Is it doable to define multiple BLE service for Arduino with CurieBLE? Seems all relevant examples are using one service with multiple characteristics.
blePeripheral.addAttribute(xService);
blePeripheral.addAttribute(xCharacteristic);
I know there are blePeripheral.addAttribute, but is it valid and workable to call them and add multiple services?
I have done it both ways. When I add characteristics without the service, GATT still keeps them. Download an analyzer for free and you'll see the service for the characteristic.
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I have been trying to establish a network of ESP8266 (Specifically ESP-01). However, I am not able to find any documentation or anything related on how to actually communicate using HTTP GET and POST methods since I only need a temporary short time communication between multiple sending Nodes to one main Aggregator node.
I don't want to use any Arduino-related libraries as I'm working with STM32. However, I have seen some Arduino-based libraries related to this like ESPAsyncWebServer. But I am not able to find any AT-commands inside it and it's too complicated and intricate for me to understand.
I am basically making a custom library in short so how is communication using HTTP is done between 2 ESPs either using AT commands or any other way (I am going to be communicating to the ESP modules using a dedicated microcontroller through UART) or better if there's any other better way for implementing multiple to 1 connection on ESP. How can I establish this communication to basically send and receive numbers and characters.
I know how to build server api with java. Is it possible to send real time data from the arduino to my server api to save real time data.
Yes it's certainly possible however your server API must also be taken into consideration for best practices.
Typically you would use a protocol called MQTT to achieve this. It enables you to transmit data from resource constrained devices to a server, however HTTP has also been used. It really depends on the kinds of performance & reliability needs of your system.
If you're using a popular cloud platform they offer managed IOT services that provide well defined API's to do this.
I will be asking a very subjective question, but it is important as I am looking to recover from failure to effectively use BlueZ programatically.
Basically I envision an IoT edge device that runs on a miniature computer (Ex: Raspberry pi or Intel Compute Stick). The device would then run AlpineLinux OS and interact with Cloud.
Since it is IoT environment, it is needless to mention the importance of Bluetooth BLE over ISM band. Hence the central importance of being able to customize and work with BlueZ.
I am looking to do several things with BlueZ BLE including but not limited to
Advertising
Pairing
Characteristic
Broadcast
Secure transport of data etc...
Since I will be needing full control over data, for data-processing and interacting with cloud (Edge AI or Data-science on Cloud) I am looking at three ways of using BlueZ:
Make DBus API calls to BlueZ Methods.
Modify BlueZ codebase and make install a custom bin.
(So that callback handlers can be registered and wealth of other bluez
methods can be invoked)
Invoke BlueZ using command line utils like hcitool/bluetoothctl inside a program using system() calls.
No 1 is where I have failed. It is exorbitant amount of effort to construct and export DBus objects and then to invoke BlueZ methods. Plus there is no guarantee that you will be able to take care of all BLE issues.
No 2 looks very promising and I want to fully explore how feasible it is to modify the BlueZ code to my needs.
No 3 is the least desirable option, but I want to have it as a fallback option nevertheless.
Given my problem statement, what is the most viable strategy forward? I am asking this aloud so that I do not make more missteps and cost myself time and efforts.
Your best strategy is to start with the second way (which you already found promising) as this is a viable solution and many developers go about this method in order to create their BlueZ programs. Here is what I would do:-
Write all the functionality of the system in some sort of flowchart or state machine. This helps you visualise your whole system and what needs to be done to reach your end goal.
Try to perform all the above functionality manually using bluetoothctl and btmgmt. This includes advertising, pairing, etc. I recommend steering away from legacy commands such as hcitool and hciconfig as these have been deprecated and have a very different code structure.
When stumbling upon something that is not the default in bluetoothctl/btmgmt or you want to tweak the functionality, update the source to do so.
Finally, once you manually get the system to perform the functionality that you need (it doesn't have to be all, it can just be a subset of the functions), you can move to automating the whole process. This involves modifying the source for bluetoothctl/btmgmt commands so that instead of manual intervention, everything would be event-driven.
This is a bonus, but if you can create automated tests using python or some other scripting language, then this would ensure that your system is robust and that previous functionality doesn't break when adding new ones.
