RAK RAK1920 User manual

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RAK1920 Quick Start Guide
Prerequisite
What Do You Need?
Before going through each and every step on using the RAK1920 WisBlock module, make sure to prepare the
necessary items listed below:
Hardware
RAK1920
Your choice of WisBlock Base
Your choice of WisBlock Core
USB Cable
Li-Ion/LiPo battery (optional)
Solar charger (optional)
Grove PIR Motion Sensor (AS312)
Software
Download and install Arduino IDE .
To add the RAKwireless Core boards on your Arduino board, install the RAKwireless Arduino BSP. Follow the
steps in the Github repo .
Product Configuration
Hardware Setup
RAK1920 is a WisBlock Interface module, which extends the WisBlock system with an adapter board to connect
Click Boards (MikroElektronika), QWICC (Sparkfun) based, and Grove (Seeed) based sensors to WisBlock.
For more information about the RAK1920, refer to the Datasheet.
RAK1920 module is part of the WisBlock Interface category, which connects to the base board through the IO slot.
Also, always secure the connection of the WisBlock module by using the compatible screws.

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Figure 1: RAK1920 connection to WisBlock Base
Assembling and Disassembling of WisBlock Modules
Assembling
As shown in Figure 2, the location for IO slot is properly marked by silkscreen. Follow carefully the procedure
defined in RAK5005-O module assembly/disassembly instructions to attach a WisBlock module. Once attached,
carefully fix the module with one or more pieces of M1.2 x 3 mm screws depending on the module.
Figure 2: RAK1920 connection to WisBlock Base
Disassembling
The procedure in disassembling any type of WisBlock modules is the same.
1. First, remove the screws.

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Figure 3: Removing screws from the WisBlock module
2. Once the screws are removed, check the silkscreen of the module to find the correct location where force can
be applied.
Figure 4: Detaching silkscreen on the WisBlock module
3. Apply force to the module at the position of the connector, as shown in Figure 5, to detach the module from the
baseboard.
Figure 5: Applying even forces on the proper location of a WisBlock module
📝 NOTE
If you will connect other modules to remaining WisBlock Base slots, check on the WisBlock Pin Mapper
tool for possible conflicts. RAK1920 uses UART and I2C communication lines, and it can cause possible
conflict especially on other WisBlock Modules connected to Slot A to D of the WisBlock Base.
After all this setup, you can now connect the battery (optional) and USB cable to start programming your WisBlock
Core.

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Figure 6: Battery connection to WisBlock Base Board
⚠ WARNING
Batteries can cause harm if not handled properly.
Only 3.7-4.2 V Rechargeable LiPo batteries are supported. It is highly recommended not to use other
types of batteries with the system unless you know what you are doing.
If a non-rechargeable battery is used, it has to be unplugged first before connecting the USB cable to
the USB port of the board to configure the device. Not doing so might damage the battery or cause a
fire.
Only 5 V solar panels are supported. Do not use 12 V solar panels. It will destroy the charging unit and
eventually other electronic parts.
Make sure the battery wires are matching the polarity on the WisBlock Base board. Not all batteries
have the same wiring.
Software Configuration and Example
The RAK1920 module is a sensor extension module, it supports several defacto-standard interfaces in the IoT
market and allows customers to integrate sensors manufactured by Mikroe, SparkFun, SeeedStudio, and others.
For example, the RAK1920 supports the Click Boards™ series of modules provided by Mikroe, Qwiic Connect™
sensor interface designed by SparkFun, and it supports all kinds of I2C module digital I/O, UART and ADC
sensors with a Grove™ interface.
Initial Test of the RAK1920 WisBlock Module
If you already installed the RAKwireless Arduino BSP , the WisBlock Core and example code should now be
available on the Arduino IDE.
1. You need to select first the WisBlock Core you have, as shown in Figure 6, Figure 7 and Figure 8.

