Digi XBee 3 ZigBee User manual

Digi XBee® 3 ZigBee®
RF Module
User Guide

Revision history—90001539
Revision Date Description
C March
2018
Added the Get started with MicroPython section.
D November
2018
Added Bluetooth (BLE)support, SPIsupport, and Custom Default
ATcommands.
E April 2019 Added sleep support, file system, OTA file system updates, and several
MicroPython features.
F September
2019
Adding/updating relay frames. Added %P.
Added statuses to the 0x8A frame. Added location AT commands. Added DM.
Added the I/O support section. Added %P,*S,*V,*W,*X,*Y,SA,AZ,
FSINFOFULL,and DM. Updated RR. Updates to Remote AT Command
Request frame. Added location and BLEcommands. Added statuses to the
0x8A frame. Added frames Ox2C, 0x2D, 0x2E, 0x89, 0x98, 0xAC, 0xAE, and
0xAD. Added Get started with BLE and BLE reference sections. Made
changes to the CCAoperations section. Added reserved endpoints to 0x11
frame.
Trademarks and copyright
Digi, Digi International, and the Digi logo are trademarks or registered trademarks in the United
States and other countries worldwide. All other trademarks mentioned in this document are the
property of their respective owners.
© 2019 Digi International Inc. All rights reserved.
Disclaimers
Information in this document is subject to change without notice and does not represent a
commitment on the part of Digi International. Digi provides this document “as is,” without warranty of
any kind, expressed or implied, including, but not limited to, the implied warranties of fitness or
merchantability for a particular purpose. Digi may make improvements and/or changes in this manual
or in the product(s) and/or the program(s) described in this manual at any time.
Warranty
To view product warranty information, go to the following website:
www.digi.com/howtobuy/terms
Customer support
Gather support information: Before contacting Digi technical support for help, gather the following
information:
Product name and model
Digi XBee® 3 Zigbee® RF Module 2

Product serial number (s)
Firmware version
Operating system/browser (if applicable)
Logs (from time of reported issue)
Trace (if possible)
Description of issue
Steps to reproduce
Contact Digi technical support: Digi offers multiple technical support plans and service packages.
Contact us at +1 952.912.3444 or visit us at www.digi.com/support.
Feedback
To provide feedback on this document, email your comments to
[e-mail]
Include the document title and part number (Digi XBee® 3 Zigbee® RF Module, 90001539 F) in the
subject line of your email.
Digi XBee® 3 Zigbee® RF Module 3

Contents
Digi XBee® 3 Zigbee® RF Module
Applicable firmware and hardware 16
Change the firmware protocol 16
Regulatory information 16
Get started
Configure the XBee 3 Zigbee RF Module
19
19
Configure the device using XCTU
Custom defaults
Set custom defaults 19
Restore factory defaults 19
Limitations 19
Custom configuration: Create a new factory default 19
Set a custom configuration 20
Clear all custom configuration on a device 20
XBee bootloader 20
Send a firmware image 21
Software libraries 21
XBee Network Assistant 21
XBee Multi Programmer 22
Update the firmware over-the-air
Add the device to XCTU 24
Update to the latest firmware 24
Get started with MicroPython
About MicroPython 26
MicroPython on the XBee 3 Zigbee RF Module 26
Use XCTU to enter the MicroPython environment 26
Use the MicroPython Terminal in XCTU 27
MicroPython examples 27
Example: hello world 27
Example: enter MicroPython paste mode 27
Digi XBee® 3 Zigbee® RF Module 4

Digi XBee® 3 Zigbee® RF Module 5
Example:use the time module 28
Example: AT commands using MicroPython 28
MicroPython networking and communication examples 29
Zigbee networks with MicroPython 29
Example: forming and joining a Zigbee network using MicroPython 30
Example: network Discovery using MicroPython 31
Examples: transmitting data 32
Receiving data 33
Example: communication between two XBee 3 Zigbee modules 34
Exit MicroPython mode 37
Other terminal programs 37
Tera Term for Windows 37
Use picocom in Linux 38
Micropython help () 39
Secure access
Secure Sessions 42
Configure the secure session password for a device 42
Start a secure session 42
End a secure session 43
Secured remote AT commands 43
Secure a node against unauthorized remote configuration 43
Remotely configure a node that has been secured 44
Send data to a secured remote node 45
End a session from a server 45
Secure Session API frames 46
Secure transmission failures 47
Data Frames - 0x10 and 0x11 frames 47
Remote AT Commands- 0x17 frames 47
File system
Overview of the file system 49
Directory structure 49
Paths 49
Limitations 49
XCTU interface 50
Get started with BLE
Enable BLE on the XBee 3 Zigbee RF Module 52
Enable BLEand configure the BLEpassword 52
Get the Digi XBeeMobile phone application 53
Connect with BLEand configure your XBee 3 device 54
BLE reference
BLE advertising behavior and services 56
Device Information Service 56
XBee API BLEService 56
API Request characteristic 56
API Response characteristic 57

