EBYTE EWM32M-xxxT20S AT Directive 20dBm Small Form Factor LoRa Wireless Module

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Introduction

Brief Introduction
EWM32M-xxxT20S series (UART) is an ultra-small size, low-cost wireless serial module (UART), and the E32 is fully compatible with the interoperability of the LORA communication technology, its transmit power of 20dBm, with a variety of transmission modes, working in the 433-band and the 900-band, TTL level output, compatible with the 3.3V IO port voltage.
EWM32M-xxxT20S has the advantages of longer communication distance, strong anti-interference ability, and strong confidentiality. The factory default air rate is 2.4kbps, and the transmit power is 20dBm, which improves the communication stability and extends the communication distance; the two modules in the figure below have the same power and different frequency bands.

 Features

• Adopts the new generation of LoRa spread spectrum modulation technology, which brings longer communication distance and stronger anti-interference ability;
• Supports serial port to upgrade firmware, which makes updating firmware more convenient;
• Supports AT command, which is more convenient to use;
• Supports FEC forward error correction, improving communication stability;
• Supports global license-free ISM 433MHz band or 868/915MHz EU common band;
• Supports users to set their own communication key and it cannot be read, which greatly improves the confidentiality of user data;
• Supports LBT function to listen to the channel environmental noise before sending, which can greatly improve the success rate of the module’s communication in harsh environments;
• Supports wireless parameter configuration, sending command packets wirelessly to remotely configure or read wireless module parameters;
• Supports Wake-on-Air, i.e., ultra-low power consumption function for battery-powered application solutions;
• Supports fixed-point transmission, broadcast transmission, and channel listening;
• Supports deep hibernation, the whole power consumption in this mode is about 3uA;
• Communication distance is up to 5km under ideal conditions;
• Parameters are saved when power down, and the module will work according to the set parameters after power up again;
• High-efficiency watchdog design, once an exception occurs, the module will be in automatic restart, and can continue to continue to work in accordance with the previous parameter settings;
• Supports data transfer rate of 2.4K to 19.2Kbps;
• Supports 2.7~5.5V power supply, and any power supply greater than 5V can ensure the best performance;
• Industrial-grade standard design, support -40 ~ +85 ℃ for long time use;
• Module power can be up to 100mW (20dBm), transmission farther and more stable.

Application

• Home security alarms and remote keyless entry;
• Smart home as well as industrial sensors and more;
• Wireless alarm security systems;
• Building automation solutions;
• Wireless industrial grade remote controls;
• Healthcare products;
• Advanced Meter Reading Architecture (AMI).

Specification

RF parameters 

RF parameters	unit	Performances			Remark
		Minimum value	Typical value	Maximum values
Maximum Transmit Power	dBm	–	20	–	–
Receiving Sensitivity	dBm	123	124	125	Air rate of 2.4kbps
Reference Distance	M	–	5K	–	Clear and open, antenna gain 5dBi, antenna height 2.5 meters, air rate 2.4kbps.
Operating Frequency Band	MHz	410	433	441	Applicable to EWM32M-433T20S.
	MHz	862	900	930	Applicable to EWM32M-900T20S.
Air Rate	bps	2.4K	2.4K	19.2K	User programmable control
Blocking power	dBm	–	-10	–	Less probability of burnout in close proximity

Electrical parameters

Electrical parameters		UNI T	model number		Remark
			EWM32M- 433T20S	EWM32M- 900T20S
operating voltage		V	2.7～5.5	2.7～5.5	Output power is guaranteed at ≥3.3V, 5V typical, above 5.5V permanently burns out the module.
communications level		V	3.3V	3.3V	Risk of burn-in using 5V TTL
power consump tion	Transmit Current	mA	110	Transient power consumption @22dBm	Instantaneous power consumption @22dBm
	Receive Current	mA	8
	Sleep Current	uA	3	Software shutdown	Software shutdown
operating temperature		℃	-40～+85		Industrial Grade Design

Hardware parameters

Hardware parameters	Model Nnumber		Remark
	EWM32M-433T20S	EWM32M-900T20S
Modulation mode	LoRa		New generation of LoRa modulation technology
Interface Mode	1.27mm stamp hole
Communicat ion Interface	UART serial port		TTL level
Transmit length	58 Btye		Maximum capacity of a single package, automatically divided into packages after exceeding it
Package	SMD		–
Cache Capacity	512Btye		–
Antenna	IPEX-1/Stamp Hole		Equivalent impedance approx. 50Ω

Interface
Dimension	14*20mm	±0.2mm
Net Weight	2.0g	±0.1g

Mechanical Dimensions and Pin Definitions

EWM32M-433/900T20S Mechanical Dimensions and Pin Definitions

Pin No	Name	Pin Direction	Pin Usage
1	GND	–	Module Ground
2	NC	–	Empty pin (not open for use, no need for user concern)
3	GND	–	Module Ground
4	GND	–	Module Ground
5	TX_EN	Output	Used in conjunction with RX_EN to control external PA; left blank if not used

