rf-42uh sx1278 433 mhz lora module · 2020. 8. 28. · rf-42uh sx1278 433 mhz lora module version...
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RF-42UH SX1278 433 MHz LoRa Module
Version 1.3
Shenzhen RF-star Technology Co., Ltd.
Jan. 19th, 2020
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RF-42UH
www.szrfstar.com V1.3 - Jan., 2020
Shenzhen RF-star Technology Co., Ltd. Page 1 of 34
RF-star LoRa Module List
Chipset Model Antenna Dimension
(mm) Package
Frequency
(MHz)
TX Power
(dBm)
Range
(Km) Photo
ASR6501 RF-
AL42UH Half-hole 13.9 13.9 Half-hole 433 22 3
ASR6505 RF-
AL42UHB2 Half-hole 18.3 18.3 Half-hole 433 22 3
SX1278
RF-42UH Half-hole /
IPEX 16 26 Half-hole 433 18 3/4.5
RF-42UP SMA 21.1 36 DIP 433 18 3
RF-42SH Half-hole 16 16 Half-hole 433 18 3
RF-43UH Half-hole /
IPEX 25 40.3 Half-hole 433 27 10 Contact Me
RF-43UP SMA 24 43 Half-hole 433 27 10
RF-43SH Half-hole 25 40 DIP 433 27 10 Contact Me
SX1276
RF-82UH Half-hole /
IPEX 16 26 Half-hole
868
915 18 3/4.5
RF-82UP SMA 21.1 36 DIP 868 18 3
RF-82SH Half-hole 16 16 Half-hole 915 18 3
RF-83UH Half-hole /
IPEX 25 40.3 Half-hole 868 27 10 Contact Me
RF-83UP SMA 24 43 DIP 915 27 10 Contact Me
RF-83SH Half-hole 25 40 Half-hole 868 27 10
Note:
1. The communication distance is the longest distance obtained by testing the module's maximum transmission power
in an open and interference-free environment in sunny weather.
2. Click the picture to jump to buy modules.
http://www.szrfstar.com/https://www.alibaba.com/product-detail/RF-star-433MHz-LoraWAN-LinkWAN-UART_1600103616154.html?spm=a2747.manage.0.0.1c7171d2j4q4cVhttps://www.alibaba.com/product-detail/RF-star-ASR6505-433MHz-LoraWAN-LinkWAN_62502605557.html?spm=a2747.manage.0.0.5bc271d2cEMsVfhttps://www.alibaba.com/product-detail/Low-power-consumption-3000-meters-SX1278_62083932582.html?spm=a2747.manage.0.0.5bc271d2cEMsVfhttps://www.alibaba.com/product-detail/3000-meters-transmission-distance-SX1278-433MHz_62096776878.html?spm=a2747.manage.0.0.26dc71d285OxZPhttps://www.alibaba.com/product-detail/RF-star-ASR6501-433MHz-UART-Lora_62502967492.html?spm=a2747.manage.0.0.26dc71d285OxZPhttps://www.alibaba.com/product-detail/sx1276-915mhz-lora-module-RF-93UH_62100403512.html?spm=a2747.manage.0.0.26dc71d285OxZPhttps://www.alibaba.com/product-detail/Low-Power-High-Sensitivity-SX1276-862MHz_62099683304.html?spm=a2747.manage.0.0.26dc71d285OxZPhttps://www.alibaba.com/product-detail/Long-range-RF-module-Iot-915mhz_62101445001.html?spm=a2747.manage.0.0.26dc71d285OxZPhttps://www.alibaba.com/product-detail/Long-Range-RF-Module-Wireless-Transmitter_62101574820.html?spm=a2747.manage.0.0.26dc71d285OxZPhttps://www.alibaba.com/product-detail/8000-meters-long-distance-433MHz-410MHz_1600103549782.html?spm=a2747.manage.0.0.5bc271d2cEMsVf
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RF-42UH
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1 Device Overview
1.1 Description
RF-42UH module is a LoRa spread spectrum module, with operating frequency of 410 MHz ~ 525 MHz, based on the
Semtech SX1278. It is a wireless transceiver module with 3.3 V TTL level output. RF-star LoRa module features with
ultra-long range spread spectrum communication, concentrated power density, high interference immunity ability,
confidentiality, and significantly lower current consumption. The communication interface of RF-42UH is UART.
