Using BeaconNano library with Nano 33 sense fails at stopping and restarting

[scarbonn]

Hi,

I am new to this forum and to Arduino programming. I am working on a project that detects human presence and sends the result by broadcasting a 1 second burst in iBeacon format. I broadcast two different UUIDs depending on presence status (one for present and one for absent)

First, I need to say I understand this is not a normal way of using an iBeacon, but I have no other choice. The receiver I am communicating with only accepts the iBeacon format.

The problem that I am facing is that I can get the Arduino to broadcast only one time. When I stop the beacon, change the UUID and restart it, the program crashes and I need to double-click the reset button to recover. I tried multiple ways and some allowed me to turn the iBeacon on and off a couple of times (less than 5 times at best). The attached test case allows me to send a 1 second burst on the first attempt and then crashes on the next one. Here is the execution summary:

1. Boot, get the "Enter a Key - 'a' for Absent or 'p' for Present to send presence broadcasting:" prompt on the serial monitor
2. Hit the ‘a’ Key then the system Prints “Absent” on the monitor and then broadcasts for 1 second, using the “absent” UUID
3. hit the ‘p’ key : then the system Prints “Present” on the monitor, but nothing else happens (no broadcast) and the board hangs (disconnects from the serial monitor).

If I comment out the calls to the “changeBeaconUUID” code, of course the program works well forever, printing “Absent” every time I hit ‘a’ and printing “Present” every time I hit ‘p’

Has anyone worked with the beaconNano library and successfully changed the UUID on the fly multiple times? I could not find any documented bug or bug fix about this library. There was another thread similar to mine, but it was closed a while ago:

https://forum.arduino.cc/t/arduino-nano-33-ble-as-ibeacon/623266

Thanks in advance for any help

Here's my test case:

#include <ArduinoBLE.h>
#include <BeaconNano.h>
#define oneSecDelay 1000
#define presentUUID "5e3490c7946841a199dd6897cd538d2a"
#define absentUUID "468a81cc1b944cdeb5dd0e3408ed87b8"

    
 void changeBeaconUUID(char* uuidVal)
  { 
    BeaconNano bn;
    bn.setUuid(uuidVal);
    bn.setMajor(1);
    bn.setMinor(2);
    bn.setTx(197);
    bn.startBeacon();
    delay(oneSecDelay);
    bn.stopBeacon();   
    delay(oneSecDelay);
  }
  
void setup() 
  {
    delay(oneSecDelay);
    Serial.begin(115200);
    delay(oneSecDelay);
    Serial.println("Enter a Key - 'a' for Absent or 'p' for Present to send presence broadcasting:");       
    delay(oneSecDelay);
  }

void loop() 
  {
    int keyRead;
    do
      {
        keyRead = Serial.read();  
      }
    while(keyRead != 'p' && keyRead != 'a');
    if (keyRead == 'p')
      {
        Serial.println("Présent");
        delay(oneSecDelay);       
        changeBeaconUUID(presentUUID); 
      }
    if (keyRead == 'a')
      {
        Serial.println("Absent");
        delay(oneSecDelay);       
        changeBeaconUUID(absentUUID);
      } 
  }

[scarbonn]

Quick update: I also tried a different flavor of this library found somewhere else. Even though both use the same version number, they are not the same and they get called differently. I tried a much simpler test case that simply turns the beacon on and off every 30 seconds. It starts broadcasting and stops working on the first attempt to restart:

#include <ArduinoBLE.h>
#include <BeaconNano.h>
#define dly 30000

void setup()
{  
  Beacon.begin("5e3490c7946841a199dd6897cd538d2a",1,1,197);
  Beacon.startBeacon();
  delay (dly);
}

void loop()
{
  Beacon.stopBeacon();
  delay (dly);
  Beacon.startBeacon();
  delay (dly);
}

[cattledog]

There are two issues reported on GitHub for the ArduinoBLE.h library. You may be running into a library issue.

stopAdvertise/startAdvertise doesn't restart #196

ArduinoBLE crashes when BLE.begin BLE.end is called multiple times (possible solution included)
#192

[scarbonn]

Thanks @cattledog . Being new to this, I was not sure where to look for the problem and kept searching only for known bug in the BeaconNano library. Now, at least, I will be looking in the right direction. Thanks again.

[scarbonn]

@cattledog I tried the solution proposed by @Klaus_K in the issue #192 reported in Github that you mentioned above:

ArduinoBLE crashes when BLE.begin BLE.end is called multiple times (possible solution included)
#192

And although this seems like Klaus is really correcting a real bug, my problem seems to come from somewhere else, since I still have the same problem. It seems like this other issue that you mentioned:

stopAdvertise/startAdvertise doesn't restart #196

Could be my problem. Unfortunately, I searched everywhere and there doesn't seem to be any bug fix available for this yet. I am on a time crunch and don't know where to look for some possible fix. Anyone has any idea when a new library is due to be released and if a bug fix is or will be available for issue #196 above?

Thanks in advance for your help.

[cattledog]

I really don't know what to say, in that you are probably the world expert on using a Nano33 BLE as an ibeacon using the Arduino ide.

Perhaps there is something in the meded layer for the nrf52840, or with proprietary protocols using Nordic tools device, but that's all beyond me.