Smart Water Meter Application Demo

Overview

The Smart Water Meter Application Demo addresses the limitations of mechanical water meters in terms of accuracy, longevity, and monitoring. The demo is designed to assist utility companies, water providers, and residential consumers in improving water management, reducing operational costs, and increasing efficiency.

The EV-FLOWMETER-ARDZ, an advanced and efficient solution for flow metering, allows the accurate measurement of flow velocity and mass flow rate. This sensor node is used with the MAX32670-SX-ARDZ Base Board, enabling continuous monitoring through low-power and long-range proprietary radio communication. The base board’s custom GUI provides the user with a real-time, comprehensive summary of their water consumption.

The demo showcases the capability of EV-FLOWMETER-ARDZ as a smart water meter when combined with the MAX32670-SX-ARDZ, highlighting its suitability for utility and industrial applications.

To learn more about the reference designs, refer to EV-FLOWMETER-ARDZ and MAX32670-SX-ARDZ.

Demo Requirements

Hardware Requirements

• Microcontroller/Sensors

  • EV-FLOWMETER-ARDZ (2x)

  • MAX32670-SX-ARDZ (2x)

• Gateway Essentials

  • Raspberry Pi 4

  • Raspberry Pi 4 Power Supply Adapter

  • RAK5146 PiHAT

  • RAK5146 SPI Module

  • Long Range Antenna

  • LAN Cable

  • Micro SD Card

  • Spacer Bolt (4x)

  • Screw (6x)

• Microcontroller/Sensor Setup

  • MAX32625PICO Rapid Development Platform with 10-pin ribbon cable

  • CR123A Battery or any equivalent external DC power supply (+3 V to +4.7 V) (2x)

  • Micro USB-to-USB Cable

• Environment Setup

  • CN0508 Benchtop Power Supply

  • Flow Transducer with Pipe (2x)

  • Acrylic Water Container

  • Water Pump System

  • Water

Software Requirements

• Host PC with administrator access

  • Windows 10 OS or later

  • Microsoft .Net Framework 4.6.2

  • 1920 by 1080 or greater screen resolution (recommended)

• Downloaded and installed:

  • MAX32625PICO Firmware Image for MAX32670

  • AD-MAX32WISE-SLZ Firmware (Rel1.0.0)

  • ADI Wireless Sensor Hub Standalone Software for Flowmeter Application

  • UART serial monitor

    • This demo uses Real Term serial monitor, but other UART serial terminals may also be used.

  • Balena Etcher image writing tool

  • ChirpStack Gateway OS

Demo Setup

Block Diagram

The block diagram of the overall setup is shown below.

Hardware Setup

This section describes the hardware setup of the demo divided into three phases: node board assembly, gateway assembly, and environment assembly

Sensor board assembly involves connecting the EV-FLOWMETER-ARDZ to the MAX32670-SX-ARDZ. This phase is to be repeated for each sensor board. Gateway assembly involves setting up the RAK5146 PiHAT and the Raspberry Pi 4 as the concentrator hardware, allowing data transmission from the sensor boards to the host PC. Lastly, environment assembly involves building the setup that will simulate water flow across pipes.

Sensor Board Assembly

For the needed components for this phase, see Microcontroller/Sensors and Microcontroller/Sensor Setup under Hardware Requirements.

1. Insert one CR123A battery (3 V to 4.7 V) into the battery holder (BT1) of the MAX32670-SX-ARDZ Base Board.

   

   To check for the battery polarity in the BT1 connector, refer to the figure above (right). The DS3 LED will light up indicating that you have inserted the battery correctly and that power is provided in the base board.

2. Connect the EV-FLOWMETER-ARDZ Sensor Node to the MAX32670-SX-ARDZ Base Board by aligning the corresponding Arduino headers on each board.

   

3. Connect the MAX32625PICO programming adapter to the MAX32670-SX-ARDZ Base Board through the 10-pin ribbon cable.

   Make sure that the MAX32625PICO programming adapter has been flashed with the correct image before connecting it to the MAX32670-SX-ARDZ Base Board. If you do not know how to load the image, follow the instructions below:

   1. Download the firmware image: MAX32625PICO Firmware Image for MAX32670

   2. Do not connect the MAX32625PICO to the MAX32670-SX-ARDZ Base Board yet.

   3. Press the button on the MAX32625PICO. Do not release the button until the MAINTENANCE drive is mounted.

      

   4. While holding the button, connect the MAX32625PICO to the Host PC using the micro USB to USB cable.

   5. Release the button once the MAINTENANCE drive is mounted.

   6. Drag and drop (to the MAINTENANCE drive) the firmware image.

   7. After a few seconds, the MAINTENANCE drive will disappear and be replaced by a drive named DAPLINK. This indicates that the process is complete, and the MAX32625PICO can now be used to flash the firmware of the MAX32670-SX-ARDZ Base Board.

