Microchip Technology RN4020 User manual

2014-2022 Microchip Technology Inc. DS50002279D-page 1
RN4020
Features
• Fully certified Bluetooth®version 4.1 module
• On-board Bluetooth Low Energy 4.1 stack
• ASCII command interface API over UART
• Device Firmware Upgrade (DFU) over UART or Over
the Air (OTA)
• Microchip Low-energy Data Profile (MLDP) for serial
data applications
• Remote commands over-the-air
• 64 KB internal flash
• Compact form factor: 11.5 mm x 19.5 mm x 2.5 mm
• Castellated SMT pads for easy and reliable PCB
mounting
• Environmentally friendly, RoHS compliant
• Certifications: FCC, ISED, CE, QDID, VCCI, KCC
and NCC
Operational
• Single operating voltage: 1.8V to 3.6V (3.3V typical)
• Temperature range: -30°C to 85°C
• Low-power consumption
• Simple, UART interface
• Integrated Crystal, I2C Interface, Internal Voltage
Regulator, Matching Circuitry, and PCB Antenna
• Multiple IOs for control and status
• GPIO, ADC
• Three Pulse Width Modulation (PWM) outputs
RF/Analog Features
• ISM Band 2.402 to 2.480 GHz operation
• Channels 0-39
• RX Sensitivity: -92.5 dBm at 0.1% BER
• TX Power: -19.0 dBm to +7.5 dBm
• RSSI Monitor
MAC/Baseband/Higher Layer Features
• Secure AES128 encryption
• GAP, GATT, SM, L2CAP, and integrated public
profiles
• Create custom services using command API
• Keyboard I/O Authentication
• Software configurable role as peripheral or central
and client or server
• Built-in scripting capabilities for hostless operation
Applications
• Health/Medical Devices
- Glucose meters
- Heart rate
-Scale
• Sports Activity and Fitness
- Pedometer
- Cycling computer
- Heart rate
• Retail
- Point of Sale (POS)
- Asset tagging and tracking
- Proximity advertising
• Beacon Applications
• Internet of Things (IoT) Sensor tag
• Remote Control
- Embedded Device Control
- AV consoles and game controllers
• Wearable Smart Devices and Accessories
• Industrial Control
- Private (custom) services
- Low bandwidth cable replacement
• Smart Energy/Smart Home
Description
Microchip’s RN4020 Bluetooth Low Energy Module pro-
vides a highly integrated solution for delivering low-power
Bluetooth 4.1 solutions. The advanced command inter-
face offers rapid time to market. The RN4020 module
complies with Bluetooth specification version 4.1. The
module integrates RF, a baseband controller, and a com-
mand API processor, making it a complete Bluetooth Low
Energy solution. The RN4020 can be used with ultra-low
cost microcontroller for intelligent Bluetooth Low Energy
applications. For simple sensor applications, the RN4020
internal scripting capabilities enable basic functions to be
implemented without the need for external host MCU or
software development tools.
Bluetooth®Low Energy Module

RN4020
DS50002279D-page 2 2014-2022 Microchip Technology Inc.
TO OUR VALUED CUSTOMERS
It is our intention to provide our valued customers with the best documentation possible to ensure successful use of your Microchip
products. To this end, we will continue to improve our publications to better suit your needs. Our publications will be refined and
enhanced as new volumes and updates are introduced.
If you have any questions or comments regarding this publication, please contact the Marketing Communications Department via
E-mail at [email protected]. We welcome your feedback.
Most Current Data Sheet
To obtain the most up-to-date version of this data sheet, please register at our Worldwide Web site at:
http://www.microchip.com
You can determine the version of a data sheet by examining its literature number found on the bottom outside corner of any page.
The last character of the literature number is the version number, (e.g., DS30000000A is version A of document DS30000000).
Errata
An errata sheet, describing minor operational differences from the data sheet and recommended workarounds, may exist for current
devices. As device/documentation issues become known to us, we will publish an errata sheet. The errata will specify the revision
of silicon and revision of document to which it applies.
To determine if an errata sheet exists for a particular device, please check with one of the following:
• Microchip’s Worldwide Web site; http://www.microchip.com
• Your local Microchip sales office (see last page)
When contacting a sales office, please specify which device, revision of silicon and data sheet (include literature number) you are
using.
Customer Notification System
Register on our web site at www.microchip.com to receive the most current information on all of our products.
Table of Contents
1.0 Device Overview........................................................................................................................................................................... 3
2.0 General Specifications.................................................................................................................................................................. 6
3.0 Microcontroller to RN4020 Interface ............................................................................................................................................. 7
4.0 Physical Dimensions .................................................................................................................................................................... 8
5.0 Typical Application Schematic .................................................................................................................................................... 11
6.0 ASCII Command API .................................................................................................................................................................. 12
7.0 Supported Services .................................................................................................................................................................... 13
8.0 Regulatory Approval ................................................................................................................................................................... 15
9.0 Ordering Information................................................................................................................................................................... 21
Appendix A: Revision History ............................................................................................................................................................... 23
The Microchip Web Site ....................................................................................................................................................................... 25
Customer Change Notification Service ................................................................................................................................................ 25
Customer Support ................................................................................................................................................................................ 25

