RX of BLE extended advertising (Scan) does not work for longer messages

[Links2004]

Hi,

I am tring to send and receive BLE extended advertising frames with 2x ESP32 C3.
TX is working up to 233 bytes in the ServiceData (verifyed by nRF Connect).

But RX does not work and I get 2 onDiscovered callbacks and getServiceData does not find any data.
I tried dumping the raw data and in there are only parts of the original data.

The docs talk about up to 1650 bytes total for the compleate advertisement.

NimBLE-Arduino/docs/Command_line_config.md

Lines 157 to 161 in e6e8019

	`CONFIG_BT_NIMBLE_MAX_EXT_ADV_DATA_LEN`
	Set the max extended advertising data size,
	- Range: 31 - 1650
	- Default is 255

bellow the code to reproduce the problem with to c3 mini boards.

platformio.ini:

[env:esp32-c3-mini]
platform = espressif32
board = esp32-c3-devkitm-1
framework = arduino
lib_deps =
    h2zero/NimBLE-Arduino@^2.3.5

build_flags =
	-DCONFIG_BT_NIMBLE_EXT_ADV=1
	-DCONFIG_BT_NIMBLE_MAX_EXT_ADV_INSTANCES=2
	-DCONFIG_BT_NIMBLE_MAX_EXT_ADV_DATA_LEN=512
	-DMYNEWT_VAL_BLE_TRANSPORT_ACL_SIZE=512
	-DMYNEWT_VAL_BLE_LL_MAX_PKT_SIZE=512
	-DMYNEWT_VAL_BLE_HCI_EVT_BUF_SIZE=550
	-DMYNEWT_VAL_BLE_ACL_BUF_SIZE=550
	-DCONFIG_BT_NIMBLE_DEBUG
	-DCONFIG_NIMBLE_CPP_LOG_LEVEL=3
	-DCONFIG_NIMBLE_CPP_ENABLE_RETURN_CODE_TEXT

#include <Arduino.h>
#include <NimBLEDevice.h>

#define UUID "11787a26-1b23-4ba5-8556-c3b6dbebf71e"
#define LED_PIN 8

class scanCallbacks : public NimBLEScanCallbacks {
    void onDiscovered(const NimBLEAdvertisedDevice * advertisedDevice) override {
        printf("\n");
        printf("Discovered Device: %s\n", advertisedDevice->toString().c_str());
        printf("AdvLength: %d ManufacturerDataCount: %d\n", advertisedDevice->getAdvLength(), advertisedDevice->getManufacturerDataCount());

        auto payload = advertisedDevice->getPayload();
        printf("RAW: %.*s\n", payload.size(), payload.data());
    }

    void onResult(const NimBLEAdvertisedDevice * advertisedDevice) override {
    }

    void onScanEnd(const NimBLEScanResults & results, int reason) override {
        printf("Scan ended reason = %d; restarting scan\n", reason);
        NimBLEDevice::getScan()->start(0, false, true);
    }
} scanCallbacks;

void runRX() {
    // RX
    NimBLEScan * pBLEScan = NimBLEDevice::getScan();
    pBLEScan->setScanCallbacks(&scanCallbacks, true);
    pBLEScan->setActiveScan(false);
    pBLEScan->setMaxResults(0);
    pBLEScan->start(0, false, true);
    printf("Scanning...\n");
}

void runTX() {
    NimBLEExtAdvertising * pAdvertising = NimBLEDevice::getAdvertising();

    NimBLEExtAdvertisement leAdvertising(BLE_HCI_LE_PHY_CODED, BLE_HCI_LE_PHY_2M);

    std::string raw("A fork of the NimBLE library structured for compilation with Arduino, for use with ESP32, nRF5x. A fork of the NimBLE library structured for compilation with Arduino, for use with ESP32, nRF5x. 123456789ABCDEF-123456789ABCDEF-1234567");

    // len max seams to be 233,
    // increasing CONFIG_BT_NIMBLE_MAX_EXT_ADV_DATA_LEN does not work
    // why no 0xFF / 255 ?
    if(!leAdvertising.setServiceData(NimBLEUUID(UUID), raw)) {
        printf("failed to setServiceData\n");
    } else {
        printf("ok to setServiceData len: %d\n", raw.size());
    }

    leAdvertising.setAnonymous(true);
    leAdvertising.setConnectable(false);
    leAdvertising.setScannable(false);
    leAdvertising.setMinInterval(100);
    leAdvertising.setMaxInterval(200);

    printf("BLE leAdvertising len: %d\n", leAdvertising.getDataSize());

    if(!pAdvertising->setInstanceData(0, leAdvertising)) {
        printf("BLE failed to set leAdvertising\n");
    } else if(!pAdvertising->start(0, 0, 0)) {
        printf("BLE failed to start leAdvertising\n");
    } else {
        printf("BLE started leAdvertising\n");
    }
}

void setup() {
    pinMode(LED_PIN, OUTPUT);
    digitalWrite(LED_PIN, false);
    printf("Wait...\n");
    delay(1000);
    printf("Wait...\n");
    delay(1000);
    printf("Wait...\n");
    delay(1000);

    printf("Staring...\n");
    NimBLEDevice::setScanFilterMode(CONFIG_BTDM_SCAN_DUPL_TYPE_DATA_DEVICE);
    NimBLEDevice::init("");

