8 GND Ground Ground
9 NC - cannot be floated, can be grounded if not used
10 GND Ground Ground
11 VCC - Module power source positive reference.
Voltage range: 2.5V ~ 5.5V DC
12 AUX Input
Used to indicate the module operation status, when user wakes up the
external MCU,it outputs low level during initialization after power on
and self-check, can be configured as open-drain output or push-pull
output, please refer to Parameter Configuration.
(can be floated)
13 TXD Output
TTL serial input, connected to external TXD output pin. Can be
configured as open-drain or pull-up input, please refer to Parameter
Configuration.
14 RXD Output
TTL serial input, connected to external TXD output pin;
It can be configured as drain open circuit or pull-up input. See parameter
setting for details
15 M1 Input M2, M1 and M0 determine eight working modes
16 M0 Input M2, M1 and M0 determine eight working modes
17 M2 Input M2, M1 and M0 determine eight working modes
18 GND Ground Ground
19 ANT - Antenna interface (50 Ω characteristic impedance；External SMA
header )
20 GND Ground Ground
21 GND Ground Ground
22 NC - cannot be floated, can be grounded if not used
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4. Recommended Connection Diagram
5. Functional Description
5.1. Broadcast Address
i.e.: set the address of moduleAas 0xFFFF or 0x0000 and channel as 0x04.
When set A as transmitter (same mode, transparent transmission on), all modules with channel 0x04 will receive broadcast
data.
5.2. Monitor Address
i.,e.: set the address of module A as 0xFFFF or 0x0000 and channel as 0x04.
When set A as receiver, it will receive the data transmitted by modules with channel 0x04.
5.3. Module Reset
When the module is powered on, the AUX output will go to a low level immediately, the module conducts hardware
self-check and sets the operating mode on the basis of the user parameters (M0 M1). During the process, the AUX level
remains low. After the process completed, the AUX outputs high a level and starts to work as per the operating mode
indicated by the combined state of M1 and M0. The user needs to wait until the AUX rising edge is high, indicating the
module is ready for normal work.
No. Brief description for module-MCU connection (STM8L MCU as example)
1 The wireless UART module adopts TTL level, please connect to MCU with TTL level.
2 For some 5V MCU, 4~10K pull-up resistor may need to be added at the TXD and AUX pins of the module.

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5.4. AUX Description
AUX Pin can be used as indication for wireless send & receive buffer and self-check. It can indicate whether there is data
that is yet to send via wireless or whether all wireless data has been sent through UART, or whether the module is still in the
process of self-check initialization.
5.6.1 Indication of serial output
Used to wake up the external MCU (note: AUX indicates no delay under continuous mode)
5.6.2 Indication of wireless transmission
Under sub-packet transmission mode, the internal buffer size is determined by the sub-packet size, if the packet length is 221
bytes, then the buffer size will be 2048 bytes, when AUX=1, user could continuously initiate transmitting of no more than
2048 bytes.
Under continuous transmission mode, AUX=1 means the module is busy, but it is not applicable for waking up external
MCU, because the data transmission is very quick under continuous transmission mode.
AUX=1 means all serial data is transmitted through RF, and the module is at idle state.
5.6.3 Module in configuration process
Only occurs when resetting or when exiting sleep mode
Mode（0-3）M2 M1 M0 Introduction Remarks
0 - Transmission Mode 1 0 0
Serial port on, RF on, continuous
transparent transmission
The air data rate can be manually configured and
automatically adjusted along with baud rate values；
the baud rates on both sides must be the same under
continuous transmission mode

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6. Operation Modes
The module has 4 operation modes, which are determined accordingly by pins M0, M1. Please refer to below instructions:
6.1. Mode Switch
User could determine the module operation mode through the combination of high-low level of M2, M1 and M0. Mode
switch can be controlled through the GPIO of the MCU.
When M2, M1 and M0 changed and the module is in idle state (AUX at high level), it can starts to work normally under new
mode, if serial data not transmitted completely, it will enter new mode after all data is transmitted; if the module receives
data and send out through serial port, the module will enter new mode after the data is transmitted completely; so mode
switch will only be valid when AUX outputs 1, or switch will be delayed.
i.e.: under mode 2 or mode 4, when user inputs large amount of data continuously and conducts mode switch, the mode
switch is invalid; the module will conduct new mode check after all data is transmitted; so, users are recommended to check
theAUX pin status and conduct mode switch 2ms later when AUX outputs high level.
When the module enters configuration mode from other modes, it will enter sleep mode when all data is processed
completely (both TX and RX). This feature can be used for quick sleep to save energy; i.e.: the transmitter works under mode
0 and the user send serial data“12345”, then the user does not need to wait till the AUX enters idle state (high level) and
directly switches to sleep mode and put the user main MCU into sleep mode, the module will automatically enter sleep mode
1ms later when all data is processed so as to save the MCU working time and lower energy consumption.
Similarly, this feature can be utilized for any mode switch, the module will enter new mode automatically within 1ms when
current even is processed completely, which saves the user’s efforts in checking AUX status and enables quick mode switch;
for example, when switching from transmitting mode to receiving mode, the user MCU could enter sleep mode before mode
switch, mode switch can be made by acquiring AUX change with external interrupt function.
This operation is very flexible and efficient, it is designed based on convenient MCU operation, and it could ease the
operation load of the entire system and increase the operation efficiency and lower the energy consumption.
6.2. Transmission Mode (Mode 0)
Under this mode, transparent transmission is available, that means the data transmitted from the transmitter will be received
by the receiver in the original format. Under normal mode, the two sides could communicate with each other normally based
on same air data rate, address and channel; under continuous transmission mode, the baud rates on both sides must be the
same, it supports large file continuous transmission under baud rate from 1200bps ~ 115200bps.
6.3. RSSI Mode (Mode 1)
Under this mode, the module will output current RSSI value of 2.4GHz signal every 100ms so as to check the channel quality,
the value is in HEX compliment format.
6.4. Ranging Mode (Mode 2)
(Reserved)
1 - RSSI Mode 1 0 1 Serial port on, RF on, RSSI on The module outputs RSSI value
through serial port
every 100ms
2 – Ranging Mode 1 1 0 Reserved -
3 -Configuration
Mode 1 1 1 Serial port on ，RF off, parameter configuration Baud rate is fixed as 9600 8N1
4 – Power Level 0 x x Power Level setting: channel 17 -

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6.5. Configuration mode (Mode 3)
Under this mode, Baud rate is fixed as 9600 8N1