Rongzhong Li, I did note that the name was cached until I actually connected and got into the control and calibration portions of the app. The next time I went to connect to the device after that first connection, it had the correct name in the list of possible connections. I don’t know if that information will help you find where the BLE device name is being cached or not.

Issue resolved. The Testflight version of the Petoi iOS software solved the issue and worked correctly with the M5Stack ported code (based on ESP32 based BiBoard) without modification to the released BiBoard BLE portion of the code. Thanks to Rongzhong Li for the quick response and access to the TestFliight version of the Petoi App!

Another Update. The bluetooth interrogation program I was using would only tell you there was a notification available, but would not allow you to subscribe to it. I found another BLE App (BlueSee) that allows you to subscribe to BLE notification channels. By adding in the commented code that loops the initial notify and changing it to 3 attempts and 1000ms between attempts, I was able to physically see the "Petoi Bittle" notification come in on the notify channel (I did this since the tool I used required me to manually subscribe to the notify each time I connected). See code snippet below: for (byte i = 0; i < CONNECTION_ATTEMPT; i++) {// send the keywords a few times on connection so that the app knows it's a Petoi device pTxCharacteristic->setValue("Petoi Bittle"); //pTxCharacteristic->setValue("Bittle"); pTxCharacteristic->notify(); delay(1000); } I also noted that the commands sent to the RX Characteristic are indeed echoed on the TX Characteristic notify channel once you have subscribed to it. So, I am guessing that the updated IOS TestFlight APP will resolve the issues I am seeing with the older APP. I will let you know how it goes once I receive the APP. I hope this information is useful! Thanks so much!

Thank you for your quick response. I will send you a message so that I can get the TestFlight version. I also have done some more digging using a bluetooth inspector that might be useful to you. I have determined that the Bittle device is in fact able to receive data over bluetooth (via the inspector app on my iMac). Screen shot below: So, the RX Characteristic is working properly. I am guessing with an IOS app update that part will work once it is able to be connected. Below is a snapshot of the Arduino interface with a serial console, and you can see that it is receiving the manually sent command via the Bluetooth interrogation software above the last one being a "d". However, the TX Characteristic does not seem to be working correctly, so the IOS App will not be able to receive anything from the Bittle device. See below screen capture from the Bluetooth Interrogation App. I have spent a bit of time on determining why the TX Characteristic is not able to be accessed using the interrogation tool, but this is a new tool to me and so I may just not be understanding its capabilities. I did try a few modifications to the code to see if I could get the TX Characteristic to allow reads, but I have not been successful yet. I will update this post if I am able to find anything new.

Update, I just used my daughter's iPhone to attempt to connect to the device and it correctly showed the new advertised name of "Bittle6E_SSP". However, it still does not connect and reports the same error code: The device doesn't seem to be a Petoi robot. Upon connection the current ESP code send "Bittle" to the IOS app per the code below. if (deviceConnected && !oldDeviceConnected) { // do stuff here on connecting Serial.println("Bluetooth connected!"); oldDeviceConnected = deviceConnected; delay(HOLD_TIME); // for (byte i = 0; i < CONNECTION_ATTEMPT; i++) {// send the keywords a few times on connection so that the app knows it's a Petoi device //pTxCharacteristic->setValue("Petoi Bittle"); pTxCharacteristic->setValue("Bittle"); pTxCharacteristic->notify(); // delay(100); //} Is this correctly in sync with what the IOS app is expecting to be sent after connection? Thanks!