Android Question BLE2 Library Sending Data

This is where I started: https://www.b4x.com/android/forum/threads/ble-2-bluetooth-low-energy.59937/

I've also attached a development app I created while learning to communicate with an RN4020 BLE device. I'm using it's MLDP mode (a so called SPP equivalent) so it's a little different from communicating with standard BLE devices, but it should give you some ideas to start with. Also, BLE has a 20 byte max limit on write transfers. In my app I use the write complete event to send data in chunks of 20 bytes if necessary, so I can send more or less continuous streams if I need to. If you look at "Manager_Disconnected" you'll see I do retries. I was getting disconnect events without a connect. Doing a connect retry solved the problem. I don't know if it's something odd with BLE itself, or the RN4020 module. You may not have this issue.

Good luck!

Thanks so much for your reply sir. I will read your code later. I'am using bluno bettle as my BLE module.

I tried using their sample from here. Also i got getting disconnected without doing anything. For the data length i just need to pass 1 or 0 to trigger job of bluno bettle. Again sir thanks.
https://www.dfrobot.com/blog-283.html

Sir where did you get this items:

Originally I got those from another example that I started with I found here on this forum. Scroll down a bit to find a zip file from member ac9ts. https://www.b4x.com/android/forum/threads/ble-communication-problem.62461/#post-394784
https://www.b4x.com/android/forum/threads/ble-communication-problem.62461/#post-394784
In the case of the RN4020 MLDP mode they are available from Microchip as well. I also used another app: BLE Scanner that can read the public and private UUIDs of a device. I've attached a screen cap of the RN4020 characteristics from that app.