6	RX_EN	Output	Used in conjunction with TX_EN to control external PA; left blank if not used
7	CLK	Input/Output	SWCLK Clock pin for program loading (dangling, no need to be connected by the user)
8	DIO	Input/Output	SWDIO Data pin for program loading (dangling, no need to be connected by the user)
9	NC	–	Empty foot (not open for use, no need for users to care)
10	NC	–	Empty foot (not open for use, users do not need to care)
11	NC	–	Empty feet (not open for use, users do not need to care)
12	NC	–	Empty foot (not open to use, users do not need to care)
13	GND	–	Module Ground
14	VCC	–	Module power positive reference, voltage range: 2.7 to 5.5V DC
15	TXD	OUTPUT	TTL serial output, connected to external RXD output pin;
16	RXD	Input	TTL serial input, connected to external TXD output pin;
17	M1	Input	TTL serial input, connected to the external TXD output pin; and M0, determines the module’s four operating modes (can not be suspended, if not used can be grounded)
18	M0	Input	In conjunction with M1, determines the 4 modes of operation for the module (not dangling, can be grounded if not in use)
19	AUX	Output	Used to indicate the working status of the module; the user wakes up the external MCU and outputs a low level during power-on self-test initialization; (can be suspended)
20	NC	-Input	Empty pin (not open for use, no need for user to care)
21	RESET	Input	Module reset pin, low level reset.
22	GND	–	Module ground
23	ANT	–	Antenna interface (high frequency signal output, 50 ohm characteristic impedance)
24	GND	–	Module Ground

Recommended Connectivity Charts

 

Functions in detail

 Fired at a fixed point

 

Broadcast emission

• Broadcast address
  • Example: set module A address to 0xFFFF and channel to 0x04.
  • When module A is used as a transmitter (same mode, transparent transmission method), all receiving modules under channel 0x04 can receive the data for the purpose of broadcasting.
• Listening address
  • Example: set module A address to 0xFFFF and channel to 0x04.
  • When module A is used as a receive, it can receive all the data under channel 0x04 to achieve the purpose of listening.
• Module reset
  • After the module is powered on, AUX will immediately output a low level, and carry out hardware self-test, as well as set up the working mode according to user parameters; During this process, AUX will keep low level, and when finished, AUX will output high level, and start to work normally according to the working mode combined by M1 and M0; Therefore, the user needs to wait for the rising edge of AUX as the starting point of normal operation of the module.
• AUX in detail
  • AUX is used for wireless transceiver buffer indication and self-test indication.
  • It indicates whether the module has data that has not yet been transmitted out through the wireless, or whether the wireless data that has already been received has not yet been sent out in full through the serial port, or whether the module is in the process of initializing the self-test.
• Serial data output indication
  • is used for waking up an external MCU in hibernation;

Radio transmission indication

• Buffer Empty: the data in the internal 512 byte buffer are written to the wireless chip (automatic packetization).
• When AUX=1 when the user continuously initiates less than 512 bytes of data, will not overflow. When AUX=0 when the buffer is not empty: the internal 512-byte buffer data, not yet all written to the wireless chip and open the launch, at this time the module may be waiting for the end of the user’s data timeout, or are wireless sub-packet launch.
• [Note]: AUX=1 does not mean that all the serial data of the module have been launched through the wireless, or the last packet of data is being launched.

Module in the process of being configured

only when resetting and exiting hibernation mode; Caution

No	AUX Notes
1	For function 1 and function 2 above, the output low level is prioritized, i.e.: when any of the output low level conditions are satisfied, the AUX outputs a low level; When all low level conditions are not satisfied, AUX outputs high level.
2	When AUX outputs low level, it indicates that the module is busy, and no working mode detection will be performed at this time; When the module AUX output high level within 1ms, will complete the mode switching work.
3	After the user switches to a new operating mode, at least 2ms after the rising edge of AUX is required for the module to actually enter that mode; If AUX stays high, then the mode switching will take effect immediately.
4	The module resets the user parameters when the user enters from mode 3 (sleep mode) or during a reset, during which the AUX output goes low.
5	Due to the characteristics of LoRa modulation, the information transmission delay is much longer than FSK, such as in 2.4kbps air speed, 100 bytes of transmission delay is about 1.5 seconds, it is recommended that customers do not carry out the transmission of large amounts of data at low air speeds, so as to avoid data loss due to the accumulation of data caused by the communication anomaly.