    // runTX();
}

void loop() {
    runRX();

    static bool led = false;

    led = !led;
    digitalWrite(LED_PIN, led);
    delay(200);
}

RX log:

Scanning...
I NimBLEScan: New advertiser: 00:00:00:00:00:00

Discovered Device: Name: , Address: 00:00:00:00:00:00
AdvLength: 229 ManufacturerDataCount: 0
RAW: �!��۶�V��K#zxA fork of the NimBLE library structured for compilation with Arduino, for use with ESP32, nRF5x. A fork of the NimBLE library structured for compilation with Arduino, for 1
I NimBLEScan: New advertiser: 00:00:00:00:00:00

Discovered Device: Name: , Address: 00:00:00:00:00:00
AdvLength: 22 ManufacturerDataCount: 0
RAW: 23456789ABCDEF-1234567

TX log 233 bytes:

Staring...
I NimBLEDevice: BLE Host Task Started
I NimBLEDevice: NimBle host synced.
ok to setServiceData len: 233
BLE leAdvertising len: 251
BLE started leAdvertising

TX log 234 bytes:

Staring...
I NimBLEDevice: BLE Host Task Started
I NimBLEDevice: NimBle host synced.
ok to setServiceData len: 234
BLE leAdvertising len: 252
E NimBLEExtAdvertising: Invalid advertisement data: rc = 530 
BLE failed to set leAdvertising

[h2zero]

The limit is 253 bytes for regular advertising, 1651 only applies when using chaining, which is not supported yet.
https://novelbits.io/maximum-data-bluetooth-advertising-packet-ble/

[Links2004]

thanks, that explains the TX problem, any Idea why RX is not working?

[h2zero]

The RX looks like the controller has reported a legacy advertisement containing the last bytes of your advertisement, which is strange. Try changing to using only the onResult callback and see what you get.

[Links2004]

did move the printing to onResult, but the same result.
intresting it that isLegacyAdvertisement does not report it as Legacy which is correct.

void onResult(const NimBLEAdvertisedDevice * advertisedDevice) override {
        printf("\nonResult\n");
        int rssi = advertisedDevice->getRSSI();
        bool isLegacy = advertisedDevice->isLegacyAdvertisement();
        printf("Discovered Device: %s\n", advertisedDevice->toString().c_str());
        printf("RSSI: %d isLegacy: %d AdvLength: %d ManufacturerDataCount: %d\n", rssi, isLegacy, advertisedDevice->getAdvLength(), advertisedDevice->getManufacturerDataCount());

        auto payload = advertisedDevice->getPayload();
        printf("RAW: %.*s\n", payload.size(), payload.data());
    }

I NimBLEScan: New advertiser: 00:00:00:00:00:00

onResult
Discovered Device: Name: , Address: 00:00:00:00:00:00
RSSI: -79 isLegacy: 0 AdvLength: 229 ManufacturerDataCount: 0
RAW: �!␞��۶�V��K#␛&zx␑A fork of the NimBLE library structured for compilation with Arduino, for use with ESP32, nRF5x. A fork of the NimBLE library structured for compilation with Arduino, for use with ESP32, nRF5x. 123456789ABCDEF-1
I NimBLEScan: New advertiser: 00:00:00:00:00:00

onResult
Discovered Device: Name: , Address: 00:00:00:00:00:00
RSSI: -79 isLegacy: 0 AdvLength: 22 ManufacturerDataCount: 0
RAW: 23456789ABCDEF-1234567

[h2zero]

Thanks! I found an issue and it should be resolved in #1027

[Links2004]

switched to

lib_deps =
    https://github.com/h2zero/NimBLE-Arduino.git#bugfix/extadv-data

and it works, way better.
the only thing I noticed is that the getAdvLength reports the wrong length,
but the size inside of the vector of getPayload is correct.

onResult
Discovered Device: Name: , Address: 00:00:00:00:00:00
Service Data:
UUID: 11787a26-1b23-4ba5-8556-c3b6dbebf71e, Data: A fork of the NimBLE library structured for compilation with Arduino, for use with ESP32, nRF5x. A fork of the NimBLE library structured for compilation with Arduino, for use with ESP32, nRF5x. 123456789ABCDEF-123456789ABCDEF-1234567
RSSI: -67 isLegacy: 0 AdvLength: 229 ManufacturerDataCount: 0
RAW: �!␞��۶�V��K#␛&zx␑A fork of the NimBLE library structured for compilation with Arduino, for use with ESP32, nRF5x. A fork of the NimBLE library structured for compilation with Arduino, for use with ESP32, nRF5x. 123456789ABCDEF-123456789ABCDEF-1234567

[h2zero]

Thanks, I have corrected the data length and fixed update status as well.

[h2zero]

Just pushed another commit to the same branch, advertisements up to 1650 bytes now supported, you can only have up to 251 bytes in a field though.