TWELITE SPOT

• 1: Getting Started
• 2: Basics of Firmware Development with ESP32
• 3: Receiving Data from a TWELITE Child
• 4: Related Information

The wireless LAN gateway TWELITE SPOT is a product that combines the low-power wireless microcontroller module TWELITE with the wireless LAN microcontroller module ESP32. By developing firmware for the ESP32, you can integrate the TWELITE network with Wi-Fi networks.

For product specifications, please refer to the Datasheet.

Expanding Possibilities with TWELITE and ESP32

TWELITE SPOT is a product that combines the compact, low-power, and pairing-free TWELITE series—which allows many devices to be used simultaneously—with the wireless LAN microcontroller module ESP32.

For customers who frequently use the TWELITE series

Settings such as frequency channels are changed via the ESP32. Unlike other products, you cannot use the interactive mode from the 7P interface. Configuration is done using the TWELITE-specific Arduino library provided for ESP32.

Note: The 7P interface on the TWELITE side is only used for updating the SPOT-specific parent application.

By developing firmware for the ESP32, you can implement systems such as the following:

Local Server	Local Gateway	IoT Gateway
Share data from TWELITE Child devices within the LAN	Use data from TWELITE Child devices within the LAN	Use data from TWELITE Child devices in the cloud

Local Server

The ESP32 is used as a server. For example, you can display acceleration data measured by a TWELITE CUE on a smartphone or operate the output ports of a TWELITE DIP from a smartphone.

Sample sketch

• Display data on the hosted page: spot-server.ino

Local Gateway

The ESP32 connects to the LAN. For example, data sent from TWELITE ARIA devices installed throughout a building can be received by TWELITE SPOT devices on each floor, aggregating temperature and humidity data from all floors on a server within the LAN.

Sample sketch

• Send to WebSocket server: spot-router.ino

IoT Gateway

The ESP32 connects to the Internet. For example, by attaching a TWELITE CUE and a magnet to a door, you can detect on the cloud whether the door remains open based on the acquired door open/close status.

Sample sketches

• Using REST API: spot-httpbin.ino
• Using Google Spreadsheets: spot-google-sheets.ino

Development with Arduino IDE and Dedicated Library

To build a system using TWELITE SPOT, you need to develop firmware for the ESP32.

Arduino IDE can be used for firmware development on the ESP32.

There is a vast amount of information online about firmware development using Arduino IDE.

For example, try searching for esp32 arduino.

The MWings library, distributed via the Arduino Library Manager, makes it easy to receive packets from TWELITE Child devices and send commands to them.

The MWings library can also be used with the Arduino UNO R4 series.

Flow of the Start Guide

This start guide covers verifying TWELITE SPOT operation, setting up the ESP32 development environment, creating simple sketches, and writing them.

1. Verify TWELITE SPOT Operation

Get Started

Contents

Using the pre-installed app on TWELITE SPOT, view acceleration sensor wireless tag TWELITE CUE data on a smartphone.

Required Items

TWELITE SPOT	TWELITE CUE
TWELITE Parent	TWELITE Child

2. Perform Hello World on ESP32

Basics of Firmware Development Using ESP32

Contents

Set up the development environment, create and write a Hello World sketch, and verify operation.

Required Items

TWELITE SPOT	TWELITE R3
TWELITE SPOT device to write firmware	USB adapter to connect PC and TWELITE SPOT

3. Acquire Data from TWELITE CUE

Communication with TWELITE

Contents

Output acceleration data from TWELITE CUE via ESP32.

Required Items

TWELITE SPOT	TWELITE CUE	TWELITE R3
TWELITE SPOT device to write firmware	TWELITE Child device to communicate with TWELITE SPOT	USB adapter to connect PC and TWELITE SPOT

The start guide uses TWELITE CUE as the TWELITE Child device, but the content can also be applied to other TWELITE series such as the temperature and humidity sensor wireless tag TWELITE ARIA.

The start guide uses third-party open-source software.

We cannot provide detailed instructions on the use of third-party software. We also assume no responsibility for any damages resulting from the use of third-party software.

1 - Getting Started

Here, TWELITE SPOT functions as a wireless LAN access point.

What You Need

• Wireless LAN Gateway TWELITE SPOT
  • USB-C cable for power
  • USB AC adapter (capable of supplying 1A or more)
• Acceleration Sensor Wireless Tag TWELITE CUE (If you do not have one, please purchase it 👉 Retailers List)
• 📱 Smartphone

Confirm TWELITE SPOT Operation

1. Power On the Device ⚡

Connect the USB-C cable to the side of TWELITE SPOT and supply power from the USB AC adapter.

