Not able to write to my BLE device

[alj8]

Hello

I am trying to write to my BLE device (an educational robot - BlueBot), and I get as far as connecting, recieving notifications from my first characteristic (properties: Notify, Indicate), but I don't manage to write on the second characteristic (properties: Write, WriteWithoutResponse).

I have found a communication protocol for this device online:
https://www.dropbox.com/s/ifcb542962a81f7/Blue-Bot%20Protocol%20with%20Terms%20of%20Use543156238198.pdf.zip?dl=0&file_subpath=%2FBlue-Bot+Protocol+with+Terms+of+Use543156238198.pdf

I was trying to send the hexadecimal string "AA 03 81 11 04 67" of the first example, transformed to bytes, i. e. "170 3 129 17 4 103", but it does not do anything. I was wondering, if I am doing something wrong when typing in the messages to be send? Is there something special I need to consider?

I am still trying to figure out the robot, and I have very little information about it. Therefore I am not sure, if the problem lies with the robot or with my code, respectively in your case, your code. That's why I was asking to see if I needed to fix anything from the input side such that it should work.

Thank you very much for your help! If you need any more info from my side, I am happy to give it to you.

Regards
alj8