Starting out with BLE - can multiple services be advertised?

[dvh]

Hello everyone!

I'm working on a tiny project where I'd like some connectivity between my phone and a BLE enabled devboard (ESP-WROOM-32). Ideally, it'd be a non-connectable, undirected broadcaster with pieces of sensor data embedded in advertisement packets.

I've been digging through some arduino BLE libraries and found a wrapper aroundmyNewt nimble for Arduino.

Right out of the box, I got into problems with advertising multiple services. Here is my code:

Code: [Select]

#include <NimBLEDevice.h>

// [url]https://www.uuidgenerator.net/[/url]

#define SERVICE_UUID1        "4fafc201-1fb5-459e-8fcc-c5c9c331914b"
#define SERVICE_UUID2        "525bb0f4-7856-47d8-8f92-7f209aa3fb2e"

static NimBLEUUID serviceID1(SERVICE_UUID1);
static NimBLEUUID serviceID2(SERVICE_UUID2);
static NimBLEAdvertising *pAdvert = nullptr;
static uint32_t count = 0;

void setup() {
  Serial.begin(115200);
  Serial.println("Starting BLE work!"); 

  NimBLEDevice::init("SmartPot"); 
  pAdvert = NimBLEDevice::getAdvertising();
}

void loop() {

  pAdvert->stop();
  pAdvert->setAdvertisementType(BLE_GAP_CONN_MODE_NON);
  pAdvert->setServiceData(serviceID1, std::string((char*)&count, sizeof(count))); 
  pAdvert->setServiceData(serviceID2, std::string("bleh"));

  pAdvert->start();   
  Serial.printf("Advertising count = %d\n", count);
  count++;
  delay(5000);
}
Questions:

• Am I correct assuming that it should be possible to advert multiple 128 bit services with data by the spec?
• Could it be that it's the wrapper that does something weird for which reason the code sample doesn't work?
• Do you have experience with that library? Should I keep investing time learning it or should I go straight to ESP-IDF?
• Do you have recommendations for a decent higher level abstraction for working with BLE & Arduino?

Thanks in advance!

[Smokey]

https://docs.silabs.com/bluetooth/2.13/general/adv-and-scanning/bluetooth-adv-data-basics

[dvh]

That didn't help much.

But I managed to piece together from other sources that there is a 31 octet limit on the size of the advert packet. If I want to advertise multiple services, I have to implement scan response too.