2014-2022 Microchip Technology Inc. DS50002279D-page 3
RN4020
1.0 DEVICE OVERVIEW
The RN4020 Bluetooth Low Energy RF module
integrates Bluetooth 4.1 radio baseband, MCU, digital
analog I/O, on-board stack, and ASCII command API.
Figure 1-1 shows the top view of the module. The
pinout of the module is shown in Figure 1-2, and the
description is presented in Tab l e 1 - 1 . Figure 1-3 lists all
the key components of the module.
FIGURE 1-1: RN4020 TOP VIEW
FIGURE 1-2: RN4020 PIN DIAGRAM
FIGURE 1-3: RN4020 BLOCK DIAGRAM
















 

 



*1'
$,2
$,2
$,2
8$57B7;
8$57B5;
:$.(B6:
&0'0/'3
*1'
9''
6&/
6'$
569'
3:03,2
5763,2
63,3,2
*1' 3,26&.3:0 3,2&63:0
3,2026,3:0 3,20,62 3,2/CTS
:$.(B+:
*1'
High-Performance
Integrated Antenna
128b AES Encryption
GPIO
10-bit ADC
UART
BTLE v 4.1 Core
with BT SIG Certified
Firmware GATT/GAP
UART Interface
3x Analog I/O
4 PWM I/O, I2C Comm.
1.8 –3.6V
Radio
Modem
64KB serial
Flash for
User profiles
and scripts
Crystal
RN4020 Bluetooth©4.1 Low Energy Module
VReg

RN4020
DS50002279D-page 4 2014-2022 Microchip Technology Inc.
TABLE 1-1: PIN DESCRIPTION
Pin Name Description Function
1 GND Ground Ground
2 AIO2 Bi-directional with programmable analog I/O 1.35V and 30 mA max out
3 AIO1 Bi-directional with programmable analog I/O 1.35V and 30 mA max out
4 AIO0 Bi-directional with programmable analog I/O 1.35V and 30 mA max out
5 UART TX UART Transmit (TX) Output
6 UART RX UART Receive (RX) Input
7 WAKE_SW
Deep Sleep Wake; active-high to wake module from
Deep Sleep. If the module runs without a host micro-
controller, connect the UART_RX pin to VDD via a
10K resistor to conserve power in Deep Sleep.
Input; weak pull down
8CMD/MLDP
Command or MLDP mode – In Command mode,
UART traffic is sent to the command interpreter. In
MLDP mode, UART traffic is routed to the MLDP
Bluetooth®LED connection, if active.
Input; Edge triggered; Change
from High to Low to enter CMD
mode from MLDP mode
9 GND Ground Ground
10
CONNECTION
LED
PIO[1]
SCK
PWM1
Default state is output. Active-high indicates the
module is connected to a remote device. Active-low
indicates a disconnected state. Configurable as
PIO[1] via software command. SCK for Diagnostics
and Factory Calibration if pin 17 is asserted.
• Connection Status Indicator
(Green LED)
• PIO[1]
•SCK
•PWM1
11
MLDP_EV
PIO[2]
CS
PWM2
Default function is output used for MLDP data event
indicator (Red LED). Active-high indicates MLDP
data received or UART console data pending. Low
level indicates no events. Event is only triggered in
MLDP mode, when CMD/MLDP (pin 8) is high.
Configurable as PIO[2] via “|I” and “|O” commands.
CS for Diagnostics and Factory Calibration if pin 17
is asserted.
• MLDP Data Indicator (Red
LED)
• PIO[2]
•CS
•PWM2
12
WS
PIO[3]
MOSI
PWM3
Default function is an output used for Activity
Indicator (Blue LED). High level indicates module is
awake and active. Low level indicates module is in a
Sleep state. Accessible as PIO[3] via “|>” and “|<”
commands. MOSI for Diagnostics and Factory
Calibration if pin 17 is asserted.
• WS (Blue LED)
• PIO[3]
•MOSI
•PWM3
13 PIO[4]
MISO
MISO for Diagnostics and Factory Calibration if pin
17 asserted.
• PIO[4]
•MISO
14 CTS
PIO[5]
Reserved for CTS if hardware flow control is enabled
on the UART; active-low.
• CTS (input)
• PIO[5]

