RAK RAK1901 User manual

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RAK1901 Quick Start Guide
Prerequisite
What Do You Need?
Before going through each and every step on using the RAK1901 WisBlock module, make sure to prepare the
necessary items listed below:
Hardware
RAK1901 WisBlock Temperature & Humidity Sensor
Your choice of WisBlock Base
Your choice of WisBlock Core
USB Cable
RAK19005 WisBlock Sensor Extension Cable (optional)
Li-Ion/LiPo battery (optional)
Solar charger (optional)
Software
Arduino
Download and install ArduinoIDE .
To add the RAKwireless Core boards on your Arduino Boards Manager, install the RAKwireless Arduino BSP
.
Product Configuration
Hardware Setup
WisBlock can integrate this module which makes it easy to build up an environmental temperature and humidity
data acquisition system.
For more information about the RAK1901, refer to the Datasheet.
The RAK1901 module gives information about:
Environment Temperature
Environment Humidity
RAK1901 module can be connected to the sensor's slot of WisBlock Base to communicate with the WisBlock
Core, as shown in Figure 1. It will work on SLOT A to F. Also, always secure the connection of the WisBlock
module by using compatible screws.

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Figure 1: RAK1901 connection to WisBlock Base
Assembling and Disassembling of WisBlock Modules
Assembling
As shown in Figure 2, the location for Slot A, B, C, and D are properly marked by silkscreen. Follow carefully the
procedure defined in WisBlock Base board 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.

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Figure 2: RAK1901 connection to WisBlock Base
Disassembling
The procedure in disassembling any type of WisBlock modules is the same.
1. First, remove the screws.
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.

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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 the remaining WisBlock Base slots, check on the WisBlock Pin
Mapper tool for possible conflicts. RAK1901 uses I2C communication lines, and it can cause possible
conflict especially on some IO modules.
After all this setup, you can now connect the battery (optional) and USB cable to start programming your WisBlock
Core.
⚠ 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 match the polarity on the WisBlock Base board. Not all batteries have the
same wiring.

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Software Configuration and Example
The RAK1901 is a Temperature & Humidity sensor board that contains the SHTC3 chip. The SHTC3 is a digital
temperature and humidity sensor designed especially for battery-driven high-volume consumer electronics
applications. The device comprises a sensing element and an IC interface which communicates through I2C from
the sensing element to the application.
Initial Test of the RAK1901 WisBlock Module
1. Install the RAKwireless Arduino BSP for WisBlock by using the package_rakwireless_index.json board
installation package. The WisBlock Core should now be available on the Arduino IDE.
2. You need to select first the WisBlock Core you have.
RAK4631 Board
Figure 6: Selecting RAK4631 as WisBlock Core
RAK11200 Board

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Figure 7: Selecting RAK11200 as WisBlock Core
RAK11310 Board
Figure 8: Selecting RAK11310 as WisBlock Core
3. Next, copy the following sample code into your Arduino IDE:
Click Here to View Example Code

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📝 NOTE
If you experience any error in compiling the example sketch, check the updated code for your WisBlock
Core Module that can be found on the RAK1901 WisBlock Example Code Repository and this sample
code in Github will work on all WisBlock Core.
3. Once the example code is open, install the SparkFun SHTC3 library by clicking the yellow highlighted link, as
shown in Figure 9 and Figure 10.
Figure 9: Accessing the library used for RAK1901 Module
Figure 10: Installing the compatible library for RAK1901 Module
4. After successful installation of the library, you can now select the right serial port and upload the code, as shown
in Figure 11 and Figure 12.

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📝 NOTE
If you are using the RAK11200 as your WisBlock Core, the RAK11200 requires the Boot0 pin to be
configured properly first before uploading. If not done properly, uploading the source code to RAK11200
will fail. Check the full details on the RAK11200 Quick Start Guide .
Figure 11: Selecting the correct Serial Port
Figure 12: Uploading the RAK1901 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 13, then your RAK1901 is properly
communicating to the WisBlock core.

