BLEScanResults getcount() returns zero in 1.0.5-rc4

[Ben79543]

I have tried to run the standard supplied BLE_scan.ino example code - not a single change to it.
It's running fine when I am on 1.0.4 - I get the list of detected devices, and it tells me "found devices: 6" for instance.

When I switch (via board manager) to 1.0.5-rc4:

• I still get all the detected devices so the BLE works fine.
• BUT at the end I get "Devices found: 0" eventhough it found many devices.

Something broken with getCount()?

Hardware:

Board: ESP32 Dev Module
Core Installation version: 1.0.4 and 1.0.5-rc4
IDE name: Arduino IDE 1.8.12
Flash Frequency: 80Mhz
PSRAM enabled: no
Upload Speed: 115200
Computer OS: Windows 10

Logs with 1.0.4 (working): (note I remove the middle lengthy part)

7:14:39.953 -> [D][FreeRTOS.cpp:189] take(): Semaphore taking: name: ScanEnd (0x3ffdd1b0), owner: <N/A> for start
17:14:39.953 -> [D][FreeRTOS.cpp:198] take(): Semaphore taken: name: ScanEnd (0x3ffdd1b0), owner: start
17:14:40.136 -> [D][BLEAdvertisedDevice.cpp:418] setRSSI(): - setRSSI(): rssi: -73
17:14:40.136 -> [D][BLEAdvertisedDevice.cpp:247] parseAdvertisement(): Type: 0x01 (), length: 1, data: 06
17:14:40.136 -> [D][BLEAdvertisedDevice.cpp:247] parseAdvertisement(): Type: 0x03 (), length: 2, data: aafe
17:14:40.136 -> [D][BLEAdvertisedDevice.cpp:447] setServiceUUID(): - addServiceUUID(): serviceUUID: 0000feaa-0000-1000-8000-00805f9b34fb
17:14:40.136 -> [D][BLEAdvertisedDevice.cpp:247] parseAdvertisement(): Type: 0x16 (), length: 16, data: aafe20000bf1120002f0688736cc328e
.....
17:14:41.666 -> [D][BLEScan.cpp:97] handleGAPEvent(): Ignoring ac:23:3f:5b:d7:7e, already seen it.
17:14:41.761 -> [D][BLEScan.cpp:97] handleGAPEvent(): Ignoring 69:2b:92:de:9a:92, already seen it.
17:14:41.761 -> [D][BLEScan.cpp:97] handleGAPEvent(): Ignoring cc:b8:a8:1d:11:c7, already seen it.
17:14:41.761 -> [D][BLEAdvertisedDevice.cpp:418] setRSSI(): - setRSSI(): rssi: -72
17:14:41.761 -> [D][BLEAdvertisedDevice.cpp:247] parseAdvertisement(): Type: 0x01 (), length: 1, data: 06
17:14:41.806 -> [D][BLEAdvertisedDevice.cpp:247] parseAdvertisement(): Type: 0xff (), length: 6, data: ff0317423800
17:14:41.806 -> [D][BLEAdvertisedDevice.cpp:395] setManufacturerData(): - manufacturer data: ff0317423800