1.2 Key Features
• LoRaTM Modem
• 168 dB maximum link budget
• RF output power: +20 dBm
• +14 dBm high efficiency PA
• Programmable bit rate up to 300 kbps
• High sensitivity: down to -148 dBm
• Bullet-proof front end: IIP3 = -11 dBm
• Excellent blocking immunity
• Low RX current of 9.9 mA, 200 nA register retention
• Fully integrated synthesizer with a resolution of 61 Hz
• (G)FSK, (G)MSK, LoRaTM and OOK modulation
• Built-in bit synchronizer of clock recovery
• Preamble detection
• 127 dB Dynamic Range RSSI
• Automatic RF Sense and CAD with ultra-fast AFC
• Packet engine up to 256 bytes with CRC
• Built-in temperature sensor and low battery indicator
• Power supply: 3.3 V ~ 5.2 V
• Transmission distance: up to 3000 m
• Compact size: 26.0 mm x 16.0 mm
1.3 Applications
• Automated meter reading
• Home and building automation
• Wireless alarm and security systems
• Industrial monitoring and control
• Long range irrigation system
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1.4 Functional Block Diagram
Figure 1. Functional Block Diagram of RF-42UH
1.5 Part Number Conventions
The part numbers are of the form of RF-42UH where the fields are defined as follows:
Figure 2. Part Number Conventions of RF-42UH
RF 4
Company Name
RF-STAR
- 2
Communication Interface Mode
UART
TX Power
+20 dBm
U
Frequency Range
410 MHz ~ 525 MHz
H
Package Mode
Half-hole Package
32.0 MHz
MCU SX1278
SPI
Matching LPF
Matching
LDO
Switching
Low-pass Filter
Power Interface
Power Filter
Half-hole Interface
IPEX Connector Antenna
Switch
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Table of Contents
RF-star LoRa Module List ............................................................................................................................................... 1
1 Device Overview ............................................................................................................................................................. 2
1.1 Description ............................................................................................................................................................ 2
1.2 Key Features ....................................................................................................................................................... 2
1.3 Applications .......................................................................................................................................................... 2
1.4 Functional Block Diagram .............................................................................................................................. 3
1.5 Part Number Conventions .............................................................................................................................. 3
Table of Contents ................................................................................................................................................................ 4
Table of Figures ................................................................................................................................................................... 5
Table of Tables ..................................................................................................................................................................... 6
2 Module Configuration and Functions ...................................................................................................................... 7
2.1 Module Parameters ........................................................................................................................................... 7
2.2 Module Pin Diagram ......................................................................................................................................... 8
2.3 Pin Functions ....................................................................................................................................................... 8
3 Specifications ................................................................................................................................................................. 10
3.1 Recommended Operating Conditions ..................................................................................................... 10
3.2 Handling Ratings .............................................................................................................................................. 10
3.3 Current Consumption ..................................................................................................................................... 10
4 Application and Layout ............................................................................................................................................... 12
4.1 Module Photos .................................................................................................................................................. 12
4.2 Recommended PCB Footprint .................................................................................................................... 12
4.3 Schematic Diagram ......................................................................................................................................... 13
4.4 Reference Design of the Connection between MCU and Module ................................................ 13
5 Module Functions ......................................................................................................................................................... 14
5.1 Working Mode ................................................................................................................................................... 14
5.2 Mode Switching (0 for Low Level, 1 for High Level) ........................................................................... 14
5.3 Normal Mode ..................................................................................................................................................... 15
5.4 Wake-up Mode .................................................................................................................................................. 16
5.5 Low-power Mode ............................................................................................................................................. 16
5.6 Sleep Mode ........................................................................................................................................................ 16
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5.7 Data Security ..................................................................................................................................................... 17
6 Module Functions ......................................................................................................................................................... 18
6.1 Transparent Transmission ............................................................................................................................ 18
6.2 Fixed Point Transmission ............................................................................................................................. 18
6.3 Broadcast and Listening ............................................................................................................................... 19
6.4 Module Reset .................................................................................................................................................... 19
6.5 EN Function ....................................................................................................................................................... 20
7 Command Format......................................................................................................................................................... 22
7.1 AT Command ..................................................................................................................................................... 22
7.2 Parameters of Command Setting .............................................................................................................. 23
7.2.1 Format ..................................................................................................................................................... 23
7.2.2 Detailed Parameters .......................................................................................................................... 23
7.2.3 Examples ............................................................................................................................................... 26
8 Implementation .............................................................................................................................................................. 29
8.1 Hardware Design ............................................................................................................................................. 29
8.2 Trouble Shooting .............................................................................................................................................. 30