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Figure 13: RAK1901 temperature and humidity data logs
Last Updated: 7/29/2022, 10:17:19 PM

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RAK1901 WisBlock Temperature and Humidity
Sensor Datasheet
Overview
Wis BLOCK TEMP & HUMI
Figure 1: RAK1901 WisBlock Sensor
Description
RAK1901 is a WisBlock Sensor that extends the WisBlock system with a Sensirion SHTC3 temperature and
humidity sensor. A ready-to-use SW library and tutorial make it easy to build up an environmental temperature and
humidity data acquisition system.
Features
Temperature sensor accuracy: ±2.0 °C
Temperature range: -40 °C to +125 °C
Humidity sensor accuracy:±2.0% RH
Humidity range:0 to 100%
Voltage Supply: 3.3 V
Current Consumption: 0.3 uA to 270 uA
Chipset: Sensirion SHTC3
Module size: 10 x 10 mm
Specifications
Overview
Mounting
Figure 1 shows the mounting mechanism of the RAK1901 module on a WisBlock Base board. The RAK1901
module can be mounted on the slots: A, B, C, D, E, & F.

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Figure 2: RAK1901 WisBlock Sensor Mounting
Hardware
The hardware specification is categorized into six parts. It shows the chipset of the module and discusses the
pinouts, sensors, and the corresponding functions and diagrams. It also covers the electrical and mechanical
parameters that include the tabular data of the functionalities and standard values of the RAK1901 WisBlock
Temperature and Humidity Sensor.
Chipset
Pin Definition
The RAK1901 WisBlock Temperature and Humidity Sensor comprises a standard WisBlock connector. The
WisBlock connector allows the RAK1901 module to be mounted to a WisBlock Base board. The pin order of the
connector and the pinout definition is shown in Figure 2.
Figure 3: RAK1901 WisBlock Sensor Pinout Diagram
📝 NOTE:
Only the I2C related pins, VDD and GND are connected to this module.
If a 24-pin WisBlock Sensor connector is used, the IO used for the output pulse depends on what slot the module
is plugged in. The following table shows the default IO used for different slots:
Vendor Part number
Sensirion SHTC3

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Sensors
Temperature Sensor
Humidity Sensor
Electrical Characteristics
Recommended Operating Conditions
SLOT A SLOTB SLOT C SLOT D SLOT E SLOT F
WB_IO1 WB_IO2 WB_IO3 WB_IO5 WB_IO4 WB_IO6
Parameter Conditions Value Units
Accuracy Tolerance Typ. ±0.2 °C
Repeatability - 0.1 °C
Resolution - 0.01 °C
Specified Range - -40 to +125 °C
Response Time τ 63% <5 to 30 s
Long-term Drift Typ. <0.2 °C/y
Parameter Conditions Value Units
Accuracy Tolerance Typ. ±2.0 %RH
Repeatability - 0.1 %RH
Resolution - 0.01 %RH
Hysteresis - ±1 %RH
Specified Range extended 0 to 100 %RH
Response Time τ 63% 8 s
Long-term Drift Typ. <0.25 %RH/y

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Mechanical Characteristics
Board Dimensions
Figure 3 shows the dimensions and the mechanic drawing of the RAK1901 module.
Figure 4: RAK1901 WisBlock Sensor Mechanic Drawing
WisConnector PCB Layout
Symbol Description Min Nom. Max Unit
VDD Power supply for the module 1.6 3.3 3.6 V
Isleep Sleep current - 0.3 - uA
IDD Measure current (normal mode) - 430 uA
IDD Measure current (low-power mode) - 270 - uA

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Figure 5: WisConnector PCB footprint and recommendations
Schematic Diagram
Figure 5 shows the schematic of the RAK1901 module.
Figure 6: RAK1901 WisBlock Sensor schematics
Last Updated: 7/29/2022, 10:17:19 PM