2. Power On TWELITE CUE ⚡

Insert a CR2032 coin battery into TWELITE CUE. It will start operating immediately.

3. Connect Your Smartphone 📱

Connect your smartphone to the Wi-Fi network TWELITE SPOT (XXXX) from the Wi-Fi settings.

4. Open a Web Browser 🌐

Open a web browser on your smartphone and access spot.local.

You will see a screen like the following.

5. Open the CUE Viewer 📈

Tap on CUE Viewer to open the CUE viewer screen.

You will see a screen like the following.

2 - Basics of Firmware Development with ESP32

What You Need

• Wireless LAN Gateway TWELITE SPOT
  • USB-C cable for power
  • USB AC adapter (capable of supplying 1A or more)
• USB Adapter TWELITE R3 (Please purchase if you do not have one 👉 List of retailers)
  • USB-C cable for communication
• 💻 Computer

Setting Up the Environment

1. Install the IDE 🚛

If you have not installed Arduino IDE 1.x on your computer, please download the Legacy IDE (1.8.X) from the Arduino official download page and install it.

2. Install the Toolchain 🚚

If you have not installed Arduino core for the ESP32 in Arduino IDE 1.x, add the following URL to the Board Manager URLs and install the esp32 board definition.

https://espressif.github.io/arduino-esp32/package_esp32_index.json

3. Configure the Board Settings ⚙️

Configure Arduino core for the ESP32 to match TWELITE SPOT.

Select the Board Type

From the toolbar, select Tools -> Board -> ESP32 Arduino -> ESP32 Dev Module.

Configure Board Settings

Configure as shown in the figure below.

Prepare TWELITE SPOT

1. Remove the Cover ⛏️

Remove the cover on the top of the TWELITE SPOT case.

Switches and connectors will be exposed.

2. Connect TWELITE R3 / R2 🔌

Connect TWELITE R3 / R2 to the 7P interface for ESP32 (marked ESP32).

3. Connect USB-C Power ⚡

Supply 5V power to the USB-C connector on the side.

Run the Sketch

In Arduino, programs/projects are called sketches.

1. Create the Sketch 👨‍💻

Create a Hello World sketch that outputs a string from ESP32 to the serial port and displays it on the Arduino IDE serial monitor.

Start Arduino IDE and enter the following code.

void setup() {
  Serial.begin(115200);
  Serial.println("Hello, World!");
}

void loop() {
}

The contents of setup() run only once at startup. The contents of loop() run repeatedly without end.

On the second line, the baud rate (communication speed) of the serial port is set to 115200bps.

  Serial.begin(115200);

On the third line, the string "Hello, World!" is output to the serial port.

  Serial.println("Hello, World!");

2. Write the Sketch ⚒️

Select the Serial Port

From the Tools -> Serial Port menu, select the port for the connected device (TWELITE R series).

Start ESP32

Start ESP32 in programming mode.

Press the ESP32 reset switch EN(RST) and the ESP32 boot switch BOOT, then release them in the order EN(RST) -> BOOT.

Write the Sketch

Click the Upload button on the Arduino IDE toolbar.

3. Open the Serial Monitor 🖥️

Open the Screen

Click the Serial Monitor button at the top right of Arduino IDE.

Configure Settings

Set the baud rate at the bottom right of the serial monitor screen to 115200.

4. Run the Sketch 🚀

Restart ESP32

After writing is complete, press and release the ESP32 reset switch EN(RST) on TWELITE SPOT to reset ESP32.

Check the Serial Monitor

If the following string is displayed on the serial monitor, it was successful.

Hello, World!

3 - Receiving Data from a TWELITE Child

What You Need

• Wireless LAN Gateway TWELITE SPOT
  • USB-C cable for power
  • USB AC adapter (capable of supplying 1A or more)
• Acceleration Sensor Wireless Tag TWELITE CUE (If you do not have one, please purchase 👉 List of Retailers)
  • CR2032 coin battery
• USB Adapter TWELITE R3 (If you do not have one, please purchase 👉 List of Retailers)
  • USB-C cable for communication
• 💻 Computer

Setting Up the Environment

1. Install the Development Environment 🚛

If you have not set up the environment described in Basic Firmware Development Using ESP32, please do so first.