Digi XBee® 3 Zigbee® RF Module 6
Serial communication
Serial interface 59
UART data flow 59
Serial data 59
Serial buffers 60
Serial receive buffer 60
Serial transmit buffer 61
UART flow control 61
CTS flow control 61
RTS flow control 61
Break control 61
I2C 61
SPI operation
SPI communications 63
Full duplex operation 64
Low power operation 64
Select the SPI port 65
Force UART operation 66
Modes
Transparent operating mode 68
Serial-to-RF packetization 68
API operating mode 68
Command mode 68
Enter Command mode 69
Troubleshooting 69
Send AT commands 69
Response to AT commands 70
Apply command changes 70
Make command changes permanent 70
Exit Command mode 70
Idle mode 71
Transmit mode 71
Receive mode 72
Sleep mode 72
Zigbee networks
The Zigbee specification 74
Zigbee stack layers 74
Zigbee networking concepts 75
Device types 75
PAN ID 77
Operating channels 77
Zigbee application layers: in depth 78
Application Support Sublayer (APS) 78
Application profiles 78
Zigbee coordinator operation 80
Form a network 80

Digi XBee® 3 Zigbee® RF Module 7
Security policy 80
Channel selection 80
PAN ID selection 80
Persistent data 80
Coordinator startup 81
Permit joining 82
Reset the coordinator 82
Leave a network 83
Replace a coordinator (security disabled only) 83
Example: start a coordinator 84
Example: replace a coordinator (security disabled) 84
Router operation 85
Discover Zigbee networks 85
Join a network 85
Authentication 85
Persistent data 85
Router joining 86
Router network connectivity 87
End device operation 89
Discover Zigbee networks 89
Join a network 90
Parent child relationship 90
End device capacity 90
Authentication 90
Persistent data 91
Orphan scans 91
End device joining 91
Parent connectivity 92
Reset the end device 92
Channel scanning 92
Manage multiple Zigbee networks 93
Filter PAN ID 93
Configure security keys 93
Prevent unwanted devices from joining 93
Application messaging framework 94
Transmission, addressing, and routing
Addressing 96
64-bit device addresses 96
16-bit device addresses 96
Application layer addressing 96
Data transmission 96
Broadcast transmissions 97
Unicast transmissions 97
Address resolution 97
Address table 98
Group table 99
Binding transmissions 99
Multicast transmissions 99
Address resolution 99
Address resolution 99
Binding table 100
Fragmentation 100
Data transmission examples 100

Digi XBee® 3 Zigbee® RF Module 8
Send a packet in Transparent mode 100
Send data in API mode 101
API frame examples 102
RF packet routing 102
Link status transmission 103
AODV mesh routing 104
Many-to-One routing 107
High/Low RAM Concentrator mode 107
Source routing 107
Encrypted transmissions 112
Maximum RF payload size 112
Throughput 114
ZDO transmissions 114
Send a ZDO command 115
Receiving ZDO command and responses 115
Transmission timeouts 118
Unicast timeout 119
Extended timeout 119
Transmission examples 120
Zigbee security
Security overview 123
Network key 123
Link key 123
Preconfigured link key - moderate security 123
Well-known default link key - low security 124
Install code derived link key - high security 124
Join window 124
Key management 125
Centralized security 125
Distributed security 125
Device registration 125
Centralized trust center 126
Distributed trust center 126
Example: Form a secure network 126
Example: Join a secure network using a preconfigured link key 127
Example:Register a joining node without a preconfigured link key 128
Example: Register a joining node using an install code 129
Example:Deregister a previously registered device 129
Registration scenario 130
Network commissioning and diagnostics
Place devices 132
Test links in a network - loopback cluster 132
Transparent operating mode configuration (AP = 0) 132
RSSI indicators 132
Device discovery 133
Network discovery 133
ZDO discovery 133
Joining Announce 133
Commissioning pushbutton and associate LED 133
XBee 3 SMT 134