17:14:41.806 -> [D][BLEAdvertisedDevice.cpp:247] parseAdvertisement(): Type: 0x07 (), length: 16, data: 110544e4240034004854495720000000
17:14:41.806 -> [D][BLEAdvertisedDevice.cpp:447] setServiceUUID(): - addServiceUUID(): serviceUUID: 00000020-5749-5448-0034-0024e4440511
17:14:41.806 -> [D][BLEAdvertisedDevice.cpp:247] parseAdvertisement(): Type: 0x09 (), length: 11, data: 4163746976697465203131
17:14:41.851 -> [D][BLEAdvertisedDevice.cpp:407] setName(): - setName(): name: Activite 11
17:14:41.851 -> [D][BLEAdvertisedDevice.cpp:247] parseAdvertisement(): Type: 0x0a (), length: 1, data: 00
17:14:41.851 -> [D][BLEAdvertisedDevice.cpp:478] setTXPower(): - txPower: 0
17:14:41.851 -> Advertised Device: Name: Activite 11, Address: 3b:0d:50:d3:8f:53, manufacturer data: ff0317423800, serviceUUID: 00000020-5749-5448-0034-0024e4440511, txPower: 0
17:14:41.898 -> [D][BLEScan.cpp:97] handleGAPEvent(): Ignoring 69:2b:92:de:9a:92, already seen it.
17:14:41.990 -> [D][BLEScan.cpp:97] handleGAPEvent(): Ignoring ac:23:3f:24:0d:6a, already seen it.
17:14:42.083 -> [D][BLEScan.cpp:97] handleGAPEvent(): Ignoring 69:2b:92:de:9a:92, already seen it.
17:14:42.179 -> [D][BLEScan.cpp:97] handleGAPEvent(): Ignoring 69:2b:92:de:9a:92, already seen it.
17:14:42.272 -> [D][BLEScan.cpp:97] handleGAPEvent(): Ignoring 69:2b:92:de:9a:92, already seen it.
17:14:42.319 -> [D][BLEScan.cpp:97] handleGAPEvent(): Ignoring ac:23:3f:24:0d:64, already seen it.
17:14:42.367 -> [D][BLEScan.cpp:97] handleGAPEvent(): Ignoring 69:2b:92:de:9a:92, already seen it.
17:14:42.458 -> [D][BLEScan.cpp:97] handleGAPEvent(): Ignoring 69:2b:92:de:9a:92, already seen it.
17:14:44.598 -> [D][BLEScan.cpp:97] handleGAPEvent(): Ignoring 69:2b:92:de:9a:92, already seen it.
17:14:44.645 -> [D][BLEScan.cpp:97] handleGAPEvent(): Ignoring ac:23:3f:24:0d:6a, already seen it.
17:14:44.692 -> [D][BLEScan.cpp:97] handleGAPEvent(): Ignoring cc:b8:a8:1d:11:c7, already seen it.
17:14:44.785 -> [D][BLEScan.cpp:97] handleGAPEvent(): Ignoring 69:2b:92:de:9a:92, already seen it.
17:14:44.969 -> [W][BLEScan.cpp:69] handleGAPEvent(): ESP_GAP_SEARCH_INQ_CMPL_EVT
17:14:44.969 -> Devices found: 6
17:14:44.969 -> Scan done!

