ESP32 Determine when indication was received

offoffoff · July 21, 2021, 4:01pm

Hi,
I'm working with an ESP32 dev kit trying to get familiar with BLE, but have hit a wall and am not sure what you're supposed to do in this scenario.
What I'd like to do is setup the ESP32 as the peripheral device, then have it send indications (not notifications) to connected client central devices. I have looked through the BLE code and was able to find out how to use indications instead of notifications, but I don't understand how the main app I write would be able to determine when an indication has succeeded vs failed.

Here is the relevant section of the BLE library (Line 475 - 558)

github.com

espressif/arduino-esp32/blob/master/libraries/BLE/src/BLECharacteristic.cpp#L475-L558


      
          void BLECharacteristic::indicate() {
          
          
	log_v(">> indicate: length: %d", m_value.getValue().length());
          	notify(false);
          	log_v("<< indicate");
          } // indicate
          
          

          
/**
           * @brief Send a notify.
           * A notification is a transmission of up to the first 20 bytes of the characteristic value.  An notification
           * will not block; it is a fire and forget.
           * @return N/A.
           */
          void BLECharacteristic::notify(bool is_notification) {
          	log_v(">> notify: length: %d", m_value.getValue().length());
          
          
	assert(getService() != nullptr);
          	assert(getService()->getServer() != nullptr);

This file has been truncated. show original

Both the notify/indicate methods return void. I don't see anything which would suggest that the ESP32 would handle retransmission attempts, so how would I be able to know when to try sending it again?

offoffoff · July 22, 2021, 3:56pm

Edit: I'm blind soemhow missed that there were callbacks available

system · November 19, 2021, 3:57pm

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ESP32 Determine when indication was received

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