2014-2022 Microchip Technology Inc. DS50002279D-page 5
RN4020
15 WAKE_HW
Hardware wake from Dormant state. Setting the
WAKE_HW (pin15) high wakes the module from Dor-
mant mode. During the module power up, if
WAKE_HW pin is flipped high and low for three
cycles (putting the WAKE_HW pin into high, low, and
then high again is considered as one flip cycle) in the
first five seconds, then the module performs a factory
Reset. If the WAKE_SW pin is high when a factory
Reset is performed, the factory Reset is a full reset.
Otherwise, it is a partial reset that retains the device
name, private service and scripts. Set WAKE_HW
pin to low in order to lower power consumption in
Deep Sleep and Dormant modes.
Active-high; internal pull down
16 GND Ground Ground
17 SPI/PIO SPI/PIO for pins 10-13; active-high Input with internal pull down;
selects SPI on pins 10-13
18 RTS
PIO[6]
Reserved for RTS if hardware flow control on UART
is enabled. If the data transmission to RN4020 must
be halted, assert RTS to high. RTS pin operates
independently from the CTS (pin 14).
• RTS (output)
• PIO[6]
19 PWM4
PIO[7] Spare PIO PIO[7]; Spare PIO configurable as
input or output
20 RSVD Do not connect. Factory diagnostics. No Connect
21 SDA SDA Data line of the I2C interface. The RN4020
always acts as the I2C Host. SDA
22 SCL I2C Clock SCL
23 VDD Supply voltage 1.8 to 3.6V
24 GND Ground Ground
TABLE 1-1: PIN DESCRIPTION (CONTINUED)
Pin Name Description Function
CAUTION
A full factory Reset erases scripts and sets the
device name to the serialized name. For more
information, refer to the SF Command in the
RN4020 Bluetooth Low Energy User's Guide
(DS70005191).

RN4020
DS50002279D-page 6 2014-2022 Microchip Technology Inc.
2.0 GENERAL SPECIFICATIONS
Table 2-1 provides the general specifications of the
module. Tab l e 2-2 and Tab l e 2-3 shows the weight and
dimensions, and electrical characteristics of the mod-
ule. Table 2-4 and Table 2-5 specify the current con-
sumption of the module.
TABLE 2-1: GENERAL SPECIFICATIONS
Specification Description
Standard Bluetooth®4.1
Frequency Band 2.4 ~ 2.48 GHz
Modulation Method GFSK
Maximum Data Rate 1 Mbps
Antenna PCB
Interface UART, PIO, AIO, SPI
Operation Range 100 meters(1)
Sensitivity -92.5 dBm at 0.1% BER
RF TX Power -19.0 dBm to +7.5 dBm
Temperature (operating) -30°C to +85°C
Temperature (storage) -40°C to +85°C
Humidity 10% ~ 90%
non-condensing
Note 1: Maximum range under ideal conditions
such as RF matching, line of sight, maxi-
mum power. Actual results may vary
depending on the customer’s design.
TABLE 2-2: WEIGHT AND DIMENSIONS
Specification Description
Dimensions 11.5 mm x 19.5 mm x 2.5 mm
Weight 1.2g
TABLE 2-3: ELECTRICAL
CHARACTERISTICS
Specification Description
Supply Voltage 1.8 to 3.6V DC
Working current Depends on profiles, 12 mA
typical
TABLE 2-4: CURRENT CONSUMPTION
Mode Typical Current at 3V
Dormant <900 nA
Deep Sleep <5.0 µA
Idle <1.5 mA
TX/RX active 16 mA
TABLE 2-5: CURRENT CONSUMPTION VS
RF TX POWER
RN4020, VDD = 3.3V, 25°C
TX Power (dBm) Id (mA)
-19.1 14.0
-15.1 14.4
-10.9 15.0
-6.9 15.9
-2.5 17.6
1.6 20.7
5.8 26.9
7.5 33.6