LOGS with 1.0.5-rc4 (note I remove the middle lengthy part)

17:39:48.438 -> [D][BLEAdvertisedDevice.cpp:461] setRSSI(): - setRSSI(): rssi: -67
17:39:48.438 -> [D][BLEAdvertisedDevice.cpp:281] parseAdvertisement(): Type: 0xff (), length: 29, data: 06000109200201338a26d55e1b0eb226f272824fa0a7465cae3f2cd93e
17:39:48.438 -> [D][BLEAdvertisedDevice.cpp:438] setManufacturerData(): - manufacturer data: ...........
17:39:52.098 -> Advertised Device: Name: , Address: ac:23:3f:24:0d:6a, serviceUUID: 0000feaa-0000-1000-8000-00805f9b34fb
17:39:52.146 -> [D][BLEAdvertisedDevice.cpp:461] setRSSI(): - setRSSI(): rssi: -65
17:39:52.146 -> [D][BLEAdvertisedDevice.cpp:281] parseAdvertisement(): Type: 0xff (), length: 29, data: 06000109200201338a26d55e1b0eb226f272824fa0a7465cae3f2cd93e
17:39:52.146 -> [D][BLEAdvertisedDevice.cpp:438] setManufacturerData(): - manufacturer data: 06000109200201338a26d55e1b0eb226f272824fa0a7465cae3f2cd93e
17:39:52.146 -> Advertised Device: Name: , Address: 47:57:f9:f6:1f:80, manufacturer data: 06000109200201338a26d55e1b0eb226f272824fa0a7465cae3f2cd93e
17:39:52.238 -> [D][BLEAdvertisedDevice.cpp:461] setRSSI(): - setRSSI(): rssi: -59
17:39:52.238 -> [D][BLEAdvertisedDevice.cpp:281] parseAdvertisement(): Type: 0xff (), length: 29, data: 06000109200201338a26d55e1b0eb226f272824fa0a7465cae3f2cd93e
17:39:52.238 -> [D][BLEAdvertisedDevice.cpp:438] setManufacturerData(): - manufacturer data: 06000109200201338a26d55e1b0eb226f272824fa0a7465cae3f2cd93e
17:39:52.238 -> Advertised Device: Name: , Address: 47:57:f9:f6:1f:80, manufacturer data: 06000109200201338a26d55e1b0eb226f272824fa0a7465cae3f2cd93e
17:39:52.328 -> [D][BLEAdvertisedDevice.cpp:461] setRSSI(): - setRSSI(): rssi: -80
17:39:52.328 -> [D][BLEAdvertisedDevice.cpp:281] parseAdvertisement(): Type: 0xff (), length: 29, data: 06000109200201338a26d55e1b0eb226f272824fa0a7465cae3f2cd93e
17:39:52.328 -> [D][BLEAdvertisedDevice.cpp:438] setManufacturerData(): - manufacturer data: 06000109200201338a26d55e1b0eb226f272824fa0a7465cae3f2cd93e
17:39:52.375 -> Advertised Device: Name: , Address: 47:57:f9:f6:1f:80, manufacturer data: 06000109200201338a26d55e1b0eb226f272824fa0a7465cae3f2cd93e
17:39:52.421 -> [D][BLEAdvertisedDevice.cpp:461] setRSSI(): - setRSSI(): rssi: -67
17:39:52.421 -> [D][BLEAdvertisedDevice.cpp:281] parseAdvertisement(): Type: 0xff (), length: 29, data: 06000109200201338a26d55e1b0eb226f272824fa0a7465cae3f2cd93e
17:39:52.421 -> [D][BLEAdvertisedDevice.cpp:438] setManufacturerData(): - manufacturer data: 06000109200201338a26d55e1b0eb226f272824fa0a7465cae3f2cd93e
17:39:52.468 -> Advertised Device: Name: , Address: 47:57:f9:f6:1f:80, manufacturer data: 06000109200201338a26d55e1b0eb226f272824fa0a7465cae3f2cd93e
17:39:52.654 -> [D][BLEAdvertisedDevice.cpp:461] setRSSI(): - setRSSI(): rssi: -67
17:39:52.699 -> [D][BLEAdvertisedDevice.cpp:281] parseAdvertisement(): Type: 0xff (), length: 29, data: 06000109200201338a26d55e1b0eb226f272824fa0a7465cae3f2cd93e
17:39:52.699 -> [D][BLEAdvertisedDevice.cpp:438] setManufacturerData(): - manufacturer data: 06000109200201338a26d55e1b0eb226f272824fa0a7465cae3f2cd93e
17:39:52.699 -> Advertised Device: Name: , Address: 47:57:f9:f6:1f:80, manufacturer data: 06000109200201338a26d55e1b0eb226f272824fa0a7465cae3f2cd93e
17:39:52.744 -> [D][BLEAdvertisedDevice.cpp:461] setRSSI(): - setRSSI(): rssi: -67
17:39:52.744 -> [D][BLEAdvertisedDevice.cpp:281] parseAdvertisement(): Type: 0x01 (), length: 1, data: 06
17:39:52.744 -> [D][BLEAdvertisedDevice.cpp:281] parseAdvertisement(): Type: 0x03 (), length: 2, data: aafe
17:39:52.744 -> [D][BLEAdvertisedDevice.cpp:490] setServiceUUID(): - addServiceUUID(): serviceUUID: 0000feaa-0000-1000-8000-00805f9b34fb
