Now that you've installed WipperSnapper on your board - let's learn how to use Adafruit IO to interact with it!
There's a large number of components (physical parts like buttons, switches, sensors, and actuators) supported by the WipperSnapper firmware. This page will get you started with the core concepts of WipperSnapper and Adafruit IO.
One of the first programs you typically write to get used to embedded programming is a sketch that repeatably blinks an LED. IoT projects are wireless, so after completing this section, you'll be able to turn on (or off) the LED built into your Feather from anywhere in the world.
Navigate to the device page, io.adafruit.com/wippersnapper. You should see the Feather you just connected to Adafruit IO listed on this page.
Verify that your Feather is online and ready to communicate with Adafruit IO by checking that the device tile says Online in green text.
If the Feather appears offline on the website but was previously connected, press the Reset (RST) button to force the board to reboot.
Once verified that the board is online, click the device tile to navigate to the board's page.
Add a new component to your Feather by clicking the + button or the + New Component button on the board page.
The Component Picker lists all the available components, sensors, and parts, which can be used with the WipperSnapper firmware. Your Feather board already has a LED built-in, so there's no wiring for you to configure.
Click the LED component.
Feathers contain GPIO pins that can be configured either as an input or an output. The "Create LED Component" screen tells WipperSnapper to configure a general-purpose output pin connected to the LED on your Feather as a digital output so you can turn the LED on or off.
The Feather ESP32-S2 has a built-in LED located at pin D13. Select this pin as the LED Pin and click Create Component
Behind the scenes, Adafruit IO sends send a command to your board running WipperSnapper telling it to configure the GPIO pin as a digital output. Your Feather's page shows the new LED component.
From the page, toggle the LED component by clicking the toggle switch. This should turn your Feather's built-in LED on or off.
You can also configure a board running WipperSnapper to wirelessly read data from standard input buttons, switches, or digital sensors, and send the value to Adafruit IO.
Let's wire up a push button to your Feather and configure it with Adafruit IO to publish a value to Adafruit IO when the button has been pressed or depressed.
We'll be using the Feather's internal pull-up resistors instead of a physical resistor.
On the board's page, add a new component to your Feather by clicking the + button or the + New Component button.
From the component picker, select the Push Button.
The next screen presents you with options for configuring the push button. Start by selecting the Feather's digital pin you connected to the push button.
The Return Interval dictates how frequently the value of the push-button will be sent from the Feather to Adafruit IO. For this example, the push-button's value should only be sent when it's pressed.
Select On Change
Finally, check the Specify Pin Pull Direction checkbox and select Pull Up to turn on the Feather's internal pullup resistor.
Make sure the form's settings look like the following screenshot. Then, click Create Component.
Adafruit IO should send a command to your board (running WipperSnapper), telling it to configure the GPIO pin you selected to behave as a digital input pin and to enable it to pull up the internal resistor. Your Feather's page should also show the new push-button component.
Press the button to change the value of the push button component on Adafruit IO.
Inter-Integrated Circuit, aka I2C, is a two-wire protocol for connecting sensors and "devices" to a microcontroller. A large number of sensors, including the ones sold by Adafruit, use I2C to communicate.
Typically, using I2C with a microcontroller involves programming. Adafruit IO lets you configure a microcontroller to read data from an I2C sensor and publish that data to the internet without writing code.
The WipperSnapper firmware supports a number of I2C sensors, viewable in list format here. If you do not see the I2C sensor you're attempting to use with WipperSnapper - we have a guide on adding a component to Adafruit IO WipperSnapper here.
The process for adding an I2C component to your board running WipperSnapper is similar to most sensors. For this section, we're using the Adafruit AHT20, an inexpensive sensor that can read ambient temperature and humidity.
First, wire up an AHT20 sensor to your board exactly as follows. Here is an example of the AHT20 wired to a Feather using I2C with a STEMMA QT cable (no soldering required).
Board 3V to sensor VIN (red wire on STEMMA QT)
Board GND to sensor GND (black wire on STEMMA QT)
Board SCL to sensor SCL (yellow wire on STEMMA QT)
- Board SDA to sensor SDA (blue wire on STEMMA QT)
Scan I2C Bus
First, ensure that you've correctly wired the AHT20 sensor to your Feather by performing an I2C scan to detect the I2C device on the bus.
On the upper left-hand corner of the board page, click Start I2C Scan.
- If you do not see this button, double-check that your Feather shows as Online.
You should see a new pop-up showing a list of the I2C addresses detected by an I2C scan. If wired correctly, the AHT20's default I2C address of
0x38 appear in the I2C scan list.
First, double-check the connection and/or wiring between the sensor and the board.
Then, reset the board and let it re-connect to Adafruit IO WipperSnapper.
Create the Sensor Component
Now that you know the sensor can be detected by the Feather, it's time to configure and create the sensor on Adafruit IO.
On the device page, add a new component to your Feather by clicking the + button or the + New Component button.
The Component Picker lists all the available components, sensors, and parts that can be used with WipperSnapper.
Under the I2C Components header, click AHT20.
On the component configuration page, the AHT20's I2C sensor address should be listed along with the sensor's settings.
The AHT20 sensor can measure ambient temperature and relative humidity. This page has individual options for reading the ambient temperature, in either degree Celsius or degree Fahrenheit, and the relative humidity. You may select the readings which are appropriate to your application and region.
The Send Every option is specific to each sensor measurement. This option will tell the Feather how often it should read from the AHT20 sensor and send the data to Adafruit IO. Measurements can range from every 30 seconds to every 24 hours.
For this example, set the Send Every interval for both seconds to Every 30 seconds and click Create Component.
The board page should now show the AHT20 component you created.
After the interval you configured elapses, WipperSnapper automatically reads values from the sensor and sends them to Adafruit IO.
Want to learn more about Adafruit IO WipperSnapper? We have more complex projects on the Adafruit Learning System.