2. Configure the Board Settings ⚙️

Set the board type to ESP32 Dev Module and configure as shown below.

3. Install the Library 🚚

Install the MWings Library required to use TWELITE from ESP32.

Open Sketch -> Include Library -> Manage Libraries…

Type MWings in the search box and install MWings.

Prepare the TWELITE SPOT

1. Remove the Cover ⛏️

Remove the top cover of the TWELITE SPOT case.

2. Connect the Cables 🔌

Connect TWELITE R3 / R2 to the ESP32 7P interface labeled ESP32, then supply 5V power to the USB-C connector on the side.

Run the Sketch First

1. Open the Sample 📂

Launch Arduino IDE, then select File -> Examples -> MWings -> monitor_spot_app_cue.

2. Select the Serial Port ⚙️

From the Tools -> Port menu, select the port of the connected device (TWELITE R series).

3. Start the ESP32 👇

Start ESP32 in programming mode.

Press the reset switch EN(RST) and the ESP32 boot switch BOOT, then release in the order EN(RST) -> BOOT.

4. Write the Sketch ⚒️

Click the Upload button at the top of the Arduino IDE.

5. Open the Serial Monitor 🖥️

Open the Window

Click the Serial Monitor button at the top right of the Arduino IDE.

Configure

Set the serial monitor baud rate to 115200.

6. Restart ESP32 🚀

After writing is complete, press and release the ESP32 reset switch EN(RST) on the TWELITE SPOT to reset the ESP32.

7. Confirm Startup 💬

If the following string appears on the serial monitor, startup was successful.

Monitor example for TWELITE SPOT: App_CUE (CUE Mode)

Monitor example for TWELITE SPOT: App_ARIA (ARIA Mode)

8. Start TWELITE CUE ⚡

Insert a CR2032 coin battery into the TWELITE CUE. It will start operating immediately.

9. Confirm Reception 💬

If the following string appears on the serial monitor, data reception from TWELITE CUE was successful.

Packet Number:     #3
Source Logical ID: 0x1
LQI:               147
Supply Voltage:    3310 mV
Accel Event:       Dice (1)
Accel X Axis [0]:  72 mG
Accel Y Axis [0]:  -64 mG
Accel Z Axis [0]:  1000 mG
Magnet State:      Leaving or Not found

Sketch Explanation

Here is a brief explanation of the sample sketch (monitor_spot_app_cue.ino).

Including the Library

Line 4 includes the MWings library you installed earlier.

#include "MWings.h"

Defining Pin Numbers

Lines 6-8 define the pin numbers.

const int RST_PIN = 5;
const int PRG_PIN = 4;
const int LED_PIN = 18;

Defining TWELITE Settings

Lines 10-11 define the settings applied to the TWELITE Parent installed in TWELITE SPOT.

const uint8_t TWE_CHANNEL = 18;
const uint32_t TWE_APP_ID = 0x67720102;

Serial Port Setup

Lines 19-21 initialize the serial ports and output the startup message to the serial monitor.

  Serial.begin(115200);
  Serial.println("Monitor example for TWELITE SPOT: App_CUE (CUE Mode)");
  Serial2.begin(115200);

Serial is used for communication with the Arduino IDE serial monitor. The baud rate is set to 115200 bps to match the serial monitor settings.

Serial2 is used for communication with the TWELITE Parent installed on TWELITE SPOT. This is also set to 115200 bps to match the Parent’s initial settings.

TWELITE Initialization

Lines 24-26 call Twelite.begin() to configure and start the TWELITE Parent on TWELITE SPOT.

    Twelite.begin(Serial2,
                      LED_PIN, RST_PIN, PRG_PIN,
                      TWE_CHANNEL, TWE_APP_ID);

Registering Packet Reception Event

Lines 29-49 call Twelite.on() to register the processing to be done when data is received from the TWELITE CUE.

Here, the received packet content is output to the serial monitor.

