Error 507 when connecting Bluetooth between MIT app and Raspberry Pi

Hi everybody, I am very new and learning to program an application . My project is about triggering the application of caregivers when the diapers of bedridden elderly are full and requires change.
I am using a moisture sensor connected to Grovehat on Raspberry Pi Zero WH. The Raspberry Pi Zero WH has Bluetooth 4.1 and BLE bluetooth.

So my current problem is that the after picking the raspberry pi bluetooth on the application, an error code is shown "Error 507, Unable to Connect. Is the device turned on?"

I have already tried to troubleshoot it with some of the suggestions in the posts about the error (except the use of python - because I am really new to coding and have no idea). So, things are still not working even with the troubleshooting :confused:

Will anyone in the community help please? I know the topic has been covered quite a lot, but it seems the solutions are more for arduino.


Thank you very much!

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:

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.

Some people send temperature and humidity in separate messages with distinctive prefixes like "t:" (for temperature) and "h:" (for humidity).
(That's YAML format.)

The AI2 Charts component can recognize these and graph them. See Bluetooth Client Polling Rate - #12 by ABG

To receive YAML format messages, test if the incoming message contains ':' . If true, split it at ':' into a list variable, and find the prefix in item 1 and the value in item 2.

I was able to make the connection but with RPi 3 and Raspbian Buster.

For 507 errors do not enable the clock until after successful connect

Thank you, I also saw this post.
Do you happen to have the blocks in English? :blush:

I am using Redmi note 12 with Android 13.

Thank you I will try this.