I'm trying to simulate a wireless network with 3 access point. I need to set the range of each AP and simulate mobile devices walking around these APs that are sending wireless sign.
I read that a good omnet framework to do so is the INET. I already ran some examples and tutorials but I still cant't do my experiment. Does anybody knows a step by step tutorial to simulate an AP sending sign for a mobility device?
Googled for resources for INET and following these,
http://rockthevoid.tumblr.com/post/17374133262/omnet-and-how-to-create-tcp-applications
https://omnetpp.org/doc/inet/api-current/tutorials/wireless/
Related
for a simple project, I need a cheap wifi device, which can be used as Wifi repeater. I need also the possibility to include own functions (e.g. send own put/get requests to www from device itself).
I found a library to use esp32 as a nat-router (https://github.com/martin-ger/esp32_nat_router), but this seems to be a deep hack and it is too "advanced" for me.
Therefore, I looked for an alternative device.
Is it possible to use Raspberry Pi Pico W as wifi repeater using micropython?
E.g. Raspberry Pi Zero supports AP_STA mode, but I have to consider the costs.
Thank you.
What I did until now:
Research about esp32 as router, but no solution with Arduino or Micropython found. Tried to understand esp-idf code from above git, without a chance to extend with own www requests.
About Raspberry Pi Pico W, I found some examples only with single use in AP or STA mode.
Hey I am building an embedded linux device using Yocto, that will transmit some data via GSM network. It will work in a rough conditions, poor GSM range, so it will switch SIM cards often to find the best network.
My question is - does the modem manager rewrites the current APN during each sim card switch? Or does it use already saved?
I am asking this, beacause I witnessed GSM modems' flash being killed after like 3 months, because of APN being rewrited on each network switch.
Thanks!
My issue is fairly simple to describe but I have no idea what the problem could be. So I got my FONA 3G and immediately after taking it out of the box, I connected the battery and I wired up my FTDI board (aka USB to serial converter), and then I plugged it into my USB port to try and establish communication. I just tried the most basic at command AT(using PuTTy). You're supposed to get an OK in response but the FONA doesn't appear to even notice that I'm trying to talk to it. I type AT and press enter and nothing happens at all.
The issue is most certainly not my FTDI board, I'm very experienced communicating with wifi modules and other GSM modules using PuTTy. So please don't be concerned with the setup. That's 100 percent definitely not the problem.
I was able to send AT commands after plugging the module into my laptop directly using the module's USB input, but there is still some issue with its UART. I haven't been able to send or receive any communications directly from RX and TX. It wont respond to any programs I load up onto my arduino. Its like the UART is asleep.
If you have experience with FONA 3G, please speak up and tell me what steps you took to get the UART to respond. What should the status indicator look like before its ready to receive commands? Any knowledge you have about the FONA3G module would be helpful.
As a side note, the FONA3G has a chip number. It is SIM5320a. I don't know if that helps. Most people know it as FONA 3G.
All right. Thanks to those of you who posted comments. It turned out to be an issue with the baud rate! Its always the simple stuff. Adafruit said this thing has auto baud meaning you can use any baud rate but they are wrong. It requires 115200 to work properly. Also I'd like to point out that there was nothing wrong with my setup. Sometimes you should trust the person when they say their setup is 100 percent fine.
I have a piece of equipment at work that has a USB output, that then requires to be connected to a specific USB-to-Ethernet adapter in order to send TCP packets. I am trying to cut the Ethernet adapter out of the equation, and connect the USB output directly to the computer.
A Windows machine does not detect hardware changes when it's connected, so I'm thinking about using a Ubuntu device since it might have better network tools.
What are the ways I can test the device to figure out what it actually is? Is it even possible to remove the adapter from the equation in this situation?
PS. The device is a very specific ECU used in cars. It is not something I can download drivers for. It also uses a Class C IP address.
I'm looking for a very specific USB device for debugging systems that may use USB but not with a regular computer (proprietary hardware). I want a device that has a USB host controller and two USB device connections. The device to be debugged is connected to the USB host controller and one of the device connections is connected to another device with it's own host controller on it. The the other device connection is connected to a pc. The point being that all USB data travelling through the device (from the device connected to the host controller to the device connected to the first device connection) is reported to the pc.
I'll happily write software to do the logging (in fact I want to) but I can't seem to find a board like this anywhere. Can anyone help?
I have an Ellisys USB analyser, which isn't exactly what you describe internally, but does sit between a peripheral and a host and use a separate PC to collect the data.
(i.e. it has two 'B' and one 'A' connectors on it.)
Excellent product, and very helpful company.
Sniffing the USB shouldn't be too hard if you have the right hardware. And that is the tricky question. I haven't seen anything that describes the USB breakout box that you want. However I can say that this is in the realm of the following two magazines:
Nuts and Volts
Circuit Cellar
If they don't have a USB breakout box project in their archives, then at least they will have advertisements for small cheap single board computers that would have multiple USB ports that you can use for buffering the signals and reporting it back to your PC.
Alternatively is it possible to just wire your PC up to the middle of your two devices and write a custom drive that echos data back and forth while sniffing off a stream for you?
Sorry for the long delay in my reply -- I checked out one of our USB developer's toolchain, and he uses a Beagle USB Sniffer. He seems happy with it.
You're looking for a USB device with two upstream outputs. I think according to the USB spec, this is not possible. You will have two USB hosts trying to send messages and control the USB devices at the same time.
What if you were to look for a device which allowed you to view the data going through a hub via something other than a usb output?
If you're building something custom, take a look at this USB chip site. The chips are programmable via a windows application. Once you define how you want it to operate, it's saved on an EPROM on the dev board ($30-$50).
Sorry if this isn't helpful!