Digi XBee® 3 Zigbee® RF Module 9
XBee 3 Micro 134
XBee 3 Through-hole 135
Commissioning pushbutton 135
Associate LED 136
Binding 137
End_Device_Bind_req 137
Example of a End_Device_Bind_req 139
Group Table API 140
Add Group command 140
View group 141
Get Group Membership (1 of 2) 142
Get Group Membership (2 of 2) 144
Remove Group 145
Remove All Groups 146
Default responses 147
Common status codes 147
Manage End Devices
End device operation 150
Parent operation 150
End Device poll timeouts 151
End Device child table 151
Packet buffer usage 151
Non-Parent device operation 152
End Device configuration 152
Pin sleep 153
Cyclic sleep 155
Recommended sleep current measurements 161
Achieve the lowest sleep current 161
Compensate for switching time 161
Internal pin pull-ups 161
Transmit RF data 162
Receiving RF data 162
I/O sampling 162
Wake end devices with the Commissioning Pushbutton 162
Parent verification 162
Rejoining 163
Router/Coordinator configuration 163
RF packet buffering timeout 163
Child poll timeout 164
Adaptive polling 164
Transmission timeout 164
Short sleep periods 164
Extended sleep periods 164
Sleep examples 165
Example 1: Configure a device to sleep for 20 seconds, but set SN such that the On/sleep
line will remain de-asserted for up to 1 minute. 165
Example 2: Configure an end device to sleep for 20 seconds, send 4 I/O samples in 2
seconds, and return to sleep. 165
Example 3: configure a device for extended sleep: to sleep for 4 minutes. 166

Digi XBee® 3 Zigbee® RF Module 10
I/O support
Digital I/O support 168
Analog I/O support 168
Monitor I/O lines 169
I/O sample data format 170
API frame support 171
On-demand sampling 171
Example: Command mode 171
Example: Local AT command in API mode 172
Example: Remote AT command in API mode 173
Periodic I/O sampling 174
Source 174
Destination 174
Digital I/O change detection 174
I/O behavior during sleep 175
Digital I/O lines 175
Analog and PWM I/O Lines 175
AT commands
Networking commands 177
CE (Device Role) 177
ID (Extended PAN ID) 177
II (Initial 16-bit PAN ID) 177
ZS (Zigbee Stack Profile) 178
CR (Conflict Report) 178
NJ (Node Join Time) 178
DJ (Disable Joining) 179
NW(Network Watchdog Timeout) 180
JV (Coordinator Join Verification) 180
JN (Join Notification) 180
DO (Miscellaneous Device Options) 181
DC (Joining Device Controls) 181
C8 (Compatibility Options) 182
CB (Commissioning Pushbutton) 183
NR (Network Reset) 183
Operational Network Parameters commands 183
AI (Association Indication) 184
OP (Operating Extended PAN ID) 184
OI (Operating 16-bit PAN ID) 185
CH (Operating Channel) 185
NC (Number of Remaining Children) 185
Security commands 185
EE (Encryption Enable) 185
EO (Encryption Options) 186
DM (Disable Features) 186
KY (Link Key) 187
NK (Trust Center Network Key) 187
KT (Trust Center Link Key Registration Timeout) 188
I? (Install Code) 188
SA (Secure Access) 188
Zigbee Addressing commands 189
SH (Serial Number High) 189