    Twelite.on([](const ParsedAppCuePacket& packet) {
        Serial.println("");
        Serial.print("Packet Number:     #");
        Serial.println(packet.u16SequenceNumber, DEC);
        Serial.print("Source Logical ID: 0x");
        Serial.println(packet.u8SourceLogicalId, HEX);
        Serial.print("LQI:               ");
        Serial.println(packet.u8Lqi, DEC);
        Serial.print("Supply Voltage:    ");
        Serial.print(packet.u16SupplyVoltage, DEC); Serial.println(" mV");
        Serial.print("Accel Event:       ");
        printAccelEvent(packet.u8AccelEvent);
        Serial.print("Accel X Axis [0]:  ");
        Serial.print(packet.i16SamplesX[0], DEC); Serial.println(" mG");
        Serial.print("Accel Y Axis [0]:  ");
        Serial.print(packet.i16SamplesY[0], DEC); Serial.println(" mG");
        Serial.print("Accel Z Axis [0]:  ");
        Serial.print(packet.i16SamplesZ[0], DEC); Serial.println(" mG");
        Serial.print("Magnet State:      ");
        printMagnetState(packet.u8MagnetState, packet.bMagnetStateChanged);
    });

This event is called only when a packet is received from the TWELITE CUE.

The received packet content is stored in the argument packet of type ParsedAppCuePacket.

packet contains the following data (the bold data are used in the code above).

Twelite.on([](const ParsedAppAriaPacket& packet) {
    // Handle packet...
});

Updating TWELITE Data

Line 55 calls Twelite.update().

    Twelite.update();

Twelite.update() reads packet data (ModBus ASCII format) from the TWELITE Parent one byte at a time.

4 - Related Information

MWings Library

• GitHub Repository: monowireless/mwings_arduino
• MWings API Reference: TWELITE Wings API for 32-bit Arduinos

TWELITE Product Datasheets

• TWELITE SPOT
• TWELITE BLUE
• TWELITE R3

TWELITE SPOT Manuals

Sketch Explanations

• Without Wi-Fi
  • Extremely Simple! Standard App for Data Acquisition and Operation
  • Data Acquisition for Cue App
  • Data Acquisition for Aria App
• With Wi-Fi
  • Pre-installed Sketch
  • Relay via WebSocket
  • Using REST API
  • Using Google Spreadsheets
  • Graph Display via ThingSpeak

Others

• Installation Methods Considering Wireless Performance
• Setting Up Development Environment with Arduino IDE 1.x
• How to Write Sketches to ESP32
• How to Write Files to ESP32
• How to Write with Specified Partition Table on ESP32

External Links

Arduino

• Official Site: Arduino - Home
  • API Reference: Arduino Reference - Arduino Reference
  • Coding Style Guide: Arduino Style Guide for Creating Libraries | Arduino Documentation
  • Official JSON Library: arduino-libraries/Arduino_JSON: Official JSON Library for Arduino
  • Official NTP Library: arduino-libraries/NTPClient: Connect to a NTP server

ESP32

• Product Information: ESP32 Wi-Fi & Bluetooth MCU I Espressif Systems
  • Datasheet: esp32_datasheet_en.pdf
• Arduino Toolchain: espressif/arduino-esp32: Arduino core for the ESP32
  • Getting Started Guide: Getting Started — Arduino-ESP32 documentation
  • Installation Guide: Installing — Arduino-ESP32 documentation
  • API Reference: Libraries — Arduino-ESP32 documentation
    • Wi-Fi API: Wi-Fi API — Arduino-ESP32 documentation
  • Tutorials: Tutorials — Arduino-ESP32 documentation
  • Troubleshooting: Troubleshooting — Arduino-ESP32 documentation
• ESP-IDF: espressif/esp-idf: Espressif IoT Development Framework
  • Documentation: ESP-IDF Programming Guide - ESP32
    • Multitasking and Queue Related: FreeRTOS (ESP-IDF) - ESP32

Community

Libraries

• Asynchronous TCP: me-no-dev/AsyncTCP: Async TCP Library for ESP32
• Asynchronous Web Server: me-no-dev/ESPAsyncWebServer: Async Web Server for ESP8266 and ESP32
• WebSocket: Links2004/arduinoWebSockets: arduinoWebSockets
• Google Spreadsheets: mobizt/ESP-Google-Sheet-Client: Arduino Google Sheet REST client library
• Date and Time: PaulStoffregen/Time: Time library for Arduino
• Seeed 96x96 / 128x128 OLED: Seeed-Studio/OLED_Display_96X96: Seeed OLED Display 96*96 library

Plugins

• File Writing: me-no-dev/arduino-esp32fs-plugin: Arduino plugin for uploading files to ESP32 file system
• Stack Trace: me-no-dev/EspExceptionDecoder: Exception Stack Trace Decoder for ESP8266 and ESP32