My school project is doing edge detection on DE2 board.
I'm looking for the way to send bytes stream from PC to DE2 board, and after doing edge detection, send data out back to PC.
Any help on general ideas?
Based on the description of the DE2 on the Altera website you have the following IO interfaces on the DE2 board:
Built-in USB-Blaster for FPGA configuration
Line In/Out, Microphone In (24-bit Audio CODEC)
Video Out (VGA 10-bit DAC)
Video In (NTSC/PAL/Multi-format)
RS232
Infrared port
PS/2 mouse or keyboard port
10/100 Ethernet
USB 2.0 (type A and type B)
Expansion headers (two 40-pin headers)
Of these there are 3 that are probably the most suitable for your purpose:
RS232
10/100 Ethernet
USB 2.0 (type A and type B)
Which one to use depends on your bandwidth / latency requirements, reliability, what sort of software interface you need, timescales, previous experience and level of interest.
RS232 should be easy to get working, there are UARTs available on OpenCores that will get you up and running but the bandwidth will be pretty awful.
Writing some RTL that communicates with the PC via Ethernet packets should be pretty straightforward if you assume the network is always reliable. Clearly if you want it to be robust you'll need to look into adding some reliability layer like RUDP.
Communicating via USB is probably the hardest interface from both the RTL and software end of the interface, however if you have an existing example design than you can modify to suit your purpose this might be the best option.
One other possibility worth considering is to embed a processor the Altera NIOS II in the FPGA like and let that handle the interface to your host. You could run a full Linux instance or a bare-metal stack with a dedicated TFTP to transfer data around. There are various examples and tutorials on the web that will help you get started.
Related
People,
I have always seen references about how to use a SPI interface to operate a SD memory card.
This is not what I want. I need to do exactly the opposite.
I want to be able to use the SDIO controller (through SD slot) in my "host" (any PC having a SD-card interface) to talk to my devices (basically microcontrollers) that can only "speak" SPI.
If my understanding is not too wrong, I cannot simply tell my SD controller to talk in a raw SPI mode but I can teach my microcontrollers to behave as a SDIO device that can be controlled by my host.
This way I still have two challenges left:
Correctly implement a generic SDIO device in my microcontroller.
Implement/configure the correct drivers in the host to be able to interact with my devices.
Implement the SDIO device seems to be a matter of following the spec.
The host-side driver, though, is something I hope I can accomplish with a user-space driver in Linux using some already existing kernel-space driver to SDIO.
That's the point that I come to ask