Next we'll get our WiFi and Adafruit IO information onto our Matrix Panel.
CircuitPython works with WiFi-capable boards to enable you to make projects that have network connectivity. This means working with various passwords and API keys. As of CircuitPython 8, there is support for a settings.toml file. This is a file that is stored on your CIRCUITPY drive, that contains all of your secret network information, such as your SSID, SSID password and any API keys for IoT services. It is designed to separate your sensitive information from your code.py file so you are able to share your code without sharing your credentials.
CircuitPython previously used a secrets.py file for this purpose. The settings.toml file is quite similar.
CircuitPython settings.toml File
This section will provide a couple of examples of what your settings.toml file should look like, specifically for CircuitPython WiFi projects in general.
The most minimal settings.toml file must contain your WiFi SSID and password, as that is the minimum required to connect to WiFi. Copy this example, paste it into your settings.toml, and update:
your_wifi_ssid
your_wifi_password
CIRCUITPY_WIFI_SSID = "your_wifi_ssid" CIRCUITPY_WIFI_PASSWORD = "your_wifi_password"
Many CircuitPython network-connected projects on the Adafruit Learn System involve using Adafruit IO. For these projects, you must also include your Adafruit IO username and key. Copy the following example, paste it into your settings.toml file, and update:
your_wifi_ssid
your_wifi_password
your_aio_username
your_aio_key
CIRCUITPY_WIFI_SSID = "your_wifi_ssid" CIRCUITPY_WIFI_PASSWORD = "your_wifi_password" AIO_USERNAME = "your_aio_username" AIO_KEY = "your_aio_key"
Some projects use different variable names for the entries in the settings.toml file. For example, a project might use AIO_ID
in the place of AIO_USERNAME
. If you run into connectivity issues, one of the first things to check is that the names in the settings.toml file match the names in the code.
Here is an example settings.toml file.
# Comments are supported CIRCUITPY_WIFI_SSID = "guest wifi" CIRCUITPY_WIFI_PASSWORD = "guessable" CIRCUITPY_WEB_API_PORT = 80 CIRCUITPY_WEB_API_PASSWORD = "passw0rd" test_variable = "this is a test" thumbs_up = "\U0001f44d"
In a settings.toml file, it's important to keep these factors in mind:
- Strings are wrapped in double quotes; ex:
"your-string-here"
- Integers are not quoted and may be written in decimal with optional sign (
+1
,-1
,1000
) or hexadecimal (0xabcd
).- Floats, octal (
0o567
) and binary (0b11011
) are not supported.
- Floats, octal (
- Use
\u
escapes for weird characters,\x
and\ooo
escapes are not available in .toml files- Example:
\U0001f44d
for đź‘Ť (thumbs up emoji) and\u20ac
for € (EUR sign)
- Example:
- Unicode emoji, and non-ASCII characters, stand for themselves as long as you're careful to save in "UTF-8 without BOM" format
Â
Â
When your settings.toml file is ready, you can save it in your text editor with the .toml extension.
In your code.py file, you'll need to import
the os
library to access the settings.toml file. Your settings are accessed with the os.getenv()
function. You'll pass your settings entry to the function to import it into the code.py file.
import os print(os.getenv("test_variable"))
In the upcoming CircuitPython WiFi examples, you'll see how the settings.toml file is used for connecting to your SSID and accessing your API keys.
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