By the end of this process, you'll have a much better understanding of the internals of bluetoothctl/btmgmt and D-BUS APIs that you might be able to completely detach your code from the original bluetoothctl/btmgmt or create the program from scratch.
You probably already know this, but when modifying the tools, this is the starting point for the source code:-
bluetoothctl - client/main.c
btmgmt - tools/btmgmt.c
For more references on using bluetoothctl commands and btmgmt, please see the links below:-
BlueZ D-Bus C or C++ Sample
Bluetoothctl set passkey
https://stackoverflow.com/a/51876272/2215147
Bluez Programming
Linux command line howto accept pairing for bluetooth device without pin
https://stackoverflow.com/a/52982329/2215147
Bluetooth Low Energy in C - using Bluez to create a GATT server
I hope this helps.
Has anyone worked with BLE applications where there is no smartphone (or app) involved with very little ability for computing power? I am formulating something around asset tracking where the use of a smartphone would not be possible and minimal computing power would exist. Is it possible?
Interesting concept. But could you be more descriptive on what exactly are you trying to implement in terms of computing power?
I suppose you could try my opinions below, (Apologies for anyone who disagrees, feel free to add things here)
--> Without a smart phone can be done, if the BLE module can write some serial data to a wifi module on the same board. So you will simply program the wifi module with your wifi name and password so it can transmit logs from ble to the web and with that you could use https://thingspeak.com/ or similar IoT cloud based services to analyze your raw data to a meaningful graphical version.
--> Little ability for computing power?, Well if you want to bypass all the UI that does the processing for your raw data, the programming part will be quite complex. There are several ways to handle data BLE data, if the BLE is capable of acting as a Central and Peripheral role at the same time, you could possibly create a network of BLE modules talking to each other and use the raw data to suit your application needs.
Hope this helps.
P.s I have tried both the above methods as part of testing and they both work.
I started exploring openHAB for my home automation. Looks to be a great application for the home automation. I want to automate two homes and want to run openHAB on one centrally placed server. Is it possible to segregate the data for my two homes and provide use based access for two homes.
Or I will have to have to instances running on my server.
Please suggest if anyone has done this earlier.
you can (I believe) provide different sitemaps, but the most importing question is how will a central openhab instance communicate with the "other" home?
Especially If you're going to use bindungs which require a piece of hardware like z-wave etc.
You can potentially play with MQTT and have a small Raspberry Pi running in the "other" home feeding the MQTT.
Assuming that there is not a hardware or range based issue with using OpenHab for two homes (e.g. z-wave USB dongle but second home is out of range) and there is network connectivity between the two houses, there are a number of ways you can accomplish this. Here is one.
The easiest would probably be to just use a naming convention for your items and groups to easily tell which house the item comes from. You would probably want to set up a separate sitemap for each house as well. If I understand your question this should segregate the data for you based on name and provide use based access for each home.
If you want to segregate the data even more thoroughly you can configure your persistence to save all the items from one house to one DB and all the others to a different one, though you will need two different persistence bindings set up (i.e. one uses rrd4j and another uses db4o). I'm not sure this provides any advantage.
The final step is getting the data from the remote house into openHab. How this is accomplished will depend on the nature of the sensors and triggers in the other house. You can use the HTTP binding, TCP/IP binding, or an MQTT broker. I've personally exposed a couple of my Raspberry Pi based sensors to openHAB using a python script and the paho library that publishes the sensor data read from the GPIO pins to an MQTT broker and it works great.
Centralization vs segregation - you have to decide, which one has more advantages and less risk.
The two houses will store data on the server (openhab2, mqtt, DB/rr4d) and each one have access to it - that must be clarified.
The network connectivity is obvious, it should be stable between the two sites. Security is another issue - not only digital, but safety of life (hvac controlling or safety appliances with network outage?).
Configuration is pretty supported in both ways, separate config files (items, rules, persistence, etc) and connectivity in a hierarchy has endless approaches and capabilities.
In the newest version of the android app you can add multiple openhab servers. Why don't just use two instances of openHAB?