8.2.1 Unsatisfactory Transmission Distance ........................................................................................ 30
8.2.2 Vulnerable Module .............................................................................................................................. 30
8.2.3 High Bit Error Rate ............................................................................................................................. 30
8.3 Electrostatics Discharge Warnings ........................................................................................................... 30
8.4 Soldering and Reflow Condition ................................................................................................................. 31
8.5 Optional Packaging ......................................................................................................................................... 32
9 Revision History ............................................................................................................................................................ 33
10 Contact Us .................................................................................................................................................................... 34
Table of Figures
Figure 1. Functional Block Diagram of RF-42UH ......................................................................................... 3
Figure 2. Part Number Conventions of RF-42UH ......................................................................................... 3
Figure 3. Pin Diagram of RF-42UH .................................................................................................................... 8
Figure 4. Photos of RF-42UH ............................................................................................................................. 12
Figure 5. Recommended PCB Footprint of RF-42UH (mm) ................................................................... 12
Figure 6. Schematic Diagram of RF-42UH ................................................................................................... 13
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Figure 7. Reference Design of the Connection between MCU and Module .................................... 13
Figure 8. Transparent Transmission Function Diagram ........................................................................... 18
Figure 9. Point Transmission Function Diagram ......................................................................................... 19
Figure 10. EN Timing Diagram of Wake-up Sleep MCU .......................................................................... 20
Figure 11. EN Timing Diagram during Sending Data ................................................................................ 20
Figure 12. EN Timing Diagram during Receiving Data ............................................................................. 21
Figure 13. EN Timing Diagram during Setting Data................................................................................... 21
Figure 14. Recommended Reflow for Lead Free Solder ......................................................................... 32
Figure 15. Optional Packaging Mode .............................................................................................................. 32
Table of Tables
Table 1. Parameters of RF-42UH ........................................................................................................................ 7
Table 2. Pin Functions of RF-42UH .................................................................................................................... 8
Table 3. Recommended Operating Conditions of RF-42UH .................................................................. 10
Table 4. Handling Ratings of RF-42UH........................................................................................................... 10
Table 5. Current Consumption of RF-42UH .................................................................................................. 10
Table 6. Temperature Table of Soldering and Reflow ................................................................................ 31
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2 Module Configuration and Functions
2.1 Module Parameters
Table 1. Parameters of RF-42UH
Chipset Semtech SX1278
Supply Power Voltage 3.3 V ~ 5.2 V, recommended to 5.0 V
UART Communication Level 2.5 V ~ 3.6 V, typical: 3.3 V
Frequency 410 MHz ~ 525 MHz, typical: 433 MHz
Transmit Power +10.0 dBm ~ +20.0 dBm
Receiving Sensitivity -148 dBm
Number of Channels 116
Default Channel 23 (433 MHz)
Module Address Number 65538 (default as 0)
Crystal 32 MHz
Package SMT Packaging
Dimension 26.0 mm x 16.0 mm x (2.5 ± 0.1) mm
Antenna Half-hole interface / IPEX connector
Operating Humidity 10% RH ~ 90% RH (no condensation)
Storage Humidity 10% RH ~ 90% RH (no condensation)
Operating Temperature -40 ℃ ~ +85 ℃
Storage Temperature -45 ℃ ~ +90 ℃
Data Interface Rate @ 3.3 V (TTL) 1200 bps ~ 115200 bps, typical: 9600 bps
Air Rate 0.3 kbps ~ 19.2 kbps (typical: 2.4 kbps)
Single Package Size 196 byte
Cache Size 512 byte
Transmission Distance 3000 m (Test conditions: sunny weather, empty, +20 dBm, antenna gain of
5 dBi, height of above 2.5 m, air speed of 2.4 kbps)
Operating
Current @ 5 V
Tx Current 101 mA
Rx Current 15 mA
Sleep Current 3.4 μA
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2.2 Module Pin Diagram
Figure 3. Pin Diagram of RF-42UH
2.3 Pin Functions
Table 2. Pin Functions of RF-42UH
Pin Name Pin Type Description
1 GND - Ground
2 S0 I
Cooperate with S1 to determine the working mode.
(Cannot be NC, need be grounded if not used.)
3 S1 I
Cooperate with S0 to determine the working mode.
(Cannot be NC, need be grounded if not used.)
4 RXD I UART RX signal
5 TXD O UART TX signal
6 EN O
Pull the serial port high before sending data and pull low after sending.
Timed wake-up pin, pull high when wake-up.
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Pull high when module sending data, pull low after sending.
7 VCC - Power supply: 3.3 V ~ 5.2 V.
8 GND - Ground
9 RES_MCU I Reset pin, NC.
10 GND - Ground, NC.
11 3V3_MCU I/O VCC (Power supply pin when flash the firmware)
12 SWIM_MCU I/O SWIM pin of internal MCU
13 PB0 I/O NC
14 PB1 I/O NC
15 PB3 I/O NC
16 GND - Ground
17 GND - Ground
18 ANT I/O Antenna port
19 GND - Ground
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3 Specifications
3.1 Recommended Operating Conditions
Functional operation does not guarantee performance beyond the limits of the conditional parameter values in the table
below. Long-term work beyond this limit will affect the reliability of the module more or less.
Table 3. Recommended Operating Conditions of RF-42UH
Items Condition Min. Typ. Max. Unit
Operating Supply Voltage Battery Mode 3.3 5.0 5.2 V
Operating Temperature / -40 +25 +85 ℃
3.2 Handling Ratings
Table 4. Handling Ratings of RF-42UH
Items Condition Min. Typ. Max. Unit
Storage Temperature Tstg -45 +25 +90 ℃
Human Body Model HBM, class2 2000 4000 V
Moisture Sensitivity Level 2
Charged Device Model Class 3 500 1000 V
3.3 Current Consumption
The current consumption characteristics of this module are categorized into different running modes. The overall product
level current consumption is averaged over time on different power modes the device runs on. The peripheral circuitry’s
current consumption also adds in.
Table 5. Current Consumption of RF-42UH
Symbol Description Conditions Min. Typ. Max. Unit
IDDSL Supply current in Sleep mode 0.2 1 A
IDDIDLE Supply current in Idle mode RC oscillator enabled 1.5 A
IDDST Supply current in Standby mode Crystal oscillator enabled 1.6 1.8 mA
IDDFS Supply current in Synthesizer mode FSRx 5.8 mA
IDDR Supply current in Receive mode
LnaBoost Off, band 1 10.8 mA
LnaBoost On, band 1 11.5 mA
Bands 2 & 3 12.0 mA
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IDDT Supply current in Transmit mode with
impedance matching
RFOP = +20 dBm, on
PA_BOOST 120 mA
RFOP = +17 dBm, on
PA_BOOST 87 mA
RFOP = +13 dBm, on
RFO_LF/HF pin 29 mA
RFOP = +7 dBm, on
RFO_LF/HF pin 20 mA
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4 Application and Layout
4.1 Module Photos
Figure 4. Photos of RF-42UH
4.2 Recommended PCB Footprint
Figure 5. Recommended PCB Footprint of RF-42UH (mm)
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4.3 Schematic Diagram
Figure 6. Schematic Diagram of RF-42UH
4.4 Reference Design of the Connection between MCU and Module
Figure 7. Reference Design of the Connection between MCU and Module
Note: TTL level for module and MCU.
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5 Module Functions
5.1 Working Mode
RF-42UH supports 4 kinds of working modes.
Working Mode S0 S1 Mode Description Remark
Normal mode Low level Low level Transparent transmission mode.
The receiver must work in
normal mode or wake-up
mode.
Wake-up mode Low level High level
Difference from the normal mode:
Before data packet transmission,
automatically add a wake-up code to
wake up the receiver module working
in low-power mode.
The receiver can be in
normal mode, wake-up
mode and low-power mode.
