Also which protocol should I research about for the data transmission between the software and hardware?
How will the software receives the signals from the hardware to read cash deposits?
I am reading about the rs-232 protocol but am unable to move forward with it? can anyone give me some suggestions or the flow to move forward?
Related
I have a question regarding ESP32 wireless interfaces.
Long story short I gotta do master research and I'd like it to be about ESP32 Wi-Fi + BL/BLE. My supervisor suggested we could make use of EMC chamber available on my department building and measure how well ESP deals with electromagnetic interference during transmission (ESP to ESP via Wi-Fi, BL, and BLE as I mentioned).
The problem is that we gotta make it dependent on some changeable parameter. First, I thought about using various protocols but in longer run, it doesn't make sense. Then my supervisor suggested changing for example MTU. I did a search and found how to change it for BL but can't find how it can be done for Wi-Fi.
Does someone have any idea how to modify MTU for Wi-Fi in ESP and what else I could change to influence electromagnetic resistance anyhow?
Is it a reasonable subject?
Maybe as a society that knows ESP well, you can propose some other interesting idea for research?
Thanks for the time and effort!
Can we broadcast Music using wifi broadcast and listen to thhe same on devices supporting monitor mode.
I would like to listen on monitor mode because I expect the number of devices getting connected is too high for wifi to work properly using IP-protocol.
I want the wifi device to act as a FM broadcast where every device recieves every packets and stream the music.
Are you talking about this Wifibroadcast , here?
If so: well yes, monitor mode is the underlying technology, as can be seen here.
Now, if this is about doing a commercial product, sadly, you cannot expect any kind of interoperability from this.
Streaming audio/video over Wi-Fi is a business, and the the power in charge (Wi-Fi Alliance aka WFA) as some view on it, including certification programs. Have a look at Miracast, using Wi-Fi Direct.
As for multicast / broadcast, it is even more of a business and the realm of proprietary technologies for now (example here - and no, this is not limited to automobile). This is quite complicated, to start with because of the synchronization problem across receivers: you don't want 2 radio receivers in the same room to play with a 1 seconds delay, this would be cacophony.
EDIT:
Meaning, be it with the Wifibroadcast OSS project or with the proprietary industry about it, since there is not yet an open protocol for this (as "publicly available standard specification", I don't even go about implementation, FLOSS or not), you will have to provide a specific application for every receiver to match your broadcaster protocol, and vice versa. And that is the state of the industry today. That is what the company I mentioned above, or this other one more well know, or these are doing. And so, they do not interoperate. This will be your problem: provide a receiver app for Windows, Mac OS, Android and iOS (where you may not even have access to sub-layer 3 API) that will match your radio broadcaster protocol. And Linux too, please.
Though, this is the direction of history because this is what the user wants: stream A/V to/from device/application X from brand A to device/application Y from brand B.
And so people have been working on this, on layer 2, because layer 3 and above have unsolvable challenges with it, at IEEE since 2004 with Ethernet AVB, which is a set of protocols. You can download some of its standards for free, others for a moderate fee depending on how old they are. There is a SIG taking care of certification(http://avnu.org/certified-products/) to guarantee interoperability.
It is for 802.3 (aka wired Ethernet), but there is some work done to bring this to 802.11 Wi-Fi. Because again, that's what the user wants, the market is here, no question about that. It will take a long time. Even more to get consumer electronic grade devices or applications of the shelves. But they will interoperate out of the box, that's the goal.
There's even been work done on moving this to layer 3/IP as well BTW, with some performance sacrifice.
So come back in a few years, and all should be setup. Or, if you have lots of time and money and no urge to deliver, implement a solution based on these standards?
PS:
Link to AVnu (Ethernet AVB SIG) page about use cases for consumer electronics audio streaming, wired or wireless:
http://avnu.org/consumer/
...and its 10 pages white paper at the bottom of the page.
I am currently working on a project for my university course. I am design a device which will be an intermediate interface between the computer and a USB flash drive, i.e. data go from computer->my device->USB drive.
One of the functions I want on this device is to be able to detect if there is any data activity going on, and send this information to the microcontroller. I don't need to know anything about the data itself, just whether there is data being transferred.
I've done some research online about how USB works, but I can't seem to find a good way of doing this. I have spoken to a tutor at uni. Apparently this is "very easy" to do, but I don't really know how. Can anyone suggest some ideas? Thanks very much.
