Virtual phone line simulator - simulator

I am going to write an IVR system, and I wonder if there is a phone line simulator.
What I mean is a software which creates some virtual devices which act like a voice modem or an Analog Telephony Card, and simulates some random or periodic calls through this virtual devices.
I have searched the net, but unfortunately I was not able to find something useful.
Does anyone know of anything?

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Need help for a deeper understanding of BLE

I have to write a BLE application on an embedded device and there are some features where I'm not sure if BLE supports that or whether I've to create some wrapper around everything or if it's maybe not possible at all. The gerenal descriptions of Bluetooth and BLE I found around the internet usually only cover the overall functionality but don't go in too much detail. If this post gets too complex I'll split it up into different smaller ones.
I use the STM32 BlueNRG-MS chip
1. Discoverability (resolved)
The user has to be able to disable the BLE function in case there are several devices in reach. I see that there are functions aci_gap_set_discoverable() or aci_gap_set_non_discoverable() but altough I set it to not discoverable I can still see it in the LightBlue App on my mobile. How would I correctly disable the BLE functionality of a device to make sure no one can see it or connect to it?
Update: Okay that has been a mistake from my end, if I call the aci_gap_set_non_discoverable() function it is actually undiscoverable. So that's fine.
2. Only accept connections of paired devices
I'd like to achieve a behavior such that, if you have an unpaired phone you have to set the BLE device into a pairing mode in order to connect. If the phone has already been paired, the BLE device shall accept the connection request regardless of whether it's currently in pairing mode or not. Is this what the whitelist should be there for or do I have to do this manually by saving the address of the device after successful pairing? If whitelist is the right approach, I read that newer phones cause issues with whitelisting because they change their address on a regular basis, how can I handle this? That's actually where I thought I'm gonna work with the "discoverability".
3. Automatically reconnect
I'm not sure if this topic has to be handled on the BLE device or on the mobile phone. E.g. my phone is paired with my car's radio, so whenever the phone is in the car it automatically connects - how is this done? It's still the phone that acts as central device I assume?

How do I program this BLE location tag?

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

How can multiple smartphones connect to a mcu at the same time?

I'm having the hardest time to get the solution of the following problem.
Main issue:
Several smartphones(up to 30) must communicate with a MCU at the same time.
System overview:
There are many rooms(each room is a cabinet that 30 people can go into), and every cabinet will have one MCU for the smartphone users.
MCU will control some device of the cabinet.
The scenario of this system is as follows:
1. The users go into the cabinet.
2. Smartphone app will recognize the MCU(or MCU will recognize the smartphone) and the MCU will send some data to the smartphone and this data will be noticed to the user.
3. User inputs some data at the smartphone app and this data will be sent to the MCU to control the cabinet device.
4. Up to 30 people can go into the cabinet at the same time and the system should handle all the users simultaneously.
I'm going to develop smartphone application and MCU firmware for this system.
My thought:
I'm thinking to use Arduino/RFduino/Raspberry Pi as MCU and I'm thinking to use Bluetooth LE/Wifi/3G as communication material.
I've tried the following solutions
1. Using bluetooth low energy on Arduino/RFduino/Raspberry Pi.
MCU will be BLE peripheral and my smartphone app will be BLE central.
But I found that a BLE peripheral can only be connected to a BLE central at the same time so I can't use this method.
2. Using wifi on Raspberry Pi
I think that Raspberry Pi can run web service and my smartphone app can communicate with the server through http.
But every time the smartphone user go into the Raspberry Pi based wifi-zone, the user should select the wifi-hotspot at the network setting if he registered this wifi already, and the user should register the wifi-hotspot if this is the first time at the wifi-zone(cabinet).
This is very inconvenient for the users so can't be used for me.
3. Using 3G network on Raspberry Pi
Unfortunately, there's no 3G signal in the cabinet so I can't use this method.
I'm looking forward your kind answer.
Any hints or comments will be welcome.
Thanks for your attention.
Thanks for your answer in advance.
Toltori Kim
Well... I'd go with wifi. And QR codes.
I'd make either a single wifi network for all the cabinets (so only one set of credentials, or even an open one - without security) and then the app can connect to the raspberries using a sort of authentication (where the credentials are written in a QR code inside the cabinet) or a wifi network for each cabinet and its credentials are written in a QR code.
I'd use the first one, maybe without security. So the user has just to go in the cabinet, connect to the common wifi, make a photo at the qr code and then can use the RPi

USB Host Mode solution for Motorola-Droid phones

I would like to control an Arduino device with a Motorola phone.
I have a Lilypad (preferred), an Uno, and a Mega Arduino board and I have two Motorola phones (a Droid Bionic and a Droid Razr Maxx) both running Android 4.1.2. According to an App called "USB Host Diagnostics" neither phone has USB Host Mode capability.
A variety of sites suggest the problem is that the phone doesn't provide enough power to the Arduino. Their solution requires cutting up and reconnecting the wires inside the cables. Others say the creation of a special "dongle" solves the problem, as long as it is in the phone when it starts to boot up but is removed before it finishes. Others suggest that it requires rooting the phone, which I'm afraid is probably beyond my comfort level and skill set. And many of these postings are several years old.
Has anyone figured out an smarter/better way to either enable or work-around the host mode capability issue of these phones? Or would it just be easier to find a used Nexus or Galaxy phone?

Communicate my cell phone with my laptops in cell phone frequency?

Every communication that is made without cable, everybody can listen but not everybody can understand. So, when I call someone with my phone, or send a sms my cellp phone send information, I want that my pc know this (I know that both have to the same frequency). Or some site or material to start with it. I have an android.
It's like make a operator communication, just that is my cell phone with my pc and not my cell phone with the operator
Please have a look at OpenBTS. It is an (experimental) open source implementation of a BTS (base transceiver station), the network node that handles the radio communication. Similar OpenBSC.
What you want to do is huge. You will need special hardware.

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