17:39:52.744 -> [D][BLEAdvertisedDevice.cpp:281] parseAdvertisement(): Type: 0x16 (), length: 16, data: aafe20000cbd1300008b478804e6e200
17:39:52.744 -> [D][BLEAdvertisedDevice.cpp:511] setServiceDataUUID(): - addServiceDataUUID(): serviceDataUUID: 0000feaa-0000-1000-8000-00805f9b34fb
17:39:52.790 -> Advertised Device: Name: , Address: ac:23:3f:5b:d7:7e, serviceUUID: 0000feaa-0000-1000-8000-00805f9b34fb
17:39:52.835 -> [D][BLEAdvertisedDevice.cpp:461] setRSSI(): - setRSSI(): rssi: -60
17:39:52.835 -> [D][BLEAdvertisedDevice.cpp:281] parseAdvertisement(): Type: 0xff (), length: 29, data: 06000109200201338a26d55e1b0eb226f272824fa0a7465cae3f2cd93e
17:39:52.835 -> [D][BLEAdvertisedDevice.cpp:438] setManufacturerData(): - manufacturer data: 06000109200201338a26d55e1b0eb226f272824fa0a7465cae3f2cd93e
17:39:52.835 -> Advertised Device: Name: , Address: 47:57:f9:f6:1f:80, manufacturer data: 06000109200201338a26d55e1b0eb226f272824fa0a7465cae3f2cd93e
17:39:52.975 -> [D][BLEAdvertisedDevice.cpp:461] setRSSI(): - setRSSI(): rssi: -65
17:39:52.975 -> [D][BLEAdvertisedDevice.cpp:281] parseAdvertisement(): Type: 0x01 (), length: 1, data: 06
17:39:52.975 -> [D][BLEAdvertisedDevice.cpp:281] parseAdvertisement(): Type: 0x03 (), length: 2, data: aafe
17:39:52.975 -> [D][BLEAdvertisedDevice.cpp:490] setServiceUUID(): - addServiceUUID(): serviceUUID: 0000feaa-0000-1000-8000-00805f9b34fb
17:39:52.975 -> [D][BLEAdvertisedDevice.cpp:281] parseAdvertisement(): Type: 0x16 (), length: 16, data: aafe20000bf1120002f06f1636cc6d9e
17:39:53.021 -> [D][BLEAdvertisedDevice.cpp:511] setServiceDataUUID(): - addServiceDataUUID(): serviceDataUUID: 0000feaa-0000-1000-8000-00805f9b34fb
17:39:53.021 -> Advertised Device: Name: , Address: ac:23:3f:24:0d:6a, serviceUUID: 0000feaa-0000-1000-8000-00805f9b34fb
17:39:53.113 -> [D][BLEAdvertisedDevice.cpp:461] setRSSI(): - setRSSI(): rssi: -60
17:39:53.113 -> [D][BLEAdvertisedDevice.cpp:281] parseAdvertisement(): Type: 0xff (), length: 29, data: 06000109200201338a26d55e1b0eb226f272824fa0a7465cae3f2cd93e
17:39:53.161 -> [D][BLEAdvertisedDevice.cpp:438] setManufacturerData(): - manufacturer data: 06000109200201338a26d55e1b0eb226f272824fa0a7465cae3f2cd93e
17:39:53.161 -> Advertised Device: Name: , Address: 47:57:f9:f6:1f:80, manufacturer data: 06000109200201338a26d55e1b0eb226f272824fa0a7465cae3f2cd93e
17:39:53.207 -> [D][BLEAdvertisedDevice.cpp:461] setRSSI(): - setRSSI(): rssi: -84
17:39:53.207 -> [D][BLEAdvertisedDevice.cpp:281] parseAdvertisement(): Type: 0xff (), length: 29, data: 06000109200201338a26d55e1b0eb226f272824fa0a7465cae3f2cd93e
17:39:53.252 -> [D][BLEAdvertisedDevice.cpp:438] setManufacturerData(): - manufacturer data: 06000109200201338a26d55e1b0eb226f272824fa0a7465cae3f2cd93e
17:39:53.252 -> Advertised Device: Name: , Address: 47:57:f9:f6:1f:80, manufacturer data: 06000109200201338a26d55e1b0eb226f272824fa0a7465cae3f2cd93e
17:39:53.345 -> [D][BLEAdvertisedDevice.cpp:461] setRSSI(): - setRSSI(): rssi: -66
17:39:53.345 -> [D][BLEAdvertisedDevice.cpp:281] parseAdvertisement(): Type: 0xff (), length: 29, data: 06000109200201338a26d55e1b0eb226f272824fa0a7465cae3f2cd93e
17:39:53.345 -> [D][BLEAdvertisedDevice.cpp:438] setManufacturerData(): - manufacturer data: 06000109200201338a26d55e1b0eb226f272824fa0a7465cae3f2cd93e
17:39:53.345 -> Advertised Device: Name: , Address: 47:57:f9:f6:1f:80, manufacturer data: 06000109200201338a26d55e1b0eb226f272824fa0a7465cae3f2cd93e
17:39:53.392 -> [W][BLEScan.cpp:72] handleGAPEvent(): ESP_GAP_SEARCH_INQ_CMPL_EVT
17:39:53.392 -> Devices found: 0
17:39:53.392 -> Scan done!