4. Connect the MAX32625PICO programming adapter to the Host PC using the micro USB to USB cable.

   

Note

To set up the firmware of the sensor board, you may proceed to Configuring the Sensor Board under Software Setup. Since this demo uses two sensor boards, repeat all steps of Sensor Board Assembly for the second board.

Gateway Assembly

For the needed components for this phase, see Gateway Essentials under Hardware Requirements.

1. Insert the RAK5146 SPI module into the mPCIe slot on the RAK2287 Pi HAT. Make sure the card fits snugly into the connector.

2. Gently press the SPI module down and fasten it using the screws provided.

   

3. Connect the RAK5146 PiHAT to the Raspberry Pi using the 40-pin connector.

   

4. Connect the Raspberry Pi to the Host PC using the LAN cable.

5. Power on the Raspberry Pi using the Raspberry Pi 4 Power Supply Adapter.

Note

To configure the gateway, you may proceed to Imaging the SD Card with ChirpStack OS and Configuring the Gateway under Software Setup.

Environment Assembly

For the needed components for this phase, see Environment Setup under Hardware Requirements.

Tip

When using the sensor board, a general-purpose ultrasonic flow rate sensor probe can be used with it. An example of a probe is the Flow Transducer with Pipe (Model: HS0003) from Audiowell Sensor Technology.

For temperature measurement, this board supports up to two 2-wire PT1000/500 platinum resistive temperature detectors (RTD).

1. Connect the wires of the Flow Transducer with Pipe and the resistive temperature detector (RTD) to the sensor board.

   

   Follow the connections shown above. Repeat this step for the other sensor board and transducer.

   Warning

   An RTD or a dummy sensor (1.0 kΩ resistor) is required for each terminal in order for the board to run and capture the flow rate.

2. Set up the water container as shown below.

   

   Tip

   The CN0508 75 Watt, Single-Output Benchtop Power Supply is connected to the water pump in order to vary water flow as needed for the demo.

Note

Once the sensor boards, gateway, and environment are all assembled, proceed to Software Setup to configure the sensor boards, gateway, and the application server.

Software Setup

Warning

Before proceeding with the steps listed below. Make sure that all requirements under Software Requirements are met, with all needed software downloaded and installed.

This section describes the software setup of the demo divided into five phases: configuring the sensor board, imaging the SD card with ChirpStack OS, configuring the gateway, setting up a self-hosted application server, and connecting a sensor node to the gateway.

Configuring the sensor board involves uploading the appropriate firmware to the sensor board using the MAX32625PICO programming adapter and obtaining the board’s DevEUI. To prepare the gateway, imaging the SD card with ChirpStack OS involves flashing the ChirpStack Gateway OS to the Raspberry Pi 4’s micro SD card, while configuring the gateway involves creating the gateway through the ChirpStack Network Server.

To configure the GUI, setting up a self-hosted application server involves configuring the Host PC, installing the GUI, and accessing the gateway. Lastly, connecting a sensor node to the gateway involves creating a device for each board and accessing the GUI.

Tip

Visit ADI Long Range Wireless Radio Software User Guide for a more detailed software setup guide.

Configuring the Sensor Board

Note

Make sure you have completed the steps described in Sensor Board Assembly before proceeding with the steps listed below.

This phase will require Real Term serial monitor and AD-MAX32WISE-SLZ Firmware (Rel1.0.0) installed.

1. If AD-MAX32WISE-SLZ Firmware (Rel1.0.0) is already downloaded, extracted, and installed, go to C:\Analog Devices\AD-MAX32WISE-SLZ-Rel1.0.0\Software\ad_max32wise_src\bin\flow.

   The flow folder should contain the BIN, ELF, and HEX file.

   

2. Go to My Computer and search for the DAPLINK drive. Drag and drop (or copy and paste) the .bin firmware file directly into the DAPLINK drive.

