i want to use this RxAndroidBle library without location permission as my bluetooth device is not a beacon device. so can i scan devices without location permission?
No — you cannot perform a BLE scan on Android 6.0+ devices without Location Permissions as the beacons will get scanned even if your device is not a beacon.
Since Android 6.0 the OS requires Location Permissions to be granted to use the BLE scans. Even more some devices require Location Services to be on to return scan results — if Location Services are off the scan starts normally but does not callback with any scanned devices.
There is one workaround. One may use classic Bluetooth discovery and filter for BLE devices. The downside is that in this way BLE Advertisement Data is not accessible.
Related
Is it possible to setup multiple BLE profiles using Bluez, for use in a single connection?
For example to allow a device to support a GATT profile and also use a PAN network access profile simultaneously.
Thanks
Update:
Thanks for the comment.
What I'm trying to achieve is an embedded device which connects to a phone app over BLE.
This connection will support a GATT protocol for accessing attributes on the device, but also BLE tethering so that the device has a direct internet connection through the phone. And both will work simultaneously.
Its possible. PAN profile and GATT are not depend on each other.
I bought one of these:
https://www.aliexpress.com/item/Smart-finder-Key-finder-Wireless-Bluetooth-Tracker-Anti-lost-alarm-Smart-Tag-Child-Bag-Pet-GPS/32806261079.html
As far as I can tell it is a BLE (Bluetooth Low Energy) location tag.
I downloaded the app for it onto my iphone, and the app instantly recognised it and connected to it. The iPhone app seems to know how far away the tag is - it has a little map of the local area and says how many feet away. I was able to set the device name via the app, but I'm not sure if that set it locally or on the tag itself. The iPhone app also has a "find" button - when you press it, the tag beeps.
So I want to know how I can program this thing myself. I want to be able to identify it when it is nearby, connect to it and make it beep. I've searched for quite a while but not come up with much.
I'm assuming (wrongly/rightly?) that there is some general standard or approach for talking to these BLE location devices and carrying out the basic functions with them - but what is that standard - where is the documentation?
Does anyone have any idea how to program these BLE location tag devices?
BLE devices typically communicate using GATT, either using standard GATT services, or custom ones. The command to make it beep is probably implemented using a custom GATT service.
For finding out the distance to the beacon, typically the RSSI is used. This is a measure of the received power. It needs to be compared to the output power at the emitter. Usually beacons will put their output power in advertisement data, so it can be used without connecting to them. Here since the app is also able to send commands to the beacon, chances are it keeps a connection to it and has a custom GATT protocol to retrieve the output power.
Here is what I would suggest:
Read up on BLE, especially advertising and GATT. For instance read this for advertising and this for GATT. The full BLE spec is available here but should be used for reference and not introduction
Sniff the communication between your device and your phone. You can see this other answer of mine to get started
Replicate the communication protocol in you own app. For that you'll need to use your target platform's BLE libraries. For instance for iOS it is CoreBluetooth
I'm using Android Things 1.0.4 in a prototype where it acts as BLE peripheral device: advertising services and running a GATT server.
I encounter an issue in the BLE pairing process when trying to bond the Android Things board (Raspberry Pi 3) and a smartphone.
Since the device has no display, I set using BluetoothConfigManager:
IoCapability = BluetoothConfigManager.IO_CAPABILITY_NONE
which results in the error AUTH_FAILED every time.
Instead,
IoCapability = BluetoothConfigManager.IO_CAPABILITY_OUT
logs the pairing key and prompts the smartphone to enter it during pairing, but it results in the REMOVED error.
Questions:
Is Android Things in peripheral role capable of handling BLE pairing or not yet?
Are there more things that need to be implemented in the app's code to replicate the full-fledged Android logic?
Here's the source code of the Android Things app to test BLE pairing and bonding
The same code stripped from Android Things specific elements completes BLE pairing and bonding successfully when running on an Android phone as Peripheral (server), and an Android device or iPhone as Central (client).
Generally speaking, if you attempt to read an encrypted GATT characteristic before pairing (which triggers the pairing logic automatically), this results in GATT error 137 returned from the read request (AUTH_FAIL). This is because the device doesn't have enough time to finish setting up the bond before a response is sent by the Bluetooth stack. Retying the read request again generally succeeds.
I have not tested this with an iOS client device, but it certainly holds true with an Android client connecting to an Android (Things) peripheral. As such, I would recommend a few things:
Have the client (mobile) device explicitly initiate pairing, and Android Things should simply react to these incoming requests in the BluetoothPairingCallback. This lets the mobile device decide the pairing type based on the reported capabilities of the IoT device.
Separate the pairing flow from the GATT flow. Pair to the discovered device separately from making any attempts to read the characteristics. This tends to be the best way to avoid timing problems.
Regarding capability choices, this depends on your device. In my experience, if you choose IO_CAPABILITY_NONE this results in PAIRING_VARIANT_CONSENT inside of onPairingInitiated() and the pairing operation succeeds once finishPairing() is called. If you adjust your capabilities, you should be prepared for any number of the variants requiring you to display a PIN for the mobile device to enter. I have not not personally tested these paths.
I am trying to connect to Firebase from an ESP8266 microcontroller. This device has limited RAM and can't handle large TLS fragments. The developer who supports TLS for ESP8266 implemented Maximum Fragment Length Negotiation only to find that Firebase servers ignore it. Is somebody at Firebase listening? Can anything be done to turn on this option on your servers?
You can see the discussion here, towards the bottom.
I use some Esp8266's with Firestore to monitor my foil tunnel for tomatoes and it works good.
I use the Firebase-ESP-Client from mobizt.
https://github.com/mobizt/Firebase-ESP-Client
There is a GPS device which can send data to IP:Port. I have a website hosted on IP 1.2.3.4
Can I send GPS data from the device to that website? 1.2.3.4:8080? How I will retrieve the data?
This is the device
http://cgi.ebay.com/GSM-GPRS-GPS-Vehicle-Car-Tracking-System-Tracker-Device-/270683202099?pt=AU_Car_Parts_Accessories&hash=item3f05f9e233
Maybe this should be a comment...
To be honest we can't answer that question the device will most likely use its own data format(s) so the service that receives from it will have to implement those. Additionally the device might not support web protocols, it could use raw TCP sockets for example, so you may have to implement a listener service that adheres to those protocols. In fact it looks like the device uses GSM (a mobile telephony standard), so using a web site to receive the data is definately off the cards unless you have a GSM proxy service sitting between the device and the web server.
Assuming that you are allowed to implement your own service it follows that the documentation will include the necessary details and if you are lucky a full SDK that you can use.