Operating mode

The module has four operating modes, which are set by pins M1 and M0; details are shown in the table below:

Mode（0- 3）	M1	M0	Mode Introduction	Remark
0 General Mode	0	0	Serial open, wireless open, transparent transmission	The receiver must be mode 0, 1
1 Wake-up mode	0	1	Serial port open, wireless open; The only difference with mode 0: before the packet is transmitted, the wake-up code is automatically increased so as to wake up the receiver working in mode 2	Receiver can be mode 0 Receiver can be mode 1 Receiver can be mode 2
2 Power saving mode	1	0	Serial port reception is off, wireless is in Wake-on-Air mode, and when wireless data is received, the serial port is opened to send out the data.	Transmitter must be in mode 1

3 Sleep mode

1

1

Module goes to sleep and can receive parameter setting commands

Cannot transmit in this mode

Mode switching precautions

No	Remark
1	Users can combine M1 and M0 with high and low levels to determine the module working mode. The 2 GPIOs of MCU can be used to control the mode switching; When changing M1, M0: If the module is idle, it can start working according to the new mode after 1ms; If the module has serial data that has not yet finished transmitting through wireless, it can enter the new working mode only after the transmitting is finished; If the module receives wireless data and sends out the data through the serial port, it needs to finish sending out before it can enter the new working mode; So the mode switching can only be effective when AUX outputs 1, otherwise the switching will be delayed.
2	For example, if the user inputs a large amount of data continuously and switches modes at the same time, the switching mode operation is invalid at this time; the module will process all the user data before detecting a new mode;   So the general recommendation is: detect the output state of AUX pin, wait for 2ms after the output high level before switching.
3	When the module is switched to hibernate mode from other modes, if there is data that has not been processed;   The module will process this data (both receive and transmit) before entering sleep mode. This feature can be used for fast hibernation to save power consumption; for example: the transmitter module works in mode 0, the user initiates the serial data “12345”, and then does not have to wait for the AUX pin to be idle (high), it can be directly switched to hibernation mode and the user’s main MCU is immediately hibernated, and the module automatically sends all the user’s data wirelessly. After sending out all the user data through wireless, the module will automatically enter hibernation within 1ms; Thus saving MCU’s working time and reducing power consumption.
4	Similarly, any mode switching can utilize this feature, the module will automatically enter a new mode within 1ms after processing the current mode event; thus saving the user the work of querying the AUX, and can achieve the purpose of fast switching; For example, switching from transmitter mode to receiver mode; the user MCU can also enter hibernation before mode switching, and use the external interrupt function to obtain the AUX change, so as to carry out mode switching.
5	This operation method is very flexible and efficient, completely designed in accordance with the user’s MCU operating convenience, and can minimize the workload of the entire system, improve system efficiency and reduce power consumption.

General mode (mode 0)

Type

When M0 = 0 and M1 = 0, the module operates in mode 0

transmitter

Module receives user data from the serial port, the module transmits wireless data packet length of 58 bytes, when the amount of data input by the user reaches 58 bytes, the module will start the wireless transmission, at this time, the user can continue to input the data that need to be transmitted; when the user needs to transmit bytes less than 58 bytes, the module waits for the 3 bytes of time, if there is no user data continue to input, it is considered to be the termination of the data, at this time, the module will be all the data packets

	through the wireless sent; when the module receives the first user data, will AUX output low level, when the module puts all the data into the RF chip and starts to transmit, AUX output high level;
receiver	The module always turns on the wireless receive function and can receive packets sent from mode 0 and mode 1; After receiving the packet, the module AUX outputs a low level, and after a delay of 5ms, it starts to send out the wireless data through the TXD pin of the serial port, and after all the wireless data are output through the serial port, the module outputs the AUX to a high level.

WOR mode (mode 1)

Type	When M0 = 1 and M1 = 0, the module operates in mode 1
transmitter	The conditions for the module to start packet transmitting and the AUX function are equivalent to mode 0; the only difference is: the module will automatically add a wake-up code before each packet, and the length of the wake-up code depends on the wake-up time set in the user’s parameter; the wake-up code is intended to be used to wake up the receiver module working in mode 2; so the data transmitted in mode 1 can be received by modes 0, 1 and 2.
receiver	Equivalent to mode 0.

Power saving mode (mode 2)

Type	When M0 = 0 and M1 = 1, the module operates in mode 2
transmitter	The module is in hibernation state, the serial port is closed and cannot receive the serial data from the external MCU, so this mode does not have the wireless transmitting function.
receiver	In Mode 2, the transmitter is required to work in Mode 1; listen to the wake-up code at regular intervals, once a valid wake-up code is received, the module will continue to be in the receiving state and wait for the whole valid packet to be received; then AUX outputs a low level, and after a delay of 5ms, it opens the serial port and sends out the received wireless data through TXD, and after that, it outputs a high level from AUX; the module continues to enter the “sleep – listen” operating state (polling); by setting different wake-up times, the module has different receiving response delays (maximum 2s) and average power consumption (minimum 30u The wireless module continues to enter the “sleep-listening” working state (polling); by setting different wake-up times, the module has different reception response delays (up to 2s) and average power consumption (minimum 30uA); the user needs to achieve a balance between the communication delay time and the average power consumption.