[h2zero]

Hi @Ben79543, looks like this recent commit might have broken your use case.

If you are calling BLEScan::setAdvertisedDeviceCallbacks with wantDuplicates set to true I think that will cause this issue. try setting that to false and test.

[Ben79543]

I have changed
pBLEScan->setAdvertisedDeviceCallbacks(new MyAdvertisedDeviceCallbacks());
with
pBLEScan->setAdvertisedDeviceCallbacks(new MyAdvertisedDeviceCallbacks(), false, true);
Same result:

20:12:45.502 -> Devices found: 0
20:12:45.502 -> Scan done!

[h2zero]

Yes you're correct. It seems the change was such that if you set a callback it would not insert the device into the scan results map. It should work if you don't set a callback and parse the results after.

[Ben79543]

I see. But this is really a problem : I need a callback to be able to count the detected device and stop the scan after a threshold. Otherwise the scan ends up crashing. I refer to this issue: #3559

So without the callback this will not work. Any chance this will be fixed?

[h2zero]

I'm not sure what you're code is doing but to avoid the crash issue that you linked you could call clearResults(); before each scan to avoid the memory use. As far as fixing this it might be something for @chegewara to look at or you could PR a fix.

[Ben79543]

Your are very right: when I remove the "setAdvertisedDeviceCallbacks" getCounts returns a value even in 1.0.5

In my case, I need to limit the nember of detected device in a SINGLE scan. A single scan was enough to make the crash happen so I have no time to call for clearResults. This is what happened to me in an environment with hundreds of ble beacons (the hall of a trade show).

my callback is only a counter that stops scan after a threshold:

class MyAdvertisedDeviceCallbacks: public BLEAdvertisedDeviceCallbacks {
    void onResult(BLEAdvertisedDevice advertisedDevice) {
      nbDetectedDevice++;
      Serial.println(nbDetectedDevice);
      if (nbDetectedDevice >= 50) {
        advertisedDevice.getScan()->stop();
      }
    }
};

Looking at BLESCAN.cpp the issue is right there. in 1.0.5 there is a condition (as you saw it) that says: " if has callback, no need to record to vector". This is what's causing my issue. This was probably inserted for a reason. But how can I achieve my goal without a callback (that is to interupt the scan after a threshold before the scan crashes because there are too many devices)
@chegewara ? Wouldn't it make sense to include a "max_detected_device" parameter when running a scan, that will end the scan if that number is reached?

in 1.0.4:

if (!found) {   // If we have previously seen this device, don't record it again.
	m_scanResults.m_vectorAdvertisedDevices.insert(std::pair<std::string, BLEAdvertisedDevice*>(advertisedAddress.toString(), advertisedDevice));
}

if (m_pAdvertisedDeviceCallbacks) {
	m_pAdvertisedDeviceCallbacks->onResult(*advertisedDevice);
}

if(found)
	delete advertisedDevice;

While in 1.0.5-rc4:

if (m_pAdvertisedDeviceCallbacks) { // if has callback, no need to record to vector
						m_pAdvertisedDeviceCallbacks->onResult(*advertisedDevice);
} else if (!m_wantDuplicates && !found) {   // if no callback and not want duplicate, and not already in vector, record it
	m_scanResults.m_vectorAdvertisedDevices.insert(std::pair<std::string, BLEAdvertisedDevice*>(advertisedAddress.toString(), advertisedDevice));
	shouldDelete = false;
}

if (shouldDelete) {
	delete advertisedDevice;
}

[h2zero]

Looks like a workaround would be just to use the callback but create your own vector of devices and limit it in your application.

The suggestion to add a limiter on the number of devices is also a good idea.

[adam-ah]

The official code example is also broken as a result (Devices found: 0) even though the console is showing devices.
It might be a different issue, but the getName() now is always null as well.

[Ben79543]

So as a summary from 1.0.5, the code was changed so that if there is a callback set, the code supposes that the user will do all the device detection data collection in the call back. Therefore it does not create the array of detected devices.

Before 1.0.5 both were happening: callback+constructing the array.

It was changed in commit #3995 (actually the first commit was ok, but a additionnal change was brought and broke my usecase)

I tested a VERY easy fix: I just removed one "ELSE" in 1.0.5-rc6:

if (m_pAdvertisedDeviceCallbacks) { // if has callback, no need to record to vector
	m_pAdvertisedDeviceCallbacks->onResult(*advertisedDevice);
} // else //REMOVING THIS ELSE IS THE FIX**
if (!m_wantDuplicates && !found) {   // if no callback and not want duplicate, and not already in vector, record it
	m_scanResults.m_vectorAdvertisedDevices.insert(std::pair<std::string, BLEAdvertisedDevice*>(advertisedAddress.toString(), advertisedDevice));
	shouldDelete = false;
}

I tested and it works fine again.

not sure what to do I will start with a comment on the problematic commit...

[h2zero]

Yes that seems to be the purpose of the commit. Good fix IMO.

I have recently implemented the ability to cap the number of scanned devices in the NimBLE library, inspired by your use case. If you don't need classic bluetooth, you might want to try NimBLE, it'll also save a lot of ram and flash.

[Ben79543]

I have recently implemented the ability to cap the number of scanned devices in the NimBLE library, inspired by your use case. If you don't need classic bluetooth, you might want to try NimBLE, it'll also save a lot of ram and flash.

Thanks, I might give it a try indeed