error = characteristic:read()
Initiates reading the characteristics value. If a listener callback is provided with setValueUpdateListener for this characteristic (see subsection 20.5.2 ) it will be called once the read operation completes and the result can be retrieved via getValue(). There is no guarantee that for every single call to the read function a dedicated call of the callback will happen. The system may decide to combine multiple completions of read requests into a single call of the callback.
|
Parameter |
Type |
Description |
|---|---|---|
|
error |
out string (optional) |
If successful nil is returned, an error message otherwise |
Introduced in platform.apiLevel = '2.5'