Hi,
i'm developing an app that uses data from external device, using BluetoothClient.
The external device sends data every 0.2 seconds or so, and I receive it using the Clock.timer event.
For some reason (which I am not really sure about) it makes some weird error- I get two values in one call of "Clock.timer".
I think that the reason to this is that the "Clock.timer" runs every less than 0.2 seconds.
I want to know if there is some event related to data received by bluetooth that can notify me when new data has really recieved. it seems much more right way to get continuous data from bluetooth, than using timer event. If there is not such notifier, I would like to have some advises for getting continuous data from bluetooth.
Thanks in advance.
Please see the Delimiter article in FAQ
Be sure to use println() at the end of each message to send from the sending device, to signal end of message. Do not rely on timing for this, which is unreliable.
In the AI2 Designer, set the Delimiter attribute of the BlueTooth Client component to 10 to recognize the End of Line character.
Also, return data is not immediately available after sending a request,
you have to start a Clock Timer repeating and watch for its arrival in the Clock Timer event. The repeat rate of the Clock Timer should be faster than the transmission rate in the sending device, to not flood the AI2 buffers.
In your Clock Timer, you should check
Is the BlueTooth Client still Connected?
Is Bytes Available > 0?
IF Bytes Available > 0 THEN
set message var to BT.ReceiveText(-1)
This takes advantage of a special case in the ReceiveText block:
ReceiveText(numberOfBytes)
Receive text from the connected Bluetooth device. If numberOfBytes is less than 0, read until a delimiter byte value is received.
If you are sending multiple data values per message separated by | or comma, have your message split into a local or global variable for inspection before trying to select list items from it. Test if (length of list(split list result) >= expected list length) before doing any select list item operations, to avoid taking a long walk on a short pier. This bulletproofing is necessary in case your sending device sneaks in some commentary messages with the data values.