In this case the simplest way is to use additional soft which can log USB protocol as well as a microcontroller, like USBlyzer (http://www.usblyzer.com/) or USB data capture (http://www.eltima.com/products/usb-capture/)
You need to insert your flash drive to device which is plugged to USB port in your computer. Then run USB data analyzer software and find the USB port. That's all! After that you can monitor and analyze all data between microcontroller and the app. Moreover, you can save and export captured data
Your tutor not quite right.
USB bus always have activity, even if no data transferred.
Carefully read USB specification (http://www.usb.org/developers/docs/), especially 'Protocol layer' section. Some basics you may read in 'USB in a nutshell' article.
Explore bus with oscilloscope.
Also you may use software analyzers like http://desowin.org/usbpcap/ or http://freeusbanalyzer.com/ to explore data on bus.
I think, will be enough to capture all packets on bus with external microcontroller, measure their duration and sort waste SOF packets and valuable data packets.
Sure, your microcontroller must be fast enough, to keep pace of USB 2.0 bus. Detection of activity of low-speed devices, like keyboard, will be much simplier, and may be done even with arduino.
You are trying to make a protocol analyzer like catc http://teledynelecroy.com/protocolanalyzer/protocolstandard.aspx?standardid=4
These is a device which is like man in middle for any network.
You would need your device to act as USB host(master) and USB device(slave) at same time. Also while copying data from one port to another you need to make a data copy for analysis. USB devices have critical timing requirements and operate at high data rate. So you might need good amount of processing power in your device. Also this makes such analyzers expensive.
If there is no requirement for analyzing USB protocol, you can have device that will analyze slower buses like uart,spi I2c etc.You can check hobby manufacturers like sparkfun for such tracing devices.
Best luck with your endeavor
I want to find a solution to broadcast voice over WiFi for the people in a march. Since Android and IPhone is the most popular devices among the people in the march, it would be great if i can find a solution for audio broadcast over wifi with limited budget.
I know that people in occupy movement use different app on their cell, but it is not suitable in a march in my city. As the authority in my country may temporarily shutdown the data over mobile network to disable the app.
If i can develop an app to gather the broadcast message (SSID) from a powerful wifi AP with a long-length directional antenna, I should able to deliver message among the people in the march. Is it a possible solution?
Also, is it possible to modify the AP to allow any device to join the AP without further acknowledgment and broadcast message to all devices in that network?
Any idea or opinion is welcome.
Many Thanks.
This will be difficult, especially with a large number of users. Since you only need to send audio in one direction, that will at least be a bit easier.
First, you're going to want to put that AP in the middle of the crowd with an omnidirectional antenna. Perhaps, in a backpack or something. Each phone on that network needs to "hear" when other phones are transmitting, or it will be a mess. Even though your application is one-way, 802.11 isn't.
Now, when you write your application, use UDP packets sent to the broadcast address. No need for TCP packets, as they will clog up your network anyway.
Use a simple voice codec, such as AMR. The codecs available vary from platform to platform. See this document for a list on Android: http://developer.android.com/guide/appendix/media-formats.html
Honestly, the easiest solution would be to go buy a small FM transmitter, since many phones have receivers in them anyway.
I've been trying to find a tool for monitoring my home network. Before I go into the details, I've looked at a ton of different software and they're either an overkill or don't have what I'm looking for. Hopefully the community can help me with some advice.
My network is quite small. It consists of a modem connected to a D-Link DI-524 router. To this router I have a number of computers hooked up wirelessly.
What I'm looking for is a lightweight tool for monitoring my traffic. The ideal tool would have a GUI that shows an icon of the router, and icons of all devices connected to the router with a bandwidth indicator on the lines connecting the nodes. That's pretty much it.
I'm not sure if my router has SNMP. This might be a dealbreaker since many of the cheaper routers don't. I've also read somewhere that many routers can be monitored over UDP.
Found tnv after quick googling.
tnv (The Network Visualizer or
Time-based Network Visualizer) depicts
network traffic by visualizing packets
and links between local and remote
hosts.
Here is a list of good tools to monitor network activity.
Looks like MRTG was the best tool to use
I have also been pleased with the Serial and USB software provided by HHD Software. I've never used their Network version, but if its as good as the USB and Serial, its probably pretty good. Here is the free trial version.
you can use CACTI and Mikrotik DUDE.