Low-power
mode High level Low level
Serial port reception is off, and it is in
the air waiting for wake-up mode.
After receiving wireless data, open the
serial port to send data.
The transmitter must work in
the wake-up mode.
Unable to transmit data in
low-power mode.
Sleep mode High level High level Unable to transmit data, only can
modify and query parameters.
Modify and query settings
and sleep.
Note: Parameters can be modified and queried in all modes. Modification of parameters requires a power-on reset of
the module to take effect. Modifications in sleep mode can be used directly.
5.2 Mode Switching (0 for Low Level, 1 for High Level)
1. Combine high and low levels of S0 and S1 to determine the working mode of the module. Two GPIOs of MCU can
be used to control mode switching. When the level of S0 and S1 are changed, the module is idle for 1 ms, that is,
it starts to work according to the new mode. If the module has serial port data that has not been transmitted by
wireless, it can enter the new working mode after the transmission is completed. If the module receives wireless
data and sends out data through the serial port, it needs to finish sending before entering the new working mod.
Therefore, the mode switching can only be effective when EN outputs 1, otherwise it will delay the switching. For
example: in normal mode or wake-up mode, the user continuously inputs a large amount of data and switches the
mode at the same time. At this time, the mode switching operation is invalid, and the module will process all user
data before performing new mode detection. So, it is generally recommended to detect the output state of the EN
pin and wait for 2 ms after the EN output is high before switching.
2. When the module is switched from other modes to sleep mode, if there is any data that has not been processed
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yet, the module will enter the sleep mode after processing these data (including receiving and sending). This feature
can be used for fast sleep, thus saving power consumption. For example: the transmitter module works in normal
mode, the user initiates serial data "ABC", and then does not have to wait for the EN pin to be idle (high level), and
it can directly switch to sleep mode and the main MCU will immediately sleep. The module will automatically send
all user data by wireless, and then automatically enter sleep within 1 ms, thus saving the working time of MCU and
reducing power consumption.
3. This feature can be used for all mode switching. After processing the current mode event, the module will
automatically enter the new mode within 1 ms, thus eliminating the user's work of querying EN and achieving the
purpose of fast switching. For example: switching from transmit mode to receive mode, the user MCU can also go
to sleep in advance before the mode switching, and use the external interrupt function to get the EN change for
mode switching. This operation method is flexible and efficient, and is designed in accordance with the convenience
of the user MCU, and can reduce the workload of the entire system as much as possible, improve system efficiency,
and reduce power consumption.
5.3 Normal Mode
Type When S0 = 0 and S1 = 0, the module works in normal mode.
Transmitting
The single packet length of wireless data transmitted by the module is 196 bytes. When the amount
of data input by the user reaches 196 bytes, the module will start wireless transmission. At this time,
the user can continue to input the data to be transmitted. When the byte to be transmitted by the
user is less than 196 bytes, the module waits for 3 bytes. If no user data continues to be input, the
data is considered to be terminated. At this time, the module will send all the data packets by
wireless. When the module receives the first user data, it outputs the EN to the low level, when the
module puts all the data into the RF chip and starts the transmission, the EN outputs to the high
level. At this time, it indicates that the last packet of wireless data has started the transmission, and
the user can continue to input up to 512 bytes of data. The packets sent out through the normal
mode can only be received by the receiving module in normal mode and wake-up mode.
Receiving
The module always turns on the wireless receiving function, and can receive the data packets sent
from the normal mode and wake-up mode. After receiving the data packets, the module EN outputs
the low level and delays for 5 ms, and It starts to send the wireless data through the serial port TXD
pin. After all the wireless data are output through the serial port, the module outputs the EN to the
high level.
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5.4 Wake-up Mode
Type When S0 = 0 and S1 = 1, the module works in wake-up mode.
Transmitting
The conditions for the module to start packet transmission and the EN function are the same as the
EN function. The only difference is that the module will automatically add a wake-up code before
each packet. The length of the wake-up code depends on the wake-up time set in the user
parameters. The purpose of the wake-up code is to wake up the receiving module working in the
low power consumption mode. Therefore, the data transmitted in the wake-up mode can be used in
the normal mode Module received in wake-up mode and low power consumption mode.
The conditions under which the module initiates a packet transmission and the EN functions are
equivalent to normal mode. The only difference is that the module automatically adds a wake-up
code before each data packet, and the length of the wake-up code depends on the wake-up time
set in the user parameters. The purpose of the wake-up code is to wake up the receiving module
working in the low-power mode. Therefore, the data transmitted in the wake-up mode can be
received by the module in the normal mode, wake-up mode, and low-power mode.
Receiving Equivalent to normal mode.
5.5 Low-power Mode
Type When S0 = 1 and S1 = 0, the module works in low-power mode
Transmitting The module is in sleep state, the serial port is closed, and it cannot receive the serial port data from
the external MCU, so this mode does not have the function of wireless transmission.
Receiving
In the low-power mode, the transmitter is required to work in the wake-up mode. When the wake-
up code is monitored regularly, once the effective wake-up code is received, the module will continue
to be in the receiving state and wait for the whole effective packet to be received. Then the EN
outputs the low Level, after a delay of 5 ms, open the serial port to send the wireless data received
through TXD, and the EN outputs the high when finished. The wireless module continues to enter
the "sleep-monitor" working state, by setting different wake-up time, the module has different receive
response delay (maximum 2 s) and average power consumption (minimum 30 A).
5.6 Sleep Mode
Type When S0 = 1 and S1 = 1, the module works in sleep mode
Transmitting Unable to transmit.
