Meadow has a robust configuration framework that allows you to adjust settings at build-time and deploy them with an app.

OS/Device Configuration and Application Configuration

Meadow.OS support the following configuration sets:

  • OS & Device Configuration - Specified in the meadow.config.yaml file. Includes general board and system configuration settings.
  • WiFi Network Credentials - Specified in the wifi.config.yaml. Specifies WiFi access point and password configuration.
  • Application Configuration - Specified in app.config.yaml. This functionality is coming soon.

These files are optional and the default values (shown below) will be used if the particular file is missing from the file system.

Must Set Copy to Output Directory Build Action

In order to make sure these files are deployed to the device, they must be set to Copy to Output Directory in the project.

Meadow.OS and Device Configuration (meadow.config.yaml)

Includes OS and device level settings such as device name, default network behavior, and network settings.

Consider the following sample config file:

#===============================================================================
# main device config

Device:
    # Name of the device on the network.
    Name: MeadowF7V2_ConfigSample

#===============================================================================
# Control how the ESP coprocessor will start and operate.

Coprocessor:

    # Should the ESP32 automatically attempt to connect to an access point at startup?
    # If set to true, wifi.yaml credentials must be stored in the device.

    AutomaticallyStartNetwork: true

    # Should the ESP32 automatically reconnect to the configured access point?
    AutomaticallyReconnect: true

    # Maximum number of retry attempts for connections etc. before an error code is returned.
    MaximumRetryCount: 7

# Network configuration.
Network:

    # Automatically attempt to get the time at startup?
    GetNetworkTimeAtStartup: true

    # Time synchronization period in seconds.
    NtpRefreshPeriod: 600

    # Name of the NTP servers.
    NtpServers:
        - 0.pool.ntp.org
        - 1.pool.ntp.org
        - 2.pool.ntp.org
        - 3.pool.ntp.org

    # IP addresses of the DNS servers.
    DnsServers:
        - 1.1.1.1
        - 8.8.8.8

The Device section contains configurable properties for the system in general. The Coprocessor section of the file determines how the coprocessor interacts with the STM32 and the network.

Device Name

This is the name that will show on the network.

Default value: MeadowF7

AutomaticallyStartNetwork

This parameter determines if the system will automatically attempt to connect to an access point as the board starts. This requires a default access point to be configured (see the description of the wifi.yaml file below).

Valid values are:

  • false - Do not connect (default)
  • true - Automatically connect if a default access point has been specified

AutomaticallyReconnect

This parameter determines if the system should automatically attempt to reconnect to an access point if there is a communication issue and the connection is dropped.

Valid values are:

  • false - Do not reconnect (default)
  • true - Automatically try to reconnect

Reconnection attempts are limited by the MaximumRetryCount parameter.

Note that this parameter does not force the system to start the network automatically, see AutomaticallyStartNetwork for this functionality.

MaximumRetryCount

Ths property determines the maximum number of retry attempts for network operations should a failure occur.

Default value: 3

GetNetworkTimeAtStartup

Whether or not the Meadow should attempt to request the latest network time from an Network Time Protocol (NTP) server.

If set to true, NTP servers should be specified.

DnsServers

DNS server(s) to use for DNS queries.

wifi.config.yaml

The wifi.config.yaml file can be used to set the default access point and the password for that access point. The wifi.yaml file should look something like this:

Credentials:
    Ssid: YourSSID
    Password: SSIDPassword

This file will be processed after the meadow.config.yaml file. The Ssid name will be set as the default access point to be used as the system starts. The password will be used when connecting to the access point.

The wifi.config.yaml file will be deleted from flash storage after it has been processed and stored in secure storage on the ESP32 as the information is considered sensitive. This prevents the possibility of the file being read at a later point in time.

The contents of this file along with the AutomaticallyStartNetwork value in meadow.config.yaml can be used to automatically connect to an access point when the board starts.

Sample Apps

For an example of configuration in use, see the Config Files sample App in the Meadow.Core.Samples repo.

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These docs are open source. If you find an issue, please file a bug, or send us a pull request. And if you want to contribute, we'd love that too!