carlos asked 6 months ago
Hi, I think I have purchased every book you published by RNTL. I have found these books to be great guides to learn more about the ESP32. I have been trying to create a simple bluetooth application that will take the temperature from the DS18B20 one wire temp sensor and send the info to an iPhone. Actually I already used your project from Unit#5 Bluetooth classic and have that running and it works great, unfortunately it will not work with an iPhone. So I have taken the part of the code you have just to gather the sensor temperature and incorporate the ESP32 BLE Server routines but I have come up with a major problem that I can’t seem to solve. The temperature string you get from the sensor is my real problem. The problem I have is that I want to send a long string using the only way I know to send data on BLE:
customCharacteristic.setValue(&Data,n); // This is a value of n bytes to send out
customCharacteristic.notify(); // Notify the client of a change
So I have no idea as to how I could adapt your simple classical bluetooth temperature to a ESP32 BLE type any help or guidance on this would be greatly appreciated.
Thank you for your help
Sara Santos Staff answered 6 months ago
Hi Carlos.
I’m sorry, but I’m not really sure that I understood your question.
You’ve followed this project and it worked: https://rntlab.com/module-11/esp32-ble-android-application-control-outputs-and-display-sensor-readings/ , right?
You want to do the same project using an iPhone? Building compatible apps for iPhone is not an easy task and I don’t know how to do that.
I didn’t understand your problem with the string. What exactly happens? In the project I’ve mentioned the temperature is send to an android app using that method.
Regards,
Sara
carlos answered 6 months ago
Thank you so much Sara for getting back to me so quickly. My question basically was related to the use of the following statement: “pCharacteristic->setValue(txString);” in order to send the temperature string via BLE. But you have answered all my questions by pointing me to the example (module 11) you sent me, I have tried the above and it appear to work with a bluetooth terminal on my iPhone. BTW, I have purchased the “Learn ESP32” 2nd edition book from you but apparently module 11 is not included in this book, is there a newer book or a 3rd edition of this book?
Sara Santos Staff answered 6 months ago
Hi Carlos.
On the 2nd edition of the eBook, the project starts at page 569.
Do you find it?
Regards,
Sara