Receiving Unable to receive.
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Configuration
The sleep mode can be used for module parameter setting. Use serial ports 9600 and 8N1 to set
the module working parameters through a specific instruction format, as shown in the following
instruction format details. When entering other modes from sleep mode, the module will re-configure
the parameters. During the configuration, EN remains low. After completion, the module outputs
high level, so it is recommended that users detect the rising edge of EN.
5.7 Data Security
The specific encryption algorithm is used to encrypt the module data. After receiving the data, the receiving module can
get the actual transmission data according to the encryption factor to avoid receiving the wrong information.
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6 Module Functions
6.1 Transparent Transmission
The transparent data transmission under the same channel, the same module address and the same airspeed is shown
in the figure below.
Figure 8. Transparent Transmission Function Diagram
6.2 Fixed Point Transmission
The transparent data transmission under the different channel, the different module address and the different airspeed
is shown in the figure below.
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Figure 9. Point Transmission Function Diagram
6.3 Broadcast and Listening
Input the broadcast address FF FF, the channel XX, and the data to be transmitted in proper order, and then send. All
modules on channel XX within the range of the wireless signal can receive the broadcast data, that is, co-channel
broadcast. However, the address and channel of the sending module can be arbitrary and are not required. The
requirement is to input the broadcast address and destination channel.
Listening and broadcasting are exactly the opposite. Listening is passive. Set the address of the module itself to FF FF,
and the module can receive the data sent by all modules on channel XX.
Note: Broadcast address and listening address are only FF FF.
6.4 Module Reset
After the module is powered on, EN will output low level immediately, carry out hardware self-check, and set the working
mode according to the user parameters. In this process, the EN keeps the low level, and after that, the EN outputs the
high level, and starts to work normally according to the working mode composed of S1 and S0. Therefore, the user
needs to wait for the EN rising edge as the starting point for the normal operation of the module.
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6.5 EN Function
EN is used for wireless transceiver buffer indication and self-check indication. It indicates whether any data of the module
has not been transmitted through the wireless, whether the wireless data has been received but has not been completely
transmitted through the serial port, or the module is in the process of initial self-check.
1. Wake-up MCU
Figure 10. EN Timing Diagram of Wake-up Sleep MCU
2. Send indication
Figure 11. EN Timing Diagram during Sending Data
3. Receive indication
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Figure 12. EN Timing Diagram during Receiving Data
4. Configuration process
Figure 13. EN Timing Diagram during Setting Data
5. Cautions
⚫ EN outputting low level takes priority. When any low-level output condition is met, EN outputs low level. When all
low-level conditions are not met, EN outputs high level.
⚫ When the EN output in at low level, it means that the module is busy, and the working mode detection will not be
carried out at this time. When the module EN output is at high level, it means the mode switching will be completed
within 1 ms.
⚫ After switching to the new working mode, the module will enter the mode at least 2 ms after the rising edge of EN.
When the EN output is always at high level, the mode switching will take effect immediately.
⚫ When entering from sleep mode to other modes or during reset, the module will reset the parameters, during which
EN output is low.
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7 Command Format
7.1 AT Command
The supported instruction list is as follows (all operations of the module are conducted at the current baud rate in normal
mode, wake-up mode, and sleep mode):
No. Command Format Description
1 AT_READ
Send "AT_READ" in ASCII format, the module returns the saved parameters.
For example: "AT_READ=00,31,1A,3C,40".
Supports the operation in normal mode, wake-up mode, and sleep mode.
2 AT_VER
Send "AT_VER" in ASCII format, the module will return the version number.
For example: "AT_VER=A3,01,10,14".
Supports normal mode, wake-up mode, and sleep mode.
3 AT_RSSI
Send "AT_RSSI" in ASCII format, the module returns "AT_RSSI=value (hex)".
For example: "AT_RSSI = 2F".
Supports the operation in normal mode, wake-up mode, and sleep mode.
4 “AT_SET=”
+ working parameters
Send “AT_SET=+ (5 bytes working parameters)” in ASCII format, and the
parameters are saved after power off.
For example: "AT_SET=00,31,1A,3C,40".
Supports the operation in normal mode, wake-up mode, and sleep mode.
5 “AT_USET=”
+ working parameters
Send “AT_USET=+ (5 bytes working parameters)” in ASCII format, and the
parameters are not be saved after power off.
For example: "AT_USET = 00,31,1A, 3C, 40".
Supports the operation in normal mode, wake-up mode, and sleep mode.
Note: Send AT_RSSI, return AT_RSSI=xx. Below the band of 525 MHz: Value = -157 + xx. Above the band of 779 MHz:
Value = -164 + xx.
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7.2 Parameters of Command Setting
7.2.1 Format
There are five groups in total, two bytes in each group, and 8 bits in each group.
For example: AT_SET=00,01,1A,3C,40
In normal mode, wake-up mode or sleep mode, you can directly input " AT_SET=00,01,1A,3C,40" in the serial port
assistant command box in ASCII, and press send button to get the module response. If the input is correct, the data just
entered will be returned.
7.2.2 Detailed Parameters
1. The first group of data represents the type of control command.
AT_SET represents the control command type, which is fixed to AT_SET and AT_USET.
AT_SET represents that the set parameters are saved after power off.
AT_USET represents that the set parameters are not saved after power failure.
2. The second group of data represents the module address.
By default [00 00], the module address range is 0 ~ 65535, and in Hex [00 00] ~ [FF FF]
3. The third group of data represents: serial parity bit, serial baud rate, and air rate of wireless signal.
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The specific understanding is as follows: [1A] is in hex, and its binary is [0001 1010].
bit7, bit6 means serial parity bit
bit7 bit6 Serial Parity BIt Description
0 0 8N1 (by default)
The serial port mode of communication module can be
different.