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Using RAK4631 WisBlock Core
Figure 7: Selecting RAK4631 as WisBlock Core
Using RAK11200 WisBlock Core
Figure 8: Selecting RAK11200 as WisBlock Core
Using RAK11300 WisBlock Core

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Figure 9: Selecting RAK11300 as WisBlock Core
2. The Basic Sample Code for RAK1920 in Github will work on all WisBlock Core. You can open the the example
codes depending on your WisBlock Core, as shown in Figure 9, Figure 10 and Figure 11. For this guide we
will be using Grove PIR AS312
Sample code for RAK4631
Figure 10: Opening RAK1920 example code for RAK4631 WisBlock Core
Sample code for RAK11200

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Figure 11: Opening RAK1920 example code for RAK11200 WisBlock Core
Sample code for RAK11300
Figure 12: Opening RAK1920 example code for RAK11300 WisBlock Core
3. Once the example code is open, you can now select the right serial port and upload the code, as shown in
Figure 12 and Figure 13.

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Figure 13: Selecting the correct Serial Port
Figure 14: Uploading the RAK1920 example code
5. When you successfully uploaded the example sketch, open the Serial Monitor of the Arduino IDE to see the
sensor's reading logs. If you see the logs, as shown in Figure 14, then your RAK1920 is properly
communicating to the WisBlock core.

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Figure 15: RAK1920 sensor data logs
Sample code for other sensors
Grove Color TCS3472
MikroBUS Temperature TMP102
QWIIC AirQuality SGP30
Last Updated: 7/29/2022, 10:17:19 PM

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RAK1920 WisBlock Sensor Adapter Module
Datasheet
Overview
Description
The RAK1920 module, a part of the WisBlock Interface series, is a sensor extension module, which extends the
WisBlock system with an adapter board to connect Click Boards (MikroElektronika), QWICC (Sparkfun) based
and Grove (Seeed) based sensors to WisBlock. This module was designed to be part of a production-ready IoT
solution in a modular way and must be combined with a WisBlock Core and a Base module.
It supports several defacto-standard interfaces in the IoT market and allows you to integrate sensors manufactured
by Mikroe, SparkFun, SeeedStudio, and others. For example, the RAK1920 supports the Click Boards™ series of
modules provided by Mikroe, Qwiic Connect™ sensor interface designed by SparkFun. Also, it supports all kinds
of I2C module digital I/O, UART, and ADC sensors with a Grove™ interface.
Features
Interface to all Click Boards of Mikroe
Interface to all Qwiic sensors of SparkFun
Interface to all I2C and Digital I/O sensors of Grove
Interface to UART and ADC sensors options of Grove
Reserved I2C interface
3.3 V and 5 V sensors options
Specifications
Overview
The RAK1920 module supports Mikroe’s Click Boards, Sparkfun’s Qwiic Connect, and Seeed’s Grove sensors.
Figure 1 shows the sensors’ connector available in the RAK1920.
Figure 1: RAK1920 sensor extension interface
Mounting
Figure 2 shows how the RAK1920 module is integrated with the RAK5005-O baseboard, and the mounting sketch
is also shown.

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Figure 2: RAK1920 Mounting Sketch
Hardware
The hardware specification is categorized into four parts. It discusses the interfacing, its corresponding functions
and the diagram of the module as well. It also covers the electrical and mechanical parameters that include the
tabular data of the functionalities and standard values of the RAK1920 WisBlock Sensor Adapter Module.
Interfaces
Mikroe Click Boards Interfaces
The RAK1920 supports all the Click boards modules manufactured by Mikroe through the mikroBUS™ interface.
Figure 3 shows the pin out diagram of the mikroBUS.
Figure 3: Mikroe’s mikroBUS® interface
Pin No. Label Pin Definition
1 A0 Analog
2 RESET Reset
3 SPI_CS SPI Chip Select
4 SPI_CK SPI Clock
5 SPI_MISO SPI Master Input Slave Output

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Pin No. Label Pin Definition
Grove Sensor Interfaces
The RAK1920 module supports the Grove I2C and digital I/O sensors. Figure 4 shows the pin number and
definition of the Grove sensor. By default, VCC is connected to the 3.3 V line of the IO connector.
Figure 4: Grove Sensor interfaces
By default, the I2C is enabled in the RAK1920 module, but if it is required, the RAK1920 module can also support
sensors with Grove UART interface and ADC sensors. To enable the UART interface, a resistance connection
needs to be added by the customer. When using the Grove UART interface sensor module, replace R9 to R10 and
R11 to R12. When using Grove ADC interface (not ADC to I2C module) sensor module, replace R13 to R14 and
change R15 to R16.
6 SPI_MOSI SPI Master Output Slave Input
7 +3.3 V VCC 3.3 V Power
8 GND Reference Ground
9 GND Reference Ground
10 +5 V VCC 5.5 V Power
11 I2C_SDA I2C Data
12 I2C_SCL I2C Clock
13 UART_TX UART Transmit
14 UART_RX UART Receive
15 INT Hardware Interrupt
16 PWM PWM Input

