i want use lpc1768 to read and write to usb mass storage device
should i use this Fig30?
Fig30
or this Fig29?
Fig29
for reading and writing to USB MASS STORAGE DEVICE?
I'm asking about hardware design of it
The USB Mass storage device is obviously an USB device and thus your LPC17xx circuit must supply the +5 volts VBUS line. That is figure 31 in the datasheet.
But that also means you have to implement the difficult USB host in the LPC17xx, and SCSI for mass storage.
You could use figure 30 (OTG) if you needed to connect the lpc17xx itself to host like a PC.
Note that SD cards are much simpler to use (via SPI) in Software. And they can be faster: 25 MBit/s instead of 12 MBit/s via USB.
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I am currently using Webrtc to stream a game. It's a custom WebRTC implementation inside the game engine.
Both the client and the server easily support 100+ Mbps upload speed. Currently, i have locked the max bitrate to 80 Mbps, which is supported.
The issue happens when the webrtc probes for the connection speed, it drops down to 7-8 mbps then it slowly goes back up to 80mbps.
Which drops again when a webrtc-probing happens.
I have linked a video below of the issue.
https://drive.google.com/file/d/1coI3rrGVf4OAFnt2oeSCx0zFJznvfyQv/view?usp=sharing
What could the issue be and is there any solution to fix it?
I have a somewhat complex home network and I want to be able to monitor network activity both inbound/outbound. My network consists of 5 VLANs to segregate unmanaged network, user devices network, guest network, home automation network, and management network.
I have a ESXi server with 2.4GHz 8-c Atom CPU and 32GB memory. I have 2-c and 8GB remaining that I can dedicate. My 48 port switch is also managed.
I searched online and read various tools like Snort, Untangled, Sophos Home UTM, etc but I'm not sure if I need several of them, or just one, and how it will provide monitoring of my network to know if any suspicious activity is found.
Some extra features, but not necessary, would be to check mail (spam) and openVPN integration. I'd also like a daily report if possible to know how much inbound/outbound bandwidth was consumed. It can be emailed or viewed online.
I don't mind paying for a service, I can probably afford $100-$250 a year for annual subscription. It just has to handle multiple VLANs, and something like 80+ IP addresses.
I can't help you regarding monitoring for suspicious ativity, but for monitoring of the health of the network there are various tools.
PRTG is a Network monitoring tool which is free up to 100 sensors.
I don't know if they mean 100 host or if one host can consist of multiple sensors.
I don't really have any experience using it, but I know it is widely used for monitoring network health and bandwidth usage.
MRTG can also be used if only bandwidth usage is of interest.
HP NNM is another tool for monitoring.
It's very powerful and has alot of plugins (SPi). It can be used with HP NPS for statistics.
I know the have a free version for trail which should be limited to a number of hosts.
http://www8.hp.com/us/en/software-solutions/network-node-manager-i-network-management-software/
I have programmed a couple of MSP430x6xx microcontrollers to serve as Master for some I2C slave devices. One of the MSP430s transfer the data received from I2C slaves to a PC using its built in USB Module. I want to extend this to allow all Micro controllers to send data received from their respective I2C slaves to PC using a common bus system. Will it be feasible to use SPI for transferring the data from all MSP430s to a single MSP430 master(already serving as I2C master and USB device simultaneously) which then transfers it to PC? I would appreciate any other suggestions. Thanks
Yes, it is feasible we will have to write your firmware to handle this. You have to identify on the PC somehow from whom SPI/I2C slave it comes the data. So, your main MSP430xxx will do this adding some kind of header to the data saying the id of the slave device.
Is it possible to prorgramatically disable/ write protect the USB on MAC OS X ?. Also after a certain interval can it be enabled/ write be allowed. Any links/pointers would be appreciated.
EDIT -
I have been tasked to write a portion of software which will disable the USB drives on all the machines. This is for some customers who do not want their employees to take a USB and copy company sensitive information. But then for certain admins, the USB drives should get enabled by the admin.
It is my understanding that the write-protect tabs/switches on normally writable media physically disable the machine from being able to write to the media, so this oughtn't to be possible in software.
If you post more details on what you're trying to achieve, we might be able to offer some other suggestions.
For example, you might mount the volume as read-only, and after the time period has elapsed your software could change that to read-write access?
This functionality is already supported by the management frameworks on OS X. The simplest way to enable the restrictions would be with a Configuration Profile.
The drive policies only work with mountable volumes, so if you want more granular USB filtering you can use the iokit integration with launchd to specify things at a USB device level. Check this answer for more details on that approach. launchd LaunchEvents keys
I have some questions regarding communication over USB cable in Linux, in a Host-Target Device environment.(USB2.0) Please help as we are stuck for the below imiplementation.
We have a host PC connected to a target device (Linux OS) through USB cable.
On the target device we need to spawn 3 or 4 child processes. [Using fork() or some equivalent system call]
All the child process should communicate to the host PC independently though there own source file descriptor and sink file descriptors.
As per our experimentation, one process communicates to the PC at a time then the control is given to another process. But our requirement is for simultaneous communication. We are not sure whether USB driver(2.0/3.0) supports this methodology.
Any pointers regarding this will be helpful.
Thank you.
-AD
As per our experimentation, one process communicates to the PC at a time then the control is given to another process.
This is how computers work. Only one thread at a time has control of a particular CPU - when it blocks for i/o or exhausts its quantum, control is given to another thread.
What do you need simultaneity for that you can't manage with sending data one after the other?
USB is a serial bus protocol with a SINGLE DATA BUS, and this means, what you are looking for is not possible.
But we can have 4 different USB COMMUNICATION PIPES which can provide different paths, but NOT simultaneously.