Digi XBee® 3 Zigbee® RF Module 11
SL (Serial Number Low) 189
MY (16-bit Network Address) 189
MP (16-bit Parent Network Address) 190
DH (Destination Address High) 190
DL (Destination Address Low) 190
NI (Node Identifier) 191
NH (Maximum Unicast Hops) 191
BH (Broadcast Hops) 191
AR (Aggregate Routing Notification) 191
DD (Device Type Identifier) 192
ND (Network Discovery) 192
DN (Discover Node) 193
NT (Node Discover Timeout) 193
NO (Network Discovery Options) 194
NP (Maximum Packet Payload Bytes) 194
Zigbee addressing commands 194
TO (Transmit Options) 194
SE (Source Endpoint) 195
DE (Destination Endpoint) 195
CI (Cluster ID) 196
RF interfacing commands 196
PL (TX Power Level) 196
PP (Power at PL4) 197
SC (Scan Channels) 197
SD (Scan Duration) 198
AS (Active Scan) 198
ED (Energy Detect) 199
DB command 199
Serial interfacing commands 199
BD (UART Baud Rate) 199
NB (Parity) 200
SB (Stop Bits) 200
AP (API Enable) 201
AO (API Options) 201
AZ (Extended API Options) 202
RO (Packetization Timeout) 203
D6 (DIO6/RTS) 203
D7 (DIO7/CTS) 203
P3 (DIO13/DOUT Configuration) 204
P4 (DIO14/DIN Configuration) 204
Command mode options 205
CN (Exit Command mode) 205
CT (Command Mode Timeout) 205
GT (Guard Times) 205
CC (Command Character) 205
MicroPython commands 206
PS (Python Startup) 206
PY (MicroPython Command) 206
File system commands 207
FS (File System) 207
FK (File System Public Key) 209
BLE commands 209
BL(Bluetooth Address) 209
BT (Bluetooth Enable) 210
BI (Bluetooth Identifier) 210

Digi XBee® 3 Zigbee® RF Module 12
$S (SRP Salt) 210
$V, $W, $X, $Y commands (SRPSalt verifier) 211
Sleep commands 211
SM (Sleep Mode) 211
SP (Cyclic Sleep Period) 212
ST (Cyclic Sleep Wake Time) 212
SN (Number of Cycles Between ON_SLEEP) 212
SO (Sleep Options) 212
WH (Wake Host Delay) 213
PO (Polling Rate) 213
ET (End Device Timeout) 213
SI (Sleep Immediately) 214
I/O settings commands 214
D0 (DIO0/AD0/Commissioning Button Configuration) 214
D1 (AD1/DIO1/TH_SPI_ATTN Configuration) 215
D2 (DIO2/AD2/TH_SPI_CLK Configuration) 215
D3 (DIO3/AD3/TH_SPI_SSEL Configuration) 216
D4 (DIO4/TH_SPI_MOSI Configuration) 216
D5 (DIO5/Associate Configuration) 217
D8 (DIO8/DTR/SLP_RQ) 217
D9 (DIO9/ON_SLEEP) 218
P0 (DIO10/RSSI Configuration) 218
P1 (DIO11 Configuration) 219
P2 (DIO12/TH_SPI_MISO Configuration) 219
P5 (DIO15/SPI_MISO Configuration) 219
P6 (DIO16/SPI_MOSI Configuration) 220
P7 (DIO17/SPI_SSEL Configuration) 220
P8 (DIO18/SPI_CLK Configuration) 221
P9 (DIO19/SPI_ATTN Configuration) 221
PR (Pull-up/Down Resistor Enable) 222
PD (Pull Up/Down Direction) 223
M0 (PWM0 Duty Cycle) 223
M1 (PWM1 Duty Cycle) 223
LT (Associate LED Blink Time) 224
RP (RSSI PWM Timer) 224
I/O sampling commands 224
IR (I/O Sample Rate) 224
IC (Digital Change Detection) 225
AV (Analog Voltage Reference) 225
IS (Force Sample) 226
V+ (Supply Voltage Threshold) 226
Location commands 226
LX (Location X) 227
LY (Location Y) 227
LZ (Location Z) 227
Diagnostic commands 227
VR (Firmware Version) 227
VL (Version Long) 227
VH (Bootloader Version) 228
HV (Hardware Version) 228
%C (Hardware/Software Compatibility) 228
%P (Invoke Bootloader) 228
%V (Voltage Supply Monitoring) 229
EA (MAC ACK Failure Count) 229
TP (Temperature) 229