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Figure 5: Replace connection resistance location
Figure 6 shows Grove sensor cables:
Figure 6: Grove Sensor cables
Table below shows Grove cable color and function definition.
Pin Color Function
Qwiic Sensor Interface
The RAK1920 module supports sensors manufactured by SparkFun through the Qwiic Connect interface. Figure 7
shows the Qwiic Connect interface:
Figure 7: Qwiic Connect® interface
Figure 8 shows a Qwiic Connect cable:
1 Yellow Digital IO1 /ADC CH1 /UART RX /I2C Cock
2 White Digital IO2 /ADC CH2 /UART TX /I2C Data
3 Red VCC
4 Black GND

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Figure 8: Qwicc Cable
The table below shows the Qwiic Connect cable color and function definition:
Pin Color Function
Reserved I2C Interface
The RAK1920 module has a reserved I2C interface, and it can be used for generic I2C interface sensors.
📝 NOTE:
The I2C interface only supports 3.3 V type of sensors. The reversed I2C interface is shown in Figure 9.
RAK 1920 Ver A.
3.3V
GND
SDA
SCL
Figure 9: Reserved I2C Interface
Electrical Characteristics
Absolute Maximum Ratings
Table below shows the absolute maximum ratings of the RAK1920 module:
Symbol Description Min. Nom. Max. Unit
1 Yellow I2C Clock
2 Blue I2C Data
3 Red 3.3 V
4 Black GND
VBAT Power supply for the module -0.5 4.2 V

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Symbol Description Min. Nom. Max. Unit
Recommended Operating Conditions
Table below shows the recommended operating conditions of the RAK1920 module:
Symbol Description Min. Nom. Max. Unit
Mechanical Characteristics
Board Dimensions
Figure 10: Mechanical Dimensions
WisConnector PCB Layout
Iout Boost converter output current 50 mA
VBAT Power supply for the module 2.6 4.2 V
3V3 3.3 V power supply 3.3 V
5V 5.5 V power supply 5.0 V

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Figure 11: WisConnector PCB footprint and recommendations
Schematic Diagram
Figure 12: Schematic Diagram
The following sections will describe the schematic of the RAK1920 module:

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Power Supply
IO Connector
Power Supply
The RAK1920 module supports the 5 V option. By default, the 3.3 V_S is used as the 3.3 V power source of
sensors. The module integrates a boost converter from the VBAT to 5 V. The VBAT is the battery output voltage,
usually between 3.7 V and 4.2 V. The EN pin enables the boost converter and is controlled by the WisBlock Core
module of the overall solution.
⚠ WARNING
The 3V3_S has to be enable via WB_IO2 GPIO. Otherwise, the module will not work.
Figure 13: Power supply
IO Connector
Figure 14: IO Connector
The RAK1920 module uses only a subset of all the pins available in the IO connector. These are shown in the
table below:

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Name Description CommentName Description Comment
IO Connector Pin Order
Figure 15 shows the IO connector’s pin order. The connector is located in the bottom layer of the RAK1920
module.
Figure 15: IO connector’s pin order
Last Updated: 7/29/2022, 10:17:19 PM
VBAT Battery output voltage Maximum: 4.2 V
3V3 3.3 V Default, sensor power supply
TXD1/RXD1 UART interface Connected only to the Click Boards connector.
CS/SCK/MOSI/MISO SPI interface Connected only to the Click Boards.
SDA/SCL I2C interface All I2C sensors
AIN0/AIN1 ADC input interfaces Grove or click Boards
INT Hardware Interrupt Connected only to the Click Boards connector.
RST Reset Connected only to the Click Boards connector.
PWM PWM input Connected only to the Click Boards connector.
EN Boost Converter Enable IO5
IO1/IO3 General purpose I/O Connected to Grove digital I/O sensors’ connectors.