I have one project to do.
I need to transfer photos from camera to PC, i need to use SDcard interface it is SPI i hope ).
Because usb transfer is not in option, so i think that i connect some microcontroller or raspberry pi instead of sdcard and emulate sd card and from microcontroller i somehow send it (via usb or ethernet)to pc. this whole operation (wrom camera to pc) must be realy quick (1-2s) and photos are 2-4Mbyte. Do you have any tips how to do that or what microconroller chose?
scheme:
SPI as SD emulator USB/Ethernet
|camera|--------------->|microcontroller| ---------------> |PC|
thanks for advices and ideas.
Related
we are doing a project for receiving data from a device using a RS232 to ethernet converter (gridconnect net 232+) onto to a Atmel board. When we connect the converter to the PC, we are getting the output but not when connected to the microcontroller board. We need to know if there has to be some network confirguration to be done on the converter in order to receive it on the microcontroller.
Thanks !
I haven't worked with that board or device, but with any RS-232 communication channel you should check that all RS-232 parameters are set up correctly on both sides. Databits, stopbits, parity settings, etc. Even one setting being off will completely stop RS-232 communications.
Once that is done, I'd hook up a terminal emulator of your choice to simulate the microcontroller side and make sure that you're getting the right traffic from the Ethernet side. You might get lucky at that point and everything might start working. ;)
Articles on this topic from 2012 for earlier RPi hardware extolling the virtues of using an external USB flash drive are now dated.
In 2015, using Raspberry Pi 2 hardware, is there still any advantage to moving the root file system and booting from an external USB flash drive instead of just using the default microSD card?
I'm not sure if the raspberry pi bootloader is even capable of booting from USB, but I could be mistaken (there might be a way to set up an SD card to act as an intermediate step in mounting the OS from USB).
Aside from that, I can't imagine you'll notice much of a speed difference between the micro sd and a USB 2 flash drive (as far as I'm aware, the rpi doesn't have usb 3 hardware). Both will have similar life span.
Other considerations: power consumption (I believe SD has an advantage here, especially since a card will have to be used anyway to boot), quality of either device (you can buy really bad SD cards and USB flash drives alike)
I would be interested in seeing some bench marks if you decide to run any tests to see if there's a difference.
My DriveSpeed benchmark measures speed of large and small file writes and reads, plus random writing and reading. RPi 2 results for SD and USB drives are here.
http://www.roylongbottom.org.uk/Raspberry%20Pi%20Benchmarks.htm#anchor21
For booting, you need to establish which performance feature is more important and it is not just large file data transfer speed. Anyway, it mainly depends on the drive hardware performance characteristics. My system SD card can be out performed by SD cards in a USB card reader.
In the last weeks I experimented with my Raspberry Pi B and with the PiCamera. I had the idea to establish a connection between the RasPi and an Android device or (if it is easier) to a windows notebook without an access point in between, just like the GoPro camera and its App. I would like to have a live stream from the PiCamera to the other device and the possibility to start/stop recording a video or simply take a picture.
The app itself is not my problem, I wrote some simple apps before. But I didn't yet find a tutorial or description how to set up the communication and the stream.
I bought a WiFi dongle (Fritz!WLAN Stick N - by AVM) that supports WiFi direct and my phone (Samsung Galaxy S5 mini) does as well.
My first question is how to set up this stick on Raspbian - yet it is not recognises as a wifi dongle, and the second is how to achieve what I descriebed above.
Could anyone please describe what I can do?
Thanks in advance!
PS: I prefer a description for bash because I use SSH
So far, what i tried is that
put raspbian image on to SD card.
power up PI with Sd card.
And after booting, a set-up option window popped up which i can't skip without keyboard.
Is there any way to skip this option menu ..?
Thank you
No, there are no buttons or physical input on the Raspberry PI itself, so without plugging some input device in you cannot skip the menu.
You could install Raspbian on a Raspberry PI emulator, do all the setup on your computer, then copy the already-setup disc image to your SD card. Here's a tutorial for setting up QEMU to emulate the Raspberry PI (and it includes installing Raspbian on the emulator): http://xecdesign.com/qemu-emulating-raspberry-pi-the-easy-way/
That seems like a lot of work though. You should probably just borrow someone's keyboard.
Is there a way to make sure that SD card of Raspberry PI works only with particular device only?
I do not want anyone to use the SD card with any other Raspberry Pi device other than specified.
Is there a way out?
There is no simple way do do this. Of course you can build some trickeries based on Device Informations (fsys and udev) and crypt your disk. But, it is clearly impossible to guarantee system integrity when the storage device is physically reachable: anyone can mount it and some aware/clever guy, using enough time and effort, shall reverse engineering it.
See this guide for Arch linux: https://wiki.archlinux.org/index.php/Disk_Encryption
If you encrypt your filesystem only he have the password can decrypt the sdcard. This prevent unauthorize access for example from the Windows/Linux to the sd card files.
But if you boot from the PC you are in the same problem.
The only thing that comes to mind is to make a script that controls a device that exists only on raspberry is available and if not, automatically encrypt the system.