   Tip

   To check if the flashing is successful, check the DAPLINK directory and make sure there is no FAIL.TXT file. In case there is, repeat the drag and drop step.

3. Reset the MAX32670-SX-ARDZ Base Board by pressing the S1 reset button.

4. Open the Real Term serial monitor to check if the firmware has been loaded correctly. Make sure to use the following settings:

   • Ports: Take note of the COM port used by checking the Device Manager

   • Baud Rates and Ports: Set to 921600

     

   • Display formatting: Set to ANSI

   • Enable Scrollback: Set to 200.

     

5. Once configured, open the serial monitor by clicking Open on the Port tab.

6. Take note of the DevEUI (64-bit end-device identifier). This will be used later during the gateway setup.

   

   Tip

   To redisplay the DevEUI on the screen, reset the MAX32670-SX-ARDZ Base Board by pressing the S1 button.

Imaging the SD Card with ChirpStack OS

Note

This phase will require Balena Etcher image writing tool installed and ChirpStack Gateway OS downloaded. This phase will also use the micro SD card listed under Gateway Essentials.

1. Run the Balena Etcher image writing tool.

2. Insert the micro SD card into the Host PC.

3. Click Flash from file from the options shown in the interface.

   

4. Navigate to the location where the downloaded ChirpStack Gateway OS is saved.

5. Select target and choose the targeted micro SD card drive.

6. Click Flash to start the burning process of the image in the chosen SD card.

7. Wait until it is done.

   

   Tip

   In case the flashing fails, consult this guide to resolve the issue: Balena Etcher FAQs.

Warning

After the first boot, the gateway might reboot automatically to apply some changes. The full image will set up the PostgreSQL database on its first boot. This could take a couple of minutes and during this time the gateway will be less responsive.

Configuring the Gateway

Note

Make sure you have completed the steps described in Gateway Assembly before proceeding with the steps listed below. Make sure that the Raspberry Pi (powered on) and Host PC are still connected through the LAN cable.

Opening the SSH client

1. Insert the imaged SD card on the designated slot on the Raspberry Pi.

2. Connect the Host PC to ChirpStack WiFi.

   Tip

   When prompted to enter password, use ChirpStackAP (case-sensitive).

3. Open command prompt or terminal on the Host PC.

4. On the terminal, enter:

   ssh admin@192.168.0.1
   

5. SSH connection will ask for the password input. Use below credentials:

   • Username: admin

   • Password: admin

   • StaticIP: 192.168.0.1

6. Once connected, check the assigned ChirpStack IP by typing ifconfig.

   

7. This will show all configs, look for eth0 and save the IP address assigned to it.

   

   Tip

   In this example, the IP assigned is 169.254.117.207. This will be used in Installing the GUI and Accessing the Gateway under Setting up a Self-Hosted Application Server.

8. Open the Raspberry Pi terminal, then enter:

   sudo gateway-config
   

   This will open an SSH client to configure the gateway.

Navigating the SSH client

1. In the main menu, choose Setup concentrator shield.

2. Choose RAK5146 (with GNSS). Click OK.

3. Choose AU915. Click OK.

4. Choose Channels 0 to 7 + 64. Click OK.

5. The concentrator restarts and goes back to the main menu.

6. Quit the main menu.

   Tip

   If you have properly configured the gateway and installed the required SD card image, then you are ready to use the ChirpStack Network Server.

Setting up a Self-Hosted Application Server

Note

Make sure that the Raspberry Pi (powered on) and Host PC are still connected through the LAN cable.

This phase will require ADI Wireless Sensor Hub Standalone Software (Rev 1.0.3) downloaded and extracted.

Configuring the Host PC for the Gateway

1. Access Advanced Firewall settings in your computer.

   

2. Create a new Inbound Rule.

   

3. Configure the Inbound Rule as shown below.

   Step-by-step configuration of a new ChirpStack Inbound Rule:

   

Installing the GUI and Accessing the Gateway

1. Run the ADI Wireless Sensor Hub Standalone Software with administrator privileges. This will start the initialization process and run the process on your PC.

2. Check and save the IP address assigned to the Raspberry Pi gateway. The server will show all connections available; select the IP of the connector you used.

   Tip

   In this example, it is the Apple USB Ethernet Adapter.