Deep sleep mode (mode 3)

Type	When M0 = 1 and M1 = 1, the module operates in mode 3
transmitter	Cannot transmit wireless data.
receiver	Cannot receive wireless data.
configuration	The hibernation mode can be used for module parameter setting, using the serial port 9600, 8N1, to set the module operating parameters through a specific command format.
note	When entering from hibernation mode to other modes, the module will reconfigure the parameters, and during the configuration process, AUX stays low; when finished, it outputs a high level, so it is recommended that the

Register read/write control

Command Introduction
The list of supported commands in hibernation mode (Mode 3: M0=1, M1=1) is as follows (only 9600, 8N1 format is supported at the time of setting):

No	Command format	Explanation
1	C0+Operating parameters	Send C0 + 5 bytes of operating parameters in hexadecimal format, totaling 6 bytes, must be sent continuously (power-down saved)
2	C1+C1+C1	Sending three C1 in hexadecimal format, the module returns the saved parameters, which must be sent continuously.
3	C2+Operating parameters	Sending C2+5 bytes of operating parameters in hexadecimal format, totaling 6 bytes, must be sent continuously (power down is not saved)
4	C3+C3+C3	Send three C3 in hexadecimal format, the module returns the version information, must be sent continuously.
5	C4+C4+C4	Send three C4 in hexadecimal format, the module will generate a reset, must be sent continuously.

Reading of operating parameters

command format	explanation
C1+C1+C1	In hibernation mode (M0=1, M1=1), issue the command (in HEX format): C1 C1 C1, to the module serial port. The module will return the current configuration parameters, e.g., C0 00 00 1A 06 44.

Version number reading

command format

explanation

C3+C3+C3

In sleep mode (M0=1, M1=1), send a command (in HEX format) to the module serial port: C3 C3 C3, the The module will return the current configuration parameters, for example: C3 32 XX YY; C3 is the command header, 32 represents the product model, XX represents the version number, YY represents the interface format + module maximum power value (hexadecimal). 0x10 for TTL interface, 0x40 for RS232, 0x80 for RS485

Reset command

command format	explanation
C4+C4+C4	In hibernation mode (M0=1, M1=1), send a command (in HEX format) to the module serial port: C4 C4 C4, the The module will generate a reset; During the reset process, the module performs a self-test and AUX outputs a low level; after the reset is completed, AUX outputs a high level and the module starts to work normally; At this time, mode switching or initiating the next command can be performed.

EWM32M-xxxT20S Register Description

	Name	Description				Remark
0	HEAD	Fixed 0xC0 or 0xC2, indicating that this frame data is a control command				Must be 0xC0 or C2 C0: The set parameters are saved by power- down. C2: The set parameters will not be saved by power-down.
1	ADDH	Module address high byte (default 00H)				00H-FFH
2	ADDL	Module address low byte (default 00H)				00H-FFH
3	SPED	7	6	Serial port parity bit		Serial port modes can be different on both sides of the communication
		0	0	8N1 (default)
		0	1	8O1
		1	0	8E1
		1	1	8N1 (00 equivalent)
		5	4	3	TTL serial port rate（bps）	The baud rate of both sides can be different The serial port baud rate is independent of the wireless transmission parameters and does not affect the wireless transceiver characteristics.
		0	0	0	The serial port baud rate is 1200
		0	0	1	The serial port baud rate is 2400
		0	1	0	The serial port baud rate is 4800
		0	1	1	The serial port baud rate is 9600 （default）
		1	0	0	The serial port baud rate is 19200
		1	0	1	The serial port baud rate is 38400
		1	1	0	The serial port baud rate is 57600
		1	1	1	The serial port baud rate is 115200
		2	1	0	Universal Radio Air Rate（bps）	The lower the air rate, the longer the distance, the stronger the anti-interference performance, and the longer the sending time. The airborne wireless transmission rate must be the same for both sides of the communication.
		0	0	0	Airspeed 2.4k
		0	0	1	Airspeed 2.4k
		0	1	0	Airspeed 2.4k（default）
		0	1	1	Airspeed 4.8k
		1	0	0	Airspeed 9.6k
		1	0	1	Airspeed 19.2k
		1	1	0	Airspeed 19.2k
		1	1	1	Airspeed 19.2k
4	CHAN	General Model
		7	6	5	Retain unused	Write 0

