Both the Meadow F7 development board and SMT module have WiFi networking via the ESP32 co-processor. The Meadow F7 embedded SMT module also adds optional ethernet capabilities.
Current Beta Limitations
- All SSL Certificates Accepted - SSL connections are supported, but currently, all certificates over TLS (https) are accepted without any validation.
Sample Apps
For example code, see the following networking sample apps in the Meadow.Core.Samples repo:
- Wifi_Basics - Covers the basics of enumerating and connecting to WiFi networks.
- HttpListener - Shows how to respond to HTTP requests with
HttpListenerContext
,HttpListenerRequest
, andHttpListenerResponse
. - Antenna Switching - Shows how to use the antenna API to switch between the onboard and external antenna connection.
WiFi
Connecting to a WiFi Network
To connect to a WiFi network, call the async function Connect
passing in the SSID (network name), and password. It will return Connection.Status
that we can use to verify if the connection was successful or something went wrong so we can handle any scenario.
var connectionResult = await Device.WiFiAdapter.Connect("[SSID]", "[PASSWORD]");
if (connectionResult.ConnectionStatus != ConnectionStatus.Success)
{
throw new Exception($"Cannot connect to network: {connectionResult.ConnectionStatus}");
}
else
{
Console.WriteLine($"IP Address: {Device.WiFiAdapter.IpAddress}");
Console.WriteLine($"Subnet mask: {Device.WiFiAdapter.SubnetMask}");
Console.WriteLine($"Gateway: {Device.WiFiAdapter.Gateway}");
}
Additionally, you can subscribe to the WiFiConnected
event thats triggered whenever Meadow has joined the network.
Device.WiFiAdapter.WiFiConnected += (s, e) =>
{
Console.WriteLine($"Joined network with IP: {Device.WiFiAdapter.IpAddress}.");
};
Scanning for WiFi Networks
You can also scan for WiFi networks via the Scan()
method on the WiFiAdapter
and then access the network list via the Networks
ObservableCollection
property:
protected void ScanForAccessPoints()
{
Console.WriteLine("Getting list of access points.");
ObservableCollection<WifiNetwork> networks = Device.WiFiAdapter.Scan();
if (networks.Count > 0) {
Console.WriteLine("|-------------------------------------------------------------|---------|");
Console.WriteLine("| Network Name | RSSI | BSSID | Channel |");
Console.WriteLine("|-------------------------------------------------------------|---------|");
foreach (WifiNetwork accessPoint in networks) {
Console.WriteLine($"| {accessPoint.Ssid,-32} | {accessPoint.SignalDbStrength,4} | {accessPoint.Bssid,17} | {accessPoint.ChannelCenterFrequency,3} |");
}
} else {
Console.WriteLine($"No access points detected.");
}
}
Performing Requests
Once the network is connected, you can generally use the built-in .NET network methods as usual, however HttpServer
is not availble in this beta.
HttpClient.Request()
Example
The following code illustrates making a request to a web page via the HttpClient
class:
using (HttpClient client = new HttpClient()) {
HttpResponseMessage response = await client.GetAsync(uri);
response.EnsureSuccessStatusCode();
string responseBody = await response.Content.ReadAsStringAsync();
Console.WriteLine(responseBody);
}
Posting
You can also modify the request to POST
data. For example, the following code posts a temperature reading to Adafruit.IO:
using (HttpClient client = new HttpClient()) {
client.DefaultRequestHeaders.Add("X-AIO-Key", [APIO_KEY]);
client.Timeout = TimeSpan.FromMinutes(10);
string temperature = "23.70";
string data = "{\"value\":\"" + temperature + "\"}";
var content = new StringContent(data, Encoding.UTF8, "application/json");
var result = client.PostAsync(uri, content).Result;
}
Antenna
Both the Meadow development board and production module have an onboard ceramic chip antenna and a U.FL connector for an external antenna for the 2.4GHz WiFi and Bluetooth radio.
For more information on getting the curent antenna information and switching, see the Antenna guide.
Creating RESTful Web APIs with Maple Server
If you need to expose simple RESTful Web APIs, Meadow.Foundation includes a lightweight web server called Maple Server that may be useful. Check out the Maple Server guide for more information.
Sample projects
You can look through these for usa samples in our Meadow Core Samples repo or refer to these practical projects available on Hackster.
![]() |
Weather Station Using Public Web Service Using Meadow
|
![]() |
Build a WIFI Connected Clock Using Meadow
|
![]() |
Make a Meadow indoor/outdoor temperature/weather desk clock
|