can you send integer data using BLE ?

[adithrmwn24]

Hello,

I'm using ESP-Vroom-32 for my project. In this board, I connect soil moisture sensor V1.2 and Temperature Sensor DHT-11 Module. I cannot send integer value, but must be converted into a string first and then can be sent.

Is it possible to send integer data using BLE in ESP32 ?

[chegewara]

Yes, you can send integer. https://github.com/nkolban/esp32-snippets/blob/master/cpp_utils/BLERemoteCharacteristic.h#L49 https://github.com/nkolban/esp32-snippets/blob/master/cpp_utils/BLERemoteCharacteristic.h#L51

[prakash-subash]

Dear chegewara,

I need some more explanation about your comments. I am also looking for sending integer data from server to client.

Thank you

[chegewara]

Here is not too much to explain: https://github.com/nkolban/esp32-snippets/blob/master/cpp_utils/BLERemoteCharacteristic.h#L51 sending integer value in range 0-255.

In other hand this can be used to send integer or float values of any kind: https://github.com/nkolban/esp32-snippets/blob/master/cpp_utils/BLERemoteCharacteristic.h#L49

uint8_t is 1 byte long, for example int type is 4 bytes long. uint8_t is pointer to first byte of any value, to make it more elegant it probably should be void. Now if you have int val = 0 then (uint8_t*) &val will point to first byte of val in memory, passing sizeof(int) as length will send all bytes of that integer.

[prakash-subash]

Dear chegewara,

Thanks for you suggestion.

server: syntax for sending integer pCharacteristic->setValue((uint8_t*)&line_current, 4);

client: syntax for receiving integer uint16_t value = pRemoteCharacteristic->readUInt16();

I have got exact data at client end what I expected from server.

Thanks Prakash S

[chegewara]

uint16_t value = pRemoteCharacteristic->readUInt16();

This is sizeof 2 bytes, but you are sending 4 bytes. You have to keep consistent types when you are sending and reading data.