		communication channel									00H-1FH, corresponding to 410～441MHz 00H-45H, corresponding to 862-930MHz
		4 – 0, corresponding to (410MHz + CHAN * 1MHz), default 17H (433MHz) (for 400 band) 4 – 0, corresponds to (862MHz + CHAN * 1MHz), default 06H (868MHz) (applicable to 900 band)
5	OPTIO N	7	Fixed-point transmit enable bit (MODBUS-like)								When it is 1, the first 3 bytes of each user data frame are used as high and low address and channel. When transmitting, the module changes its own address and channel, and when finished, restores the original settings.
		0	Transparent transmission mode
		1	Fixed-point transmission mode
		6	IO drive mode (default 1)								This bit is used to enable the module’s internal pull-up resistor. The open drain method level adaptation is more robust and may require an external pull-up resistor in some cases.
		1	TXD, AUX push-pull outputs, RXD pull-up inputs
		0	TXD, AUX open output, RXD open input
		5	4		3	Wireless Wake-Up Time					Both transceiver modules work in mode 0. This delay time is invalid and can be any value; The transmitter works in mode 1 and will continuously transmit the wake-up code for the corresponding time; The receiver works in mode 2, this time is the listening interval time (wireless wake-up) of the receiver, and can only receive data from the transmitter working in mode 1.
		0	0		0	250ms（default）
		0	0		1	500ms
		0	1		0	750ms
		0	1		1	1000ms
		1	0		0	1250ms
		1	0		1	1500ms
		1	1		0	1750ms
		1	1		1	2000ms
		2	FEC Switch								When FEC is turned off, the actual data transmission rate is increased, but the anti-interference ability is weakened, and the distance is slightly closer, so please choose according to the actual application; Both sides of communication must be on or off.
		0	Turn off FEC error correction
		1	Turn on FEC error correction (default)
		1	0		Transmit power (approximate)						The external power supply must provide more than 250mA of current output capability and ensure that the power supply ripple is less than 100mV; It is not recommended to use lower power transmission, its power utilization efficiency is not high.
		0	0		20dBm（default）
		0	1		17dBm
		1	0		14dBm
		1	1		10dBm
Example (Meaning of the byte “SPED” in serial number 3):
Binary bits of this byte				7		6	5	4		3		2	1	0
Specific value (user-configurable)				0		0	0	1		1		0	1	0
Representation				Serial port parity bit 8N1			Serial port baud rate of 9600					Air rate of 2.4k
Corresponding hexadecimal				1					A

Factory Default Parameter

Model number

Factory default parameter value: C0 00 09 00 00 00 1A 00 17 03 00 00

Module Model	frequency	Address	channel	airspeed	baud	Serial Port Format	transmission power
EWM32M- 433T20S	433.125MH z	0x0000	0x17	2.4kbps	9600	8N1	20dbm
EWM32M- 900T20S	868.125MH z	0x0000	0x12	2.4kbps	9600	8N1	20dbm

AT command

• Using AT instructions for parameter configuration or querying needs to be done in the configuration mode;
• AT instructions are used in the configuration mode. AT instructions are divided into three categories in total: command instructions, setup instructions and query instructions;
• Users can pass “AT+HELP=?” Query to the AT instruction set supported by the module, the baud rate adopted by AT instruction is 9600 8N1;
• Will be limited when the input parameters exceed the range, please do not let the parameters exceed the range to avoid unknown situation.

AT command table

Command instruction	Description	Example	Example Description
AT+IAP (use with caution, see this article 8.3 Notes on Upgrading Firmware on Serial Ports for details)	Entering IAP upgrade mode	AT+IAP	Enter IAP upgrade mode
AT+RESET	Device reboot	AT+RESET	Reboot the device
AT+DEFAULT	Configuration parameters are restored to default and the device reboots	AT+DEFAULT	Configuration      parameters are restored to default

Setup command	Description	Example	Example Description
AT+UART=baud,parity	Setting the Baud Rate and Checksum	AT+UART=3,0	Set baud rate to 9600, 8N1
AT+RATE=rate	Setting the Air Rate	AT+RATE=7	Set the air rate to 19.2K
AT+WOR=role	Set WOR role and period	AT+WOR=0	Set to WOR receive
AT+POWER=power	Set Transmit Power	AT+POWER=0	Set the transmit power to 30dBm
AT+TRANS=mode	Setting the Transmit Mode	AT+TRANS=1	Set to fixed point mode

AT+LBT=lbt	Setting the Listen Before Talk switch	AT+LBT=1	Set on, refer to section 7.5 LBT enable for details.
AT+ADDR=addr	Setting the Module Address	AT+ADDR=1234	Set the module address to 1234
AT+CHANNEL=channel	Sets the module operating channel	AT+CHANNEL=23	Set frequency to 433.125M
AT+NETID=netid	Setting the Network ID	AT+NETID=2	Set the network ID to 2
AT+KEY=key	Set module key	AT+KEY=1234	Set module key to 1234
AT+DELAY=delay	Setting the WOR delayed sleep time	AT+DELAY=1000	Set WOR delayed sleep time to 1000ms.
AT+SWITCH=switch	Setting         the        software switching mode switch	AT+SWITCH=1	Setting on and allowing software switching
AT+SWITCH=switch	Setting         the        software switching mode switch	AT+SWITCH=1	Set on in configuration mode to allow software switching.
AT+MODE=mode	Switching Operating Mode	AT+MODE=0	Switch to pass-through mode

