Skip to main content

Android Bluetoothsocket

Bluetoothyhteyden muodostaminen koitui projektin haastavimmaksi osuudeksi. Eri Android-versiot ja puhelimet toimivat eri tavoin kun muodostetaan laiteyhteyttä. Lisäksi käytettävä Bluetoothrauta ja Android eivät tykkää toisistaan (http://stackoverflow.com/questions/9052460/with-just-one-particular-bluetooth-spp-module-createrfcommsockettoservicerecor).

Ratkaisuna ongelmaan ohjelmassa käyttäjä voi valita mitä yhdistystapaa käytetään. Jos laiteyhteyksiä ei saa muodostettua, käyttäjä voi vaihtaa yhdistystapaa. Keräsin kaikki löytämäni bluetoothyhdistystavat, joilla jokaiseen testipuhelimeen löytyi oikeat asetukset.
/**
  * Luo socketin laitteeseen. Huom! yhdistämisessä paljon eroja eri
  * laitteiden välillä. Katso API-levelit ja android versioiden vastaavuudet
  * Androidin nettisivuilta. 

  * 

  * Yhdistystapaa voi muuttaa asetuksista. Oletuksena on neljä erilaista tapaa. Kts. 
  * @param device
  * 
  * @throws IOException
  */

 private BluetoothSocket createBluetoothSocket(BluetoothDevice device)
   throws IOException {
  try {
   final Method m;
   BluetoothDevice hxm;
   Log.i(BT_TAG, "Connection "+ MainActivity.CONNECTION_METHOD);
   switch (MainActivity.CONNECTION_METHOD) {
   case RFCOMMSECURE:
    return device.createRfcommSocketToServiceRecord(REMOTE_UUID);    
   case REFLECTION_RFCOMM:
    m = device.getClass().getMethod(
      "createRfcommSocketToServiceRecord",
      new Class[] { UUID.class });
    Log.i(BT_TAG, "createInsecure");
    return (BluetoothSocket) m.invoke(device, REMOTE_UUID);
   case REFLECTION_NOUUID:
    hxm = BluetoothAdapter.getDefaultAdapter().getRemoteDevice(
      device.getAddress());

    m = hxm.getClass().getMethod("createRfcommSocket",
      new Class[] { int.class });
    return (BluetoothSocket) m.invoke(hxm, Integer.valueOf(1));
   case REFLECTION_INSECURE:
    hxm = BluetoothAdapter.getDefaultAdapter().getRemoteDevice(
      device.getAddress());
    m = hxm.getClass().getMethod("createInsecureRfcommSocket",
      new Class[] { int.class });
    return (BluetoothSocket) m.invoke(hxm, Integer.valueOf(1));
   }
  } catch (Exception e) {
   Log.e(BT_TAG, "Could not create Insecure RFComm Connection", e);
  }
  return device.createRfcommSocketToServiceRecord(REMOTE_UUID);
 }

Comments

Popular posts from this blog

I'm not a passionate developer

A family friend of mine is an airlane pilot. A dream job for most, right? As a child, I certainly thought so. Now that I can have grown-up talks with him, I have discovered a more accurate description of his profession. He says that the truth about the job is that it is boring. To me, that is not that surprising. Airplanes are cool and all, but when you are in the middle of the Atlantic sitting next to the colleague you have been talking to past five years, how stimulating can that be? When he says the job is boring, it is not a bad kind of boring. It is a very specific boring. The "boring" you would want as a passenger. Uneventful.  Yet, he loves his job. According to him, an experienced pilot is most pleased when each and every tiny thing in the flight plan - goes according to plan. Passengers in the cabin of an expert pilot sit in the comfort of not even noticing who is flying. As someone employed in a field where being boring is not exactly in high demand, this sounds pro...

PydanticAI + evals + LiteLLM pipeline

I gave a tech talk at a Python meetup titled "Overengineering an LLM pipeline". It's based on my experiences of building production-grade stuff with LLMs I'm not sure how overengineered it actually turned out. Experimental would be a better term as it is using PydanticAI graphs library, which is in its very early stages as of writing this, although arguably already better than some of the pipeline libraries. Anyway, here is a link to it. It is a CLI poker app where you play one hand against an LLM. The LLM (theoretically) gets better with a self-correcting mechanism based on the evaluation score from another LLM. It uses the annotated past games as an additional context to potentially improve its decision-making. https://github.com/juho-y/archipylago-poker

Careful with externalTrafficPolicy

On a project I am working on is hosted in an EKS cluster with the NGINX ingress controller (the one maintained by Kubernetes). It is deployed using it's official official Helm chart, which I realized, after a lengthy debugging session, was a mistake. The initial setup I aimed to improve had several flaws. Firstly, we were using the AWS Classic Load Balancer in front of the nginx ingress in the cluster, which has been deprecated for some time (years?). Continuing to use it makes little sense to us. The second issue was that we were only running one(!) nginx pod, which is quite sketchy since the exposed web services had essentially no high availability.  I switched to the Network Load Balancer (NLB), which was straightforward - I just needed to change the ingress-nginx service annotation to specify the load balancer type as NLB: service.beta.kubernetes.io/aws-load-balancer-type: nlb However, increasing the replica count turned out to be tricky. When I bumped it up to two, I began to ...