Digi XBee® 3 Zigbee® RF Module 13
CK (Configuration Checksum) 229
FR (Software Reset) 230
Memory access commands 230
AC (Apply Changes) 230
WR (Write) 230
RE (Restore Defaults) 231
Custom default commands 231
%F (Set Custom Default) 231
!C (Clear Custom Defaults) 231
R1 (Restore Factory Defaults) 231
Secure Session commands 232
*S (Secure Session Salt) 232
*V, *W, *X, *Y (Secure Session Verifier) 232
SA (Secure Access) 232
API Operation
API serial exchanges 235
AT commands 235
Transmit and Receive RF data 236
Remote AT commands 236
Source routing 236
Device Registration 237
API frame format 237
API operation (AP parameter = 1) 237
API operation with escaped characters (AP parameter = 2) 237
Send ZDO commands with the API 240
Example 242
Send Zigbee cluster library (ZCL) commands with the API 243
Example 246
Send Public Profile Commands with the API 248
Frame specific data 248
Example 251
Frame descriptions
AT Command frame - 0x08 255
AT Command - Queue Parameter Value frame - 0x09 257
Transmit Request frame - 0x10 259
Explicit Addressing Command frame - 0x11 262
Remote AT Command Request frame - 0x17 265
Create Source Route - 0x21 268
Register Joining Device - 0x24 270
BLE Unlock API frame - 0x2C 274
Example sequence to perform AT Command XBee API frames over BLE 276
User Data Relay frame - 0x2D 277
Example use cases 278
Example 278
Secure Session Control frame - 0x2E 279
AT Command Response frame - 0x88 283
Modem Status frame - 0x8A 285
Transmit Status frame - 0x8B 287
TX Status frame - 0x89 288
Receive Packet frame - 0x90 290

Digi XBee® 3 Zigbee® RF Module 14
Explicit Rx Indicator frame - 0x91 292
I/O Data Sample Rx Indicator frame - 0x92 295
Node Identification Indicator frame - 0x95 298
Remote Command Response frame - 0x97 301
Extended Modem Status frame - 0x98 303
Verbose Join status code descriptions 306
Route Record Indicator - 0xA1 312
Register Device Status - 0xA4 313
Many-to-One Route Request Indicator - 0xA3 315
BLE Unlock Response frame - 0xAC 316
User Data Relay Output - 0xAD 316
Example 317
Secure Session Response frame - 0xAE 317
Over-the-air firmware/file system upgrade process for Zigbee 3.0
FOTA upgrade image file formats 320
OTA/OTB file 320
fs.ota file 320
The OTA header 320
Hardware/software compatibility 320
Sub-elements and tags 320
Parse the image blocks 321
Storage 321
ZCL OTA messaging 321
Image Notify 322
Create the Image Notify request 322
Query Next Image request 324
Query Next Image response 326
Image Block request 328
Image Block response 330
Upgrade End request 333
Upgrade End response 334
ZCL OTA cluster status codes 337
OTA file system upgrades
OTA file system update process 340
OTA file system updates using XCTU 340
Generate a public/private key pair 340
Set the public key on the XBee 3 device 341
Create the OTA file system image 342
Perform the OTA file system update 343
OTA file system updates: OEM 344
Generate a public/private key pair 345
Set the public key on the XBee 3 device 345
Create the OTA file system image 345
Perform the OTA file system update 346

Digi XBee® 3 Zigbee® RF Module
This manual describes the operation of the XBee 3 Zigbee RF Module, which consists of Zigbee
firmware loaded onto XBee 3 hardware.
The XBee 3 Zigbee RF Modules provide wireless connectivity to end-point devices in Zigbee mesh
networks. Using the Zigbee 3.0 feature set, these devices are inter-operable with other Zigbee
devices, including devices from other vendors. With theXBee 3 Zigbee RF Module, users can have their
Zigbee network up-and-running in a matter of minutes without configuration or additional
development.
For information about XBee 3 hardware, see the XBee 3 RF Module Hardware Reference Manual.
Applicable firmware and hardware 16
Change the firmware protocol 16
Regulatory information 16
Digi XBee® 3 Zigbee® RF Module 15

Digi XBee® 3 Zigbee® RF Module Applicable firmware and hardware
Digi XBee® 3 Zigbee® RF Module 16
Applicable firmware and hardware
This manual supports the following firmware:
nv.10xx Zigbee
It supports the following hardware:
nXBee 3
Change the firmware protocol
You can switch the firmware loaded onto the XBee 3 hardware to run any of the following protocols:
nZigbee
n802.15.4
nDigiMesh
To change protocols, use the Update firmware feature in XCTU and select the firmware. See the
XCTU User Guide.
Regulatory information
See the Regulatory information section of the XBee 3 RF Module Hardware Reference Manual for the
XBee 3 hardware's regulatory and certification information.