Query command	Description	Return example	Example Description
AT+HELP=?	Query AT Command Table		Return  to AT  Command Table
AT+DEVTYPE=?	Query       Module       Model Number	DEVTYPE=EWM32M- 433T20S	Return to Module Model Number
AT+FWCODE=?	Query Firmware Code	FWCODE=xxxx-x-xx	Return to Firmware Version
AT+UART=?	Query baud rate and parity	AT+UART=3,0	Returns baud rate of 9600, 8N1
AT+RATE=?	Query Air Rate	AT+RATE=7	Returns the air rate as 19.2K
AT+WOR=?	Query WOR Role	AT+WOR=0	Return to WOR receive
AT+POWER=?	Query Transmit Power	AT+POWER=0	Return to transmit power 20dBm
AT+TRANS=?	Query Transmit Mode	AT+TRANS=1	Return to fixed point mode
AT+LBT=?	Query Listen Before Talk function switch	AT+LBT=1	Return to LBT switching status
AT+ADDR=?	Query Module Address	AT+ADDR=1234	Return module address is 1234
AT+CHANNEL=?	Query  Module  Operating Channel	AT+CHANNEL=23	Returns the frequency as 433.125M
AT+NETID=?	Query Network ID	AT+NETID=2	Returns the network ID as 2
AT+KEY=?	Query Module Key		Returns ERR
AT+DELAY=?	Query WOR delayed sleep time	AT+DELAY=1000	Returns WOR delayed sleep time of 1000ms.
AT+SWITCH=？	Query software switch mode switch	AT+SWITCH=0	Software switching mode off
AT+MODE=？	Query      current      working	AT+MODE=0	Returns the current pass-

mode (all modes can be queried)

through mode

AT Parameter Analysis
When the serial port receives the correct command, the serial port will return “Command = OK”, otherwise it will return “=ERR”.

Command parameter	Parameter significance
Baud（serial port baud rate）	0:1200        1:2400        2:4800        3:9600 4:19200      5:38400      6:57600      7:115200
Parity（serial port parity bit）	0:8N1           1:8O1           2:8E1           3:8N1
Rate（airspeed）	0:2.4K         1:2.4K         2:2.4K         3:4.8K 4:9.6K         5:19.2K         6:19.2K    7:19.2K
Role（WOR role）	0:Receive 1:Send
Period（WOR cycle）	0:500ms      1:1000ms    2:1500ms    3:2000ms 4:2500ms    5:3000ms    6:3500ms    7:4000ms
Power（transmission power）	0:20dBm      1:17dBm      2:14dBm      3:10dBm
Mode（transfer mode）	0:Transparent 1:Fixed point
LBT(listen before talk)	0:off 1:on
Addr（Module Address）	Module address 0~65535 (decimal)
Channel（module channel）	Module channel 0~45 (decimal)
Netid（Internet ID）	Module Network 0~255 (decimal)
Key（keys）	Module Key 0~65535 (decimal)
Delay（WOR delayed sleep）	Delay Sleep 0~65535 (decimal)
Mode(operating mode)	0: Transmission mode 1: Wake-up mode 2: Power saving mode 3: Sleep mode

Serial Port Upgrade Firmware Notes
If customers need to upgrade the firmware, they need to find the corresponding BIN file provided by the official, and then use the upper computer provided by the official to upgrade the firmware, generally users do not need to upgrade the firmware, please do not use the “AT+IAP” command.
The necessary pins for upgrading must be pinned out (M1, M0, AUX, TXD, RXD, VCC, GND), and then send “AT+IAP” command to enter the upgrade mode in the configuration mode, if you need to exit the IAP upgrade mode, you need to keep powering up and wait for 60 seconds, and the program will be automatically exited, or else it will enter the upgrade mode indefinitely even if it is rebooted. If you need to exit IAP upgrade mode, you need to keep power on and wait for 60 seconds, the program will exit automatically, otherwise, even if you reboot, it will enter upgrade mode indefinitely. After entering the upgrade mode, the baud rate will be automatically switched to 115200 until it exits automatically, during which a log will be output.

Configuration instructions for the host computer

The following figure shows the configuration upper display interface of EWM32M-900T20S as an example. Users can switch to the command mode through M0 and M1 for quick configuration and reading of parameters in the upper display.