0 1 8O1
1 0 8E1
1 1 8N1 (Equivalent to 00)
bit5, bit4, bit3 means baud rate.
bit5 bit4 bit3 Baud Rate (bps) Description
0 0 0 1200
The baud rate of both sides of communication
module can be different. The baud rate of the serial
port is independent of the wireless transmission
parameters and does not affect the characteristics of
the wireless transceiver.
0 0 1 2400
0 1 0 4800
0 1 1 9600 (by default)
1 0 0 19200
1 0 1 38400
1 1 0 57600
1 1 1 115200
bit3, bit2, bit1 means air rate.
bit3 bit2 bit1 Air Rate (bps) Description
0 0 0 0.3k
The lower the air rate, the longer the distance. The
stronger the anti-interference performance and the
longer the transmission time.
The air rate of both sides must be the same.
0 0 1 1.2k
0 1 0 2.4k (by default)
0 1 1 4.8k
1 0 0 9.6k
1 0 1 19.2k
1 1 0 19.2k (Equivalent to 101)
1 1 1 19.2k (Equivalent to 101)
In summary, the parameters of [1A] (in hex) → [0001 1010] (in binary) are: [8N1, baud rate: 9600, air rate of 2.4k].
For example: The parameters needed are the module address of 1000 (in decimal), the serial parity bit of 8N1, the baud
rate of 19200, and air rate 19.2k. Expressed as:
⚫ Address is 1000 in decimal, and the hexadecimal representation is 0x03E8, express it as [03 E8].
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⚫ Serial parity bit is 8N1, and the binary representation is [00].
⚫ Baud rate is 19200, and the binary representation is [100]
⚫ Air rate is 19.2k, and the binary representation is [101]
All in all, it is [0010 0101], and converted to hexadecimal is [25]. The first four commands can be expressed as: [AT_SET
= 03,E8,25]
4. The fourth group of data represents the channel.
The channel range is 410 MHz ~ 525 MHz with 1 M interval. Channel 23 in decimal is [17] in hex, corresponding to
(410+ channels) MHz = 433 MHz. Channel 60 in decimal is [3C] in hex, corresponding to (410+ channels) MHz = 470
MHz.
The first five commands can be expressed as: [AT_SET = A0,03,E8,25,17]
5. The fifth group of data represents: transmission mode, IO driving method, wireless wake-up time, transmit
power.
The specific understanding is as follows: [40] is a hexadecimal representation, it needed to be converted to a binary
representation, that is, [0100 0000].
bit7 indicates the transmission mode
bit7 Transmission Mode Description
0 Transparent transmission When it is 1, the first three bytes of each user's data frame are used as
high, low address and channel. When transmitting, the module changes
its address and channel, and then restores the original settings after
completed.
1 Fixed point transmission
bit6 indicates the IO driven mode
bit6 IO Driven Mode (default as 1) Description
0 TXD, EN open circuit output,
RXD open circuit input This bit is used to enable the internal pull-up resistor of the module.
Open-drain mode has stronger level adaptability. In some cases, an
external pull-up resistor may be required. 1 TXD, EN push-pull output, RXD
pull-up input
bit5, bit4 and bit3 indicates the wireless wake-up time
bit3 bit2 bit1 Wake-up Time (ms) Description
0 0 0 250 (by default) The transceiver modules work in normal mode. The delay time is invalid
and can be any value. 0 0 1 500
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0 1 0 750 The transmitting module works in the wake-up mode and will
continuously transmit the call code for the corresponding time.
The receiving module works in low-power mode. This time refers to the
listening interval time (wireless wake-up) of the receiver and can only
receive data from the transmitting module working in wake-up mode.
0 1 1 1000
1 0 0 1250
1 0 1 1500
1 1 0 1750
1 1 1 2000
bit2 is reserved unused.
bit1 and bit0 indicate the transmit power.
bit1 bit0 Transmit Power
(Approximate Value) Description
0 0 20 dBm (by default) The external power supply must provide more than 250 mA current
output capability. And ensure that the power supply ripple is less than
100 mV. It is not recommended to use smaller power transmission,
because its power utilization efficiency is not high.
0 1 17 dBm
1 0 14 dBm
1 1 10 dBm
7.2.3 Examples
Examples: 1. Normal mode, 2. Push-pull output, 3. Wireless wake-up time of 500 ms, 4. Transmit power of 20 dBm. It
needs to be expressed as follows: (bit 2 is reserved unused and default as 0)
[1 001 0 00], converted to hexadecimal = [48]
The above can be expressed as: [AT_SET=03,E8,25,17,48]. What it means: All set parameters are saved after powered
off. The parameters are modified to: module address of 1000, serial parity bit of 8N1, baud rate of 19200, air rate of
19.2k, channel of 23 (frequency 433), normal mode, push-pull output, wake-up time of 500 ms and transmit power of 20
dBm.