Get started
Refer to the XBee Zigbee Mesh Kit User Guide for comprehensive instructions and examples on how to
get started with the XBee 3 Zigbee RF Module.
Digi XBee® 3 Zigbee® RF Module 17

Configure the XBee 3 Zigbee RF Module
19
19
19
20
21
21
21
Configure the device using XCTU
Custom defaults
Custom configuration: Create a new factory default
XBee bootloader
Send a firmware image
Software libraries
XBee Network Assistant
XBee Multi Programmer 22
Digi XBee® 3 Zigbee® RF Module 18

Configure the XBee 3 Zigbee RF Module Configure the device using XCTU
Digi XBee® 3 Zigbee® RF Module 19
Configure the device using XCTU
XBee Configuration and Test Utility (XCTU) is a multi-platform program that enables users to interact
with Digi radio frequency (RF) devices through a graphical interface. The application includes built-in
tools that make it easy to set up, configure, and test Digi RF devices.
For instructions on downloading and using XCTU, see the XCTU User Guide.
Custom defaults
Custom defaults allow you to preserve a subset of the device configuration parameters even after
returning to default settings using RE (Restore Defaults). This can be useful for settings that identify
the device—such as NI (Node Identifier)—or settings that could make remotely recovering the device
difficult if they were reset—such as ID (Extended PAN ID).
Note You must send these commands as local AT commands, they cannot be set using Remote AT
Command Request frame - 0x17.
Set custom defaults
Use %F (Set Custom Default) to set custom defaults. When the XBee 3 Zigbee RF Module receives %F
it takes the next command it receives and applies it to both the current configuration and the custom
defaults.
To set custom defaults for multiple commands, send a %F before each command.
Restore factory defaults
!C (Clear Custom Defaults) clears all custom defaults, so that RE (Restore Defaults) will restore the
device to factory defaults. Alternatively, R1 (Restore Factory Defaults) restores all parameters to
factory defaults without erasing their custom default values.
Limitations
There is a limitation on the number of custom defaults that can be set on a device. The number of
defaults that can be set depends on the size of the saved parameters and the devices' firmware
version. When there is no more room for custom defaults to be saved, any command sent immediately
after a %F returns an error.
Custom configuration: Create a new factory default
You can create a custom configuration that is used as a new factory default. This feature is useful if,
for example, you need to maintain certain settings for manufacturing or want to ensure a feature is
always enabled. When you use RE (Restore Defaults) to perform a factory reset on the device, the
custom configuration is set on the device after applying the original factory default settings.

Configure the XBee 3 Zigbee RF Module XBee bootloader
Digi XBee® 3 Zigbee® RF Module 20
For example, by default Bluetooth is disabled on devices. You can create a custom configuration in
which Bluetooth is enabled by default. When you use RE to reset the device to the factory defaults, the
Bluetooth configuration set to the custom configuration (enabled) rather than the original factory
default (disabled).
The custom configuration is stored in non-volatile memory. You can continue to create and save
custom configurations until the XBee 3 Zigbee RF Module's memory runs out of space. If there is no
space left to save a configuration, the device returns an error.
You can use !C (Clear Custom Defaults) to clear or overwrite a custom configuration at any time.
Set a custom configuration
1. Open XCTU and load your device.
2. Enter Command mode.
3. Perform the following process for each configuration that you want to set as a factory default.
a. Send the Set Custom Default command, AT%F. This command enables you to enter
a custom configuration.
b. Send the custom configuration command. For example: ATBT 1. This command sets
the default for Bluetooth to enabled.
Clear all custom configuration on a device
After you have set configurations using %F (Set Custom Default), you can return all configurations to
the original factory defaults.
1. Open XCTU and load the device.
2. Enter Command mode.
3. Send AT!C.
XBee bootloader
You can update firmware on the XBee 3 Zigbee RF Module serially. This is done by invoking the XBee 3
bootloader and transferring the firmware image using XMODEM.
This process is also used for updating a local device's firmware using XCTU.
XBee devices use a modified version of Silicon Labs' Gecko bootloader. This bootloader version
supports a custom entry mechanism that uses module pins DIN, DTR/SLEEP_RQ, and RTS.
To invoke the bootloader using hardware flow control lines, do the following:
1. Set DTR/SLEEP_RQ low (CMOS0V) and RTS high.
2. Send a serial break to the DIN pin and power cycle or reset the module.
3. When the device powers up, set DTR/SLEEP_RQ and DIN to low (CMOS0V) and RTS should be
high.
4. Terminate the serial break and send a carriage return at 115200 baud to the device.
5. If successful, the device sends the Silicon Labs' Gecko bootloader menu out the DOUT pin at
115200 baud.
6. You can send commands to the bootloader at 115200 baud.
Note Disable hardware flow control when entering and communicating with the bootloader.