In the configuration of the host computer, the module address, frequency channel, network ID, and key are in decimal display mode; where each parameter takes the range of values:

• Network address: 0～65535
• Frequency channel: 0～45
• Network ID: 0～255
• Key: 0～65535

Hardware design

• It is recommended to use a DC regulated power supply to power this module, the power supply ripple factor should be as small as possible, and the module should be reliably grounded;
• Please pay attention to the correct connection of the positive and negative terminals of the power supply, such as reverse connection may cause permanent damage to the module;
• Please check the power supply to ensure that it is between the recommended supply voltages, if it exceeds themaximum value it may cause permanent damage to the module;
• Please check the power supply stability, the voltage should not fluctuate significantly and frequently;
• In the design of power supply circuit for the module, it is often recommended to retain more than 30% of the margin, there is the whole machine is conducive to long-term stable work;
• Module should be as far away as possible from the power supply, transformers, high-frequency alignments and other electromagnetic interference in the larger part;
• High-frequency digital alignment, high-frequency analog alignment, power supply alignment must be avoided below the module, if you really need to go through the module below, assuming that the module is welded in the Top Layer, the Top Layer in the contact part of the module to lay the ground copper (all paved with copper and a good ground), it 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 randomly route the module in the Bottom Layer or any other layer, which will affect the spuriousness of the module as well as the reception sensitivity to varying degrees;
• Assuming that there is a large electromagnetic interference around the module device will also greatly affect the performance of the module, according to the intensity of the interference is recommended to stay away from the module, if the situation permits you can do appropriate isolation and shielding;
• Assume that there is a large electromagnetic interference around the module alignment (high-frequency digital, high-frequency analog, power supply alignment) will also greatly affect the performance of the module, according to the intensity of the interference is recommended to be appropriate away from the module, if the situation permits you can do appropriate isolation and shielding;
• Communication line if you use 5V level, must be connected in series with 1k-5.1k resistor (not recommended, there is still a risk of damage);
• Try to stay away from some TTL protocols where the physical layer is also 2.4GHz, e.g. USB3.0;
• The antenna mounting structure has a big impact on the module performance, make sure the antenna is exposed and preferably vertically upward;
• When the module is installed inside the chassis, use a good quality antenna extension cable to extend the antenna to the outside of the chassis;
• The antenna must not be installed inside the metal shell, which will lead to a great weakening of the transmission distance.

Common problems

Unsatisfactory transmission distance

• When there are linear communication barriers, the communication distance will decay accordingly;
• Temperature, humidity, and co-channel interference, which will lead to higher communication packet loss rate;
• The ground absorbs and reflects radio waves, and the test results are poorer near the ground;
• Seawater has a strong ability to absorb radio waves, so the effect of the seaside test is poor;
• Metal objects near the antenna, or placed in a metal shell, the signal attenuation will be very serious;
• Wrong power register setting, air rate setting is too high (the higher the air rate, the closer the distance);
• Low voltage of power supply at room temperature is lower than the recommended value, the lower the voltage the lower the hair power;
• The use of antenna and module matching degree is poor or the antenna itself quality problems.

Modules are fragile

• Please check the power supply to ensure that it is between the recommended supply voltages, if it exceeds the maximum value it will cause permanent damage to the module;
• Please check the power supply stability, the voltage can not be substantial frequent fluctuations;
• Please ensure that the installation and use process anti-static operation, high-frequency device electrostatic sensitivity;
• Please ensure that the installation and use of the process of humidity should not be too high, part of the components for humidity-sensitive devices;
• If there is no special demand is not recommended to be used at too high or too low a temperature.

BER is too high

• Near the same frequency signal interference, away from the source of interference or modify the frequency and channel to avoid interference;
• Poor power supply may also cause garbled code, be sure to ensure the reliability of the power supply;
• Extension cords, feeder cords of poor quality or too long, can also cause high BER.

Antenna Selection

Enable both the IPEX-1 interface and the stamp hole interface at the same time, the IPEX-1 interface and the stamp hole interface can be selected at will

Welding instructions

Reflow temperature

Reflow Profile Characteristics		Leaded process assembly	Lead-free process assembly
Preheating/Holding	lowest temperature （Tsmin）	100℃	150℃
	highest temperature （Tsmax）	150℃	200℃
	Time（Tsmin~Tsmin）	60-120s	60-120s
slope of temperature rise（TL~Tp）		3℃/s，max	3℃/s，Max
liquid-phase temperature（TL）		183℃	217℃
Holding time above TL		60~90s	60~90s
Peak package temperature Tp		Users must not exceed the temperature indicated on the product’s “Moisture Sensitivity” label.。	The user must not exceed the temperature indicated on the product’s “Moisture Sensitivity” label.
Time (Tp) within 5°C of the specified classification temperature (Tc), see the following figure		20s	30s
Cooling slope (Tp~TL)		6℃/s，Max	6℃/s，Max
Time from room temperature to peak temperature		6 minutes, max.	8 minutes, max.
※The peak temperature (Tp) tolerance of the temperature profile is defined as the user’s upper limit.

