I am using Sky/Telos and Contiki-OS in one of my project to transfer images. I am trying to broadcast an image from a node (connected with PC) so that other nodes (Connected with PC) are able to capture the image and rebuild it.
Any suggestions will be very helpful.
You could try CoAP block transfers. Give examples/er-rest-example a try; specifically look into the "chunks" resource.
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I'm trying to stitch two images on fpga using xilinx zedboard zynq7000. I couldn't find any material on how to dump two images onto the board and then get the output placing the images side to side. Any leads are greatly appreciated.
That board has arm processors, typically running linux. So at least you won't have any problems in getting images into the board, either with gigabit ethernet, or on sd card, or on memory stick in usb otg port. You don't really want to implement that channel yourself on fpga side, it would be just a waste of time.
To process images using fpga part (assuming that's the point of the task), you'll have your fpga-hw part connected to arm system via AXI interface, and memory-map it into linux application's address space.
You don't need entire images saved into fpga hw memory blocks, as probably pics will be too large to fit into available fpga resources, and because fpga can access linux side memory (big sdram) via fpga-to-sdram bridge.
I'm doing an image processing project on Zedboard Zynq evaluation board, using the FPGA built on it. I have written the image processing block using HLS and created the IP with both input and output as AXI4 streams with width 8.
How do I read a JPEG image on my PC and send it as an AXI4 stream to this IP block, and output it back to show it on my PC screen ?
Are there any existing IPs which accomplish this ?
P.S. The FPGA board is connected to my PC via JTAG cable, in case it's relevant.
The exchange of image data between the programmable logic (PL) and the processing system (PS) of the Zynq, can be established using direct memory access (DMA)/video direct memory access(VDMA).
This functionally is provided by Xilinx as an IP core. This IP core implements the receiving and transmitting of image data on PL side as an AXI stream.
On PS side the DMA can be made accessible by using the linux UIO. For this purpose you have to modify the device tree node of the DMA IP core in the device tree of the ARM core. If this is done, the DMA is available under /dev/ in the linux system.
Now it can be mapped to the user space using mmap(). By configuring the DMA, a memory area in the RAM of the PS has to be assigned to it. This memory area is used to implement a so called stream buffer. The DMA core uses this stream buffer to read or write image data. At the same time a linux application can access this memory area. This allows exchange of data between PS and PL.
A detailed description of the individual registers and the configuration procedure can be found in Xilinx's AXI DMA/VDMA product guide.
As far as the image data is available in the user space, the Ethernet connection could be used to send the image to the host PC. The JTAG connection is not the proper way to exchange image data between a host PC and the Zed board.
I would like to know is if is possible to send data from my stm32f103 board to my laptop using usb-ttl pl2303. I have tried but even after downloading the drivers the com port is not recognized by com terminal applications.
i think i found the solution, for others who might be in need, u have to backdate or roll back the driver .you do that by downloading old driver packages .
I am a newbie of the Contiki System. I am trying to upload binary data (in
txt. format, it is some recorded interference) to the TelosB node to regenerate
interference (the data file is in large size, 5M for example), in other words, I am trying to use Contiki to read binary files and send to the node. I googled
this problem, but did not found much useful information.
Could anyone give me some idea?
Thank you in advance.
The easiest way to send data from/to your TelosB is to just send it to the tty associated with the USB port it's connected to (e.g., /dev/ttyUSB0). Your TelosB will be able to simply read the data from stdin (and vice versa).
Is there a way where I can manually download a docker image?
I have pretty slow Internet connection and for me is better to get a link of the image and download it elsewhere with better Internet speed,
How can I get the direct URL of the image managed by docker pull?
It's possible to obtain that, but let me suggest two other ways!
If you can connect to a remote server with a fast connection, and that server can run Docker, you could docker pull on that server, then you can docker save to export an image (and all its layers and metadata) as tarball, and transfer that tarball any way you like.
If you want to transfer multiple images sharing a common base, the previous method won't be great, because you will end up transferring multiple tarballs sharing a lot of data. So another possibility is to run a private registry e.g. on a "movable" computer (laptop), connect it to the fast network, pull images, push images to the private registry; then move the laptop to the "slow" network, and pull images from it.
If none of those solutions is acceptable for you, don't hesitate to give more details, we'll be happy to help!
You could pull down the individual layers with this:
https://github.com/samalba/docker-registry-debug
Use the curlme option.
Reassembling the layers into an image is left as an exercise for the reader.