2014-2022 Microchip Technology Inc. DS50002279D-page 7
RN4020
3.0 MICROCONTROLLER TO
RN4020 INTERFACE
Figure 3-1 illustrates the interface between PIC
microcontroller and the RN4020 module.
The minimum interface consists of UART and
WAKE_HW lines. This enables the microcontroller to
communicate with the RN4020 module using ASCII
command API. The command API is described in
Section 6.0 “ASCII Command API”.
3.1 CTS/RTS Hardware Flow Control
For customer applications using the Microchip Low-
energy Data Profile, Pin 8 (CMD/MLDP) is required.
CTS/RTS hardware control is also required for this
service to avoid buffer overruns.
3.2 Microchip Low-energy Data Profile
(MLDP)
The Microchip Low-energy Data Profile is a private
BTLE service that provides a 50 kbps serial data trans-
port over Bluetooth Low Energy on the RN4020. Pin 8
(CMD/MLDP) is required. CTS/RTS hardware control
is also highly recommended for this service to avoid
data loss.
For more information on how to use the MLDP data ser-
vice, refer to RN4020 Bluetooth Low Energy
Module User’s Guide (DS70005191).
FIGURE 3-1: INTERFACE DESCRIPTION
Note: If the RN4020 is operated in a hostless mode (without a microcontroller), set the UART_RX pin to high
via a 10K resistor to reduce power consumption in Deep Sleep mode.

RN4020
DS50002279D-page 8 2014-2022 Microchip Technology Inc.
4.0 PHYSICAL DIMENSIONS
Figure 4-1 shows the physical dimensions for RN4020
module. Figure 4-2 illustrates the recommended PCB
layout. It is recommended that when laying out the
carrier board for the RN4020 module, the areas under
the antenna, RF test point (semi-circular pad), and
shielding connections do not contain surface traces,
ground planes, or exposed vias.
Figure 4-3 specifies the recommended mounting
details. For optimal radio performance, it is recom-
mended that the antenna end of the RN4020 module
protrudes at least 31 mm beyond any metal enclosure.
Figure 4-4 shows an example of good and acceptable
positioning of the RN4020 on the host PCB.
FIGURE 4-1: RN4020 MODULE DIMENSIONS

2014-2022 Microchip Technology Inc. DS50002279D-page 9
RN4020
FIGURE 4-2: RN4020 RECOMMENDED PCB FOOTPRINT
FIGURE 4-3: RN4020 MODULE MOUNTING DETAILS
PP
PP
PP
PP












       


'LPHQVLRQVDUHLQPLOOLPHWHUV
6KLHOG3DGV
&RUQHUV
[PP
 
.HHS2XW$UHDV


.HHSRXWKRVW3&%WRS
FRSSHUOD\HUWUDFHV
WRSUHYHQWSRVVLEOH
VKRUWFLUFXLWV
([WUDJURXQGSDG
DUHDRSWLRQDO
.HHSRXWKRVW3&%WRS
FRSSHUOD\HUWUDFHV
WRSUHYHQWSRVVLEOH
VKRUWFLUFXLWV

RN4020
DS50002279D-page 10 2014-2022 Microchip Technology Inc.
FIGURE 4-4: RN4020 HOST PCB EXAMPLE LAYOUT