Here are some common commands:
1. The second group of data: address
Address Number In Hex
Address 1 00 01
Address 2 00 02
Address 3 00 03
Address 30 00 1E
Address 31 00 1F
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Address 32 00 20
Address 60 00 3C
Address 61 00 3D
Address 62 00 3E
Address 101 00 65
Address 102 00 66
Address 103 00 67
2. The third group of data: serial parity bit, baud rate, air rate
Serial Parity Bite Baud Rate (bps) Air Rate (bps) In Binary In Hex
8N1 9600 0.3k 00 011 000 18
8N1 9600 2.4k 00 011 010 1A
8N1 9600 19.2k 00 011 101 1D
8N1 19200 0.3k 00 100 000 20
8N1 19200 2.4k 00 100 010 22
8N1 19200 19.2k 00 100 101 25
8N1 115200 0.3k 00 111 000 38
8N1 115200 2.4k 00 111 010 3A
8N1 115200 19.2k 00 111 101 3D
8O1 9600 0.3k 01 011 000 58
8O1 9600 2.4k 01 011 010 5A
8O1 9600 19.2k 01 011 101 5D
8O1 115200 0.3k 01 111 000 78
8O1 115200 2.4k 01 111 010 7A
8O1 115200 19.2k 01 111 101 7D
3. The fourth group of data: channel
Interval: 1M. 116 channels in total.
Channel Number Frequency (MHz) In Hex
1 410 01
10 420 0A
20 440 14
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23 433 17
40 450 28
60 470 3C
80 490 50
4. The fifth group of data: transmission mode, IO driving method, wireless wake-up time, transmit power (bit2
is not used and default as 0)
Transmission Mode IO Driven Mode Wake-up Time
(ms)
Transmit Power
(dBm) In Binary In Hex
Transparent transmission Open circuit output 250 20 0 0 000 0 00 00
Transparent transmission Open circuit output 1000 20 0 0 011 0 00 18
Transparent transmission Open circuit output 2000 20 0 0 111 0 00 38
Transparent transmission Push-pull output 250 20 0 1 000 0 00 40
Transparent transmission Push-pull output 1000 20 0 1 011 0 00 58
Transparent transmission Push-pull output 1500 20 0 1 101 0 00 68
Transparent transmission Push-pull output 2000 20 0 1 111 0 00 78
Fixed point transmission Open circuit output 250 20 1 0 000 0 00 80
Fixed point transmission Open circuit output 1000 20 1 0 011 0 00 98
Fixed point transmission Open circuit output 1500 20 1 0 101 0 00 A8
Fixed point transmission Push-pull output 2000 20 1 1 111 0 00 F8
Fixed point transmission Push-pull output 250 20 1 1 000 0 00 C0
Fixed point transmission Push-pull output 1000 20 1 1 011 0 00 D8
Fixed point transmission Push-pull output 2000 20 1 1 111 0 00 F8
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8 Implementation
8.1 Hardware Design
1. It is recommended to offer the module with a DC stabilized power supply, a tiny power supply ripple coefficient and
the reliable ground. Please pay attention to the correct connection between the positive and negative poles of the
power supply. Otherwise, the reverse connection may cause permanent damage to the module;
2. Please ensure the supply voltage is between the recommended values. The module will be permanently damaged
if the voltage exceeds the maximum value. Please ensure the stable power supply and no frequently fluctuated
voltage.
3. When designing the power supply circuit for the module, it is recommended to reserve more than 30% of the margin,
which is beneficial to the long-term stable operation of the whole machine. The module should be far away from the
power electromagnetic, transformer, high-frequency wiring and other parts with large electromagnetic interference.
4. The bottom of module should avoid high-frequency digital routing, high-frequency analog routing and power routing.
If it has to route the wire on the bottom of module, for example, it is assumed that the module is soldered to the Top
Layer, the copper must be spread on the connection part of the top layer and the module, and be close to the digital
part of module and routed in the Bottom Layer (all copper is well grounded).
5. Assuming that the module is soldered or placed in the Top Layer, it is also wrong to randomly route the Bottom Layer
or other layers, which will affect the spurs and receiving sensitivity of the module to some degrees;
6. Assuming that there are devices with large electromagnetic interference around the module, which will greatly affect
the module performance. It is recommended to stay away from the module according to the strength of the
interference. If circumstances permit, appropriate isolation and shielding can be done.
7. Assuming that there are routings of large electromagnetic interference around the module (high-frequency digital,
high-frequency analog, power routings), which will also greatly affect the module performance. It is recommended
to stay away from the module according to the strength of the interference. If circumstances permit, appropriate
isolation and shielding can be done.
8. It is recommended to stay away from the devices whose TTL protocol is the same 433 MHz physical layer, for
example: USB 3.0.
9. The antenna installation structure has a great influence on the module performance. It is necessary to ensure the
antenna is exposed and preferably vertically upward. When the module is installed inside of the case, a high-quality
antenna extension wire can be used to extend the antenna to the outside of the case.
10. The antenna must not be installed inside the metal case, which will cause the transmission distance to be greatly
weakened.
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8.2 Trouble Shooting
8.2.1 Unsatisfactory Transmission Distance
1. When there is a linear communication obstacle, the communication distance will be correspondingly weakened.
Temperature, humidity, and co-channel interference will lead to an increase in communication packet loss rate. The
performances of ground absorption and reflection of radio waves will be poor, when the module is tested close to
the ground.
2. Seawater has a strong ability to absorb radio waves, so the test results by seaside are poor.
3. The signal attenuation will be very obvious, if there is a metal near the antenna or the module is placed inside of the
metal shell.
4. The incorrect power register set or the high data rate in an open air may shorten the communication distance. The
higher the data rate, the closer the distance.
5. The low voltage of the power supply is lower than the recommended value at ambient temperature, and the lower
the voltage, the smaller the power is.
6. The unmatchable antennas and module or the poor quality of antenna will affect the communication distance.
8.2.2 Vulnerable Module
1. Please ensure the supply voltage is between the recommended values. The module will be permanently damaged
if the voltage exceeds the maximum value. Please ensure the stable power supply and no frequently fluctuated
voltage.
