Params ex-client

You can use the higher-level IParamsClientEx, which provides convenient caching, synchronization, and simplified parameter access.

var paramsEx = device.GetMicroservice<IParamsClientEx>() 
    ?? throw new Exception("ParamsClientEx not found");

After that, you can read all parameters and cache them locally:

// Read all parameters from the remote device
await paramsEx.ReadAll(progress: new Progress<double>(p => 
{
    Console.WriteLine($"Progress: {p:P0}");
}));

// Now you can access parameters from the local cache
foreach (var param in paramsEx.Items)
{
    Console.WriteLine($"{param.Key}: {param.Value.Value}");
}

You can read or write individual parameters:

// Read a parameter (updates cache)
var value = await paramsEx.ReadOnce("BARO_PRIMARY");
Console.WriteLine($"Value: {value}");

// Write a parameter (updates cache)
var newValue = await paramsEx.WriteOnce("BARO_PRIMARY", new MavParamValue((byte)1));
Console.WriteLine($"New value: {newValue}");

Subscribe to parameter changes:

// Subscribe to all parameter changes
using var subscription = paramsEx.OnValueChanged.Subscribe(change =>
{
    Console.WriteLine($"Parameter {change.Item1} changed to {change.Item2}");
});

// Or filter for a specific parameter
using var specificParam = paramsEx.Filter("BARO_PRIMARY").Subscribe(value =>
{
    Console.WriteLine($"BARO_PRIMARY changed to {value}");
});

Check synchronization status:

using var syncStatus = paramsEx.IsSynced.Subscribe(isSynced =>
{
    Console.WriteLine($"Parameters synced: {isSynced}");
});

IParamsClientEx (source)

Exposes members to interact with parameters.

Property	Type	Description
`Base`	`IParamsClient`	Base parameter client interface from which this extension interface is derived.
`OnValueChanged`	`Observable<(string, MavParamValue)>`	Observable that emits when any parameter value changes.
`IsSynced`	`ReadOnlyReactiveProperty<bool>`	Indicates if parameters are synchronized with remote device.
`Items`	`IReadOnlyObservableDictionary<string, ParamItem>`	Collection of cached parameters from the remote device.
`RemoteCount`	`ReadOnlyReactiveProperty<int>`	Number of parameters on the remote device.
`LocalCount`	`ReadOnlyReactiveProperty<int>`	Number of parameters in the local cache.

Method	Return Type	Description
`ReadAll(IProgress<double>? progress = null, bool readMissedOneByOne = true, CancellationToken cancel = default)`	`Task`	Reads all parameters from remote device and populates cache.
`ReadOnce(string name, CancellationToken cancel = default)`	`Task<MavParamValue>`	Reads a parameter from remote device and updates local cache.
`WriteOnce(string name, MavParamValue value, CancellationToken cancel = default)`	`Task<MavParamValue>`	Writes a parameter to remote device and updates local cache.
`Filter(string name)`	`Observable<MavParamValue>`	Filters parameter changes for a specific parameter name.
`GetFromCacheOrReadOnce(string name, CancellationToken cancel = default)`	`ValueTask<MavParamValue>`	Gets parameter from cache or reads it from remote device.

`IParamsClientEx.ReadAll`

Parameter	Type	Description
`progress`	`IProgress<double>?`	Optional progress tracker (reports 0.0 to 1.0).
`readMissedOneByOne`	`bool`	If true, reads missed parameters individually after bulk read.
`cancel`	`CancellationToken`	Optional cancellation token.

`IParamsClientEx.ReadOnce`

Parameter	Type	Description
`name`	`string`	Parameter name.
`cancel`	`CancellationToken`	(Optional) The cancellation token.

`IParamsClientEx.WriteOnce`

Parameter	Type	Description
`name`	`string`	Parameter name (max 16 chars).
`value`	`MavParamValue`	Parameter value to write.
`cancel`	`CancellationToken`	(Optional) The cancellation token.

`IParamsClientEx.Filter`

Parameter	Type	Description
`name`	`string`	Parameter name to filter for.

`IParamsClientEx.GetFromCacheOrReadOnce`

Parameter	Type	Description
`name`	`string`	Parameter name.
`cancel`	`CancellationToken`	(Optional) The cancellation token.

Last modified: 31 October 2025