Reflow temperature

Related Models

Product Model	Carrier frequenc ies Hz	transmis sion power dBm	Test Distance km	Airspeed bps	Package form	Product Size mm	Antenna form
E32-170T30D	170M	30	8	0.3k～9.6k	DIP	24*43	SMA-K
E32-433T20DC	433M	20	3	0.3k～19.2k	DIP	21*36	SMA-K
E32-433T20S1	433M	20	3	0.3k～19.2k	SMD	17*25.5	Stamp Holes
E32- 433T20S2T	433M	20	3	0.3k～19.2k	SMD	17*30	IPEX/Stamp Holes
E32-400T20S	433/470 M	20	3	0.3k～19.2k	SMD	16*26	IPEX/Stamp Holes
E32-433T30D	433M	30	8	0.3k～19.2k	DIP	24*43	SMA-K
E32-433T30S	433M	30	8	0.3k～19.2k	SMD	25*40.3	IPEX/Stamp Holes
E32-868T20D	868M	20	3	0.3k～19.2k	DIP	21*36	SMA-K
E32-868T20S	868M	20	3	0.3k～19.2k	SMD	16*26	IPEX/Stamp Holes
E32-868T30D	868M	30	8	0.3k～19.2k	DIP	24*43	SMA-K
E32-868T30S	868M	30	8	0.3k～19.2k	SMD	25*40.3	IPEX/Stamp Holes
E32-915T20D	915M	20	3	0.3k～19.2k	DIP	21*36	SMA-K
E32-915T20S	915M	20	3	0.3k～19.2k	SMD	16*26	IPEX/Stamp Holes
E32-915T30D	915M	30	8	0.3k～19.2k	DIP	24*43	SMA-K
E32-915T30S	915M	30	8	0.3k～19.2k	SMD	25*40.3	IPEX/Stamp Holes

Antenna Guide

Antenna Recommendation
Antenna is an important role in the communication process, often poor-quality antenna will have a great impact on the communication system, so we recommend some of the antennas as a supporting our wireless module and the performance is more excellent and reasonably priced antennas.

Product Model	style	frequency band Hz	Interface	Gain dBi	Heightm m	Feeder cm	Functional Features
TX433-JZ-5	Glue Stick Antennas	433M	SMA-J	2.0	52	–	Ultra Short Straight, Omni- Directional Antenna
TX433-JZG-6	Glue Stick Antenna	433M	SMA-J	2.5	62	–	Omni-Directional Antenna
TX433-JW-5	Rubber Stick Antenna	433M	SMA-J	2.0	50	–	Bent Rubber Stick, Omni- Directional Antenna
TX433-JWG-7	Rubber Stick Antenna	433M	SMA-J	2.5	75	–	Bent Rubber Stick, Omni Antenna
TX433-JK-11	Rubber Stick Antenna	433M	SMA-J	2.5	110	–	Bendable Rubber Stick, Omni- directional Antenna
TX433-XPL-100	Suction Cup Antenna	433M	SMA-J	3.5	185	100	Small Suction Cup Antenna, Cost Effective
TX433-XP-200	Suction Cup Antenna	433M	SMA-J	4.0	190	200	Neutral Suction Cup Antenna, Low Loss
TX433-XPH-300	Suction Cup Antenna	433M	SMA-J	6.0	965	300	Large Suction Cup Antenna, High Gain
TX490-JZ-5	Rubber Stick Antenna	470/490M	SMA-J	2.0	50	–	Ultra Short Straight, Omni- directional Antenna
TX490-XPL-100	Suction Cup Antenna	470/490M	SMA-J	3.5	120	100	Small Suction Cup Antenna, Cost Effective

Batch packing method

Revision history

Version	Date	Description	Issued by
1.0	2025-01-23	Initial version	Lei
1.1	2025-02-07	Recommended Wiring Diagram to Add Reserved Pull-Up Resistor Description	Lei

About us

• Technical support: support@cdebyte.com
• Documents and RF Setting download link: www.cdebyte.com
• Thank you for using Ebyte products! Please contact us with any questions or suggestions: info@cdebyte.com
• Phone: +86 028-61399028
• Web: www.cdebyte.com
• Address: B5 Mould Park, 199# Xiqu Ave, High-tech District, Sichuan, China

Copyright ©2012–2025，Chengdu Ebyte Electronic Technology Co.,Ltd.

Documents / Resources

EBYTE EWM32M-xxxT20S AT Directive 20dBm Small Form Factor LoRa Wireless Module [pdf] User Manual E32-170T30D, E32-433T20DC, E32-915T30D, E32-915T30S, EWM32M-xxxT20S AT Directive 20dBm Small Form Factor LoRa Wireless Module, EWM32M-xxxT20S, AT Directive 20dBm Small Form Factor LoRa Wireless Module, Small Form Factor LoRa Wireless Module, LoRa Wireless Module, Module

References

• User Manual