I have built the program as described in the YouTube article youtube.com/watch?v=gL7b8E_5aYs. The HC05 connected to the Arduino Uno is paired the Samsung smartphone.
When the slider in the app is moved an error appears "Error 515: Not connected to a Bluetooth device". The first ListPicker1 block calls and connects BluetoothClient1 . Text1 reads "not connected" in red.
I am a Bluetooth newbie. Can you help me???
Thanks in advance.
Please download and post each of those event block(s)/procedures here ...
(sample video)
I'm sorry to say, that as a bluetooth and AppInventor
newbie, I didn't understand the solution you provided.
I changed out the HC05 and left it un-powered while I reloaded the Arduino code but it made no difference.
What solution?
I posted a video to show you how to download your blocks and post them to this board.
The sample blocks I used were from a long time ago, for a different poster, and saved for people who don't know how to download blocks and how to post them to this board.
Those old blocks were not a solution to your specific problem.
Post your code and your blocks.
Thanks, I'll try to download my blocks.
I have three blocks in 3 png files in my Download directory. How do I upload the .png files so they are useful to you?
to remove this post
This means that the problem code is probably in the event that responds to the slider moving.
Could you upload that event block here?
btw your clock example blocks from the screenshot will not help you to find out, if there still is a connection...
as the bluetooth protocol was designed, there is no way to detect, if a connection still is alive, therefore you have to send regularly (i.e. poll) some data to the device. And if you get an error, then you know, that the connection was lost…
also this
set Label1.Text to "Is connected" there
Taifun
Trying to push the limits! Snippets, Tutorials and Extensions from Pura Vida Apps by 
Taifun.
@eugenejasper968 add an if condition like this
if BluetoothClient.IsConnected
then Send1ByteNumber...
Taifun
@Taifun your wrote: 'as the bluetooth protocol was designed, there is no way to detect, if a connection still is alive'. What is then is the purpose of
?
M
From the documentation Connectivity
IsConnected
Returns
frueif a connection to a Bluetooth device has been made.
Taifun
Thank you for your quick response.
To me these two statements contradict each other:
frue if a connection to a Bluetooth device has been made'There must be some sort of semantic difference that I do not understand. As I am struggling with BT connections and designing the logic around them, I would very much appreciate if you could explain why there is no contradiction.
Thank you for your reply and the many previous posts you have made which I find most valuable.
This means, once there is a connection, the property IsConnected stays true even if the connection is lost.
As already said earlier
Taifun