2. Please ensure the anti-static installation and the electrostatic sensitivity of high-frequency devices.
3. Due to some humidity sensitive components, please ensure the suitable humidity during installation and application.
If there is no special demand, it is not recommended to use at too high or too low temperature.
8.2.3 High Bit Error Rate
1. There are co-channel signal interferences nearby. It is recommended to be away from the interference sources or
modify the frequency and channel to avoid interferences.
2. The clock waveform on SPI is not standard. Check whether there is interference on the SPI line. The SPI bus line
should not be too long.
3. The unsatisfactory power supply may also cause garbled. It is necessary to ensure the power supply reliability.
4. If the extension wire or feeder wire is of poor quality or too long, the bit error rate will be high.
8.3 Electrostatics Discharge Warnings
The module will be damaged for the discharge of static. RF-star suggest that all modules should follow the 3 precautions
below:
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1. According to the anti-static measures, bare hands are not allowed to touch modules.
2. Modules must be placed in anti- static areas.
3. Take the anti-static circuitry (when inputting HV or VHF) into consideration in product design.
Static may result in the degradation in performance of module, even causing the failure.
8.4 Soldering and Reflow Condition
1. Heating method: Conventional Convection or IR/convection.
2. Solder paste composition: Sn96.5 / Ag3.0 / Cu0.5
3. Allowable reflow soldering times: 2 times based on the following reflow soldering profile.
4. Temperature profile: Reflow soldering shall be done according to the following temperature profile.
5. Peak temperature: 245 ℃.
Table 6. Temperature Table of Soldering and Reflow
Profile Feature Sn-Pb Assembly Pb-Free Assembly
Solder Paste Sn63 / Pb37 Sn96.5 / Ag3.0 / Cu0.5
Min. Preheating Temperature (Tmin) 100 ℃ 150 ℃
Max. Preheating Temperature (Tmax) 150 ℃ 200 ℃
Preheating Time (Tmin to Tmax) (t1) 60 s ~ 120 s 60 s ~ 120 s
Average Ascend Rate (Tmax to Tp) Max. 3 ℃/s Max. 3 ℃/s
Liquid Temperature (TL) 183 ℃ 217 ℃
Time above Liquidus (tL) 60 s ~ 90 s 30 s ~ 90 s
Peak Temperature (Tp) 220 ℃ ~ 235 ℃ 230 ℃ ~ 250 ℃
Average Descend Rate (Tp to Tmax) Max. 6 ℃/s Max. 6 ℃/s
Time from 25 ℃ to Peak Temperature (t2) Max. 6 minutes Max. 8 minutes
Time of Soldering Zone (tP) 20±10 s 20±10 s
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Figure 14. Recommended Reflow for Lead Free Solder
8.5 Optional Packaging
Figure 15. Optional Packaging Mode
Note: Default tray packaging.
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9 Revision History
Date Version No. Description Author
2018.12.28 V0.9 The initial version is released. Aroo Wang
2019.01.27 V1.0 Update module picture. Aroo Wang
2019.03.06 V1.1 Add part number conventions. Aroo Wang
2019.06.05 V1.2 Add the Chapter of Application, Implementation, and
Layout Aroo Wang
2019.06.19 V1.3 Update the description. Aroo Wang
2020.01.19 V1.3 Add LoRa module list. Sunny Li
Note:
1. The document will be optimized and updated from time to time. Before using this document, please make sure it is
the latest version.
2. To obtain the latest document, please download it from the official website: www.szrfstar.com.
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10 Contact Us
SHENZHEN RF-STAR TECHNOLOGY CO., LTD.
Shenzhen HQ:
Add.: Room 601, Block C, Skyworth Building, High-tech Park, Nanshan District, Shenzhen, Guangdong, China
Tel.: 86-755-3695 3756
Chengdu Branch:
Add.: No. B3-03, Building No.1, Incubation Park, High-Tech District, Chengdu, Sichuan, China, 610000
Tel.: 86-28-6577 5970
Email: [email protected], [email protected]
Web.: www.szrfstar.com
http://www.szrfstar.com/mailto:[email protected]://www.szrfstar.com/
RF-star LoRa Module List1 Device Overview1.1 Description1.2 Key Features1.3 Applications1.4 Functional Block Diagram1.5 Part Number Conventions
Table of ContentsTable of FiguresTable of Tables2 Module Configuration and Functions2.1 Module Parameters2.2 Module Pin Diagram2.3 Pin Functions
3 Specifications3.1 Recommended Operating Conditions3.2 Handling Ratings3.3 Current Consumption
4 Application and Layout4.1 Module Photos4.2 Recommended PCB Footprint4.3 Schematic Diagram4.4 Reference Design of the Connection between MCU and Module
5 Module Functions5.1 Working Mode5.2 Mode Switching (0 for Low Level, 1 for High Level)5.3 Normal Mode5.4 Wake-up Mode5.5 Low-power Mode5.6 Sleep Mode5.7 Data Security
6 Module Functions6.1 Transparent Transmission6.2 Fixed Point Transmission6.3 Broadcast and Listening6.4 Module Reset6.5 EN Function
7 Command Format7.1 AT Command7.2 Parameters of Command Setting7.2.1 Format7.2.2 Detailed Parameters7.2.3 Examples
8 Implementation8.1 Hardware Design8.2 Trouble Shooting8.2.1 Unsatisfactory Transmission Distance8.2.2 Vulnerable Module8.2.3 High Bit Error Rate
8.3 Electrostatics Discharge Warnings8.4 Soldering and Reflow Condition8.5 Optional Packaging
9 Revision History10 Contact Us