   

   This information will be used in Setting up a Local Host URL for the Application Server under Connecting a Sensor Node to the Gateway to integrate data from the gateway to the GUI.

3. Use the assigned ChirpStack IP address saved earlier to access its configuration interface by adding the ChirpStack Port (8080) to the end of IP address. Open a page in the browser using [saved IP address]:8080 as the URL.

   Tip

   In this example, the saved IP address is 169.254.117.207. Hence, the URL would be 169.254.117.207:8080.

   If you haven’t saved the IP address, revisit steps 3 to 7 in Opening the SSH client under Configuring the Gateway.

4. This will open the login page. Enter the same credentials we used to establish an SSH connection with the ChirpStack Gateway.

   

Connecting a Sensor Node to the Gateway

This phase describes how to connect the sensor nodes to ChirpStack and how to validate that it can send data. This process is divided into three sections:

• Creating a device profile

• Enrolling device applications

• Setting up a local host URL for the application server.

Note

At this point, it is assumed that you have a working ChirpStack environment with a connected gateway.

Creating a Device Profile

1. Once you are in the ChirpStack landing page, navigate to the Applications tab.

2. Click Device profiles under the Tenant category.

3. Click on the Add device profile button.

   

4. Answer all required information under the General tab, and then click Submit once done. The following shows the configuration required to add a sensor node:

   Attribute	Configuration
   Name	Enter desired sensor node name
   Region	AU915
   Region Configuration	AU915 (channels 0-7 +64)
   MAC Version	LoRaWAN 1.0.4
   Regional parameters revision	A
   ADR algorithm	Default ADR algorithm (LoRa only)
   Expected uplink interval (sec)	10
   Device-status request frequency (req/day)	8640

Enrolling Device Applications

1. After adding a device, click the Applications option under Tenant.

2. Click on the Add application button.

3. Write the desired Application Name on the space provided. Hit Submit once done.

   

4. Open the Application created and add a device. The following details are also needed:

   • Name: previously defined application name set from the previous steps

   • Device EUI (EUI64): unique serial number of the device

   • Device profile: previously defined device profile set from the previous steps

   Warning

   In naming the devices, you must include a specific keyword (not case-sensitive) to distinguish the sensor nodes shown on the GUI. In this case, the two sensor nodes can be named flow-1 and flow-2 respectively.

   

5. Once done, click Submit. Then, repeat steps 5 and 6 for the other sensor board.

   Tip

   For OTAA devices, confirm that when the device tries to OTAA activate, you see a JoinRequest message followed by a JoinAccept message.

   If you do not see a JoinRequest and JoinAccept, click on the Flush OTAA devices button.

6. Enter the Application key and hit Submit once done.

   

   Tip

   For this demo, the Application key is 2b7e151628aed2a6abf7158809cf4f3c.

   The App Key included in the LoraMAC was used as is for the purpose of evaluation. Users can generate the App Key and add it in the source code on their own.

Setting up a Local Host URL for the Application Server

1. In the Applications tab, select and open WiSe_Sensors.

2. Inside the ADI_SENSOR_NODE application, navigate to the Integrations tab.

   

3. In the Integrations tab, select the edit button in the HTTP Configuration section.

4. Change the Event Endpoint URL to the IP of the adapter your gateway is connected.

   

   Tip

   In this example, it is the IP of the Apple Network Adapter, http://169.254.178.157:5050/api/data/post.

   If you haven’t saved the IP address, revisit steps 1 to 2 in Installing the GUI and Accessing the Gateway under Setting up a Self-Hosted Application Server.

5. After updating the HTTP Integration endpoint URL, submit the changes by pressing Submit.

6. A pop-up message will appear saying HTTP Integration updated.

   

7. Open your browser and enter the URL http://localhost:5050. Now you’ll be able to see and monitor your active nodes.

Actual Demo

Working Setup

Custom GUI

The custom GUI for this demo highlights the EV-FLOWMETER-ARDZ as a smart water meter with two main features: - Water bill computation - Leakage detection

Resources

• MAX32670-SX-ARDZ Base Board

• EV-FLOWMETER-ARDZ Sensor for Flow Rate Metering

Design and Integration Files

Download

AD-MAX32SXWISE-SL Design Support Package

• Schematic

• Bill of Materials

• Layout

• Fabrication Files

Help and Support

For questions and more information about this product, connect with us through the Analog Devices Engineer Zone.

EngineerZone Support Community