A simple example that shows how to communicate with a w3bstream node from an Arduino Nano 33 IoT or an ESP32.
The sketch will detect when a button was pressed and send an event to a w3bstream node.
First clone this project usng git, or download the contents as zip and extract the zip contents to your machine.
Open the secrets.h file and replace the definitions to suit your application.
Make sure that PlatformIO is installed and in your path. You can check if it is by running pio --version in your terminal. It will return your platformio version if it is installed.
Ensure that your device is connected to a USB port and recognized by your pc. If your PC doesn't recognize the device, then check that you have the proper driver installed for your board.
On a terminal, change directory to the folder where the platformio.ini file is located.
If you just want to compile the sketch, run the following command:
pio run -e <esp32 or nano_33_iot>
If you want to compile, run and monitor the sketch over a serial port, run the following command:
pio run -e <esp32 or nano_33_iot> -t upload -t monitor
Install the required Arduino core for the board you are using (Nano 33 IoT or ESP32).
Then you need to install some library dependencies through the library manager.
The following libraries are required:
- PubSubClient for MQTT.
- Arduino_JSON for JSON serializing.
- NTPClient for getting the current unixtime.
Additionally, for Nano 33 IoT, the following libraries are also required:
- WiFiNINA for WiFi.
- ArduinoHttpClient for HTTP.
Once done with the previous steps, click the Upload button to compile and flash the sketch.
You can then open the serial monitor to see the serial port log.
The sketch detects when the pin BUTTON_PIN has been pressed. By default, the pin is configured as an input with a pullup resistor.
In the default state, this pin must be wired to GND. You can use a dupont wire for this.
Whenever you want to trigger an event, disconnect the pin from GND an reconnect it.
The serial monitor will print a log indicating whther the event has been sent successfully or if there has been an error.
If the event was sent successfully, you should now be able to see it in your w3bstream node.
If your particular board has a button or switch, you can change the value of BUTTON_PIN to suit your board.
Depending on how the button is wired, you may also need to change the pin from PULLUP to PULLDOWN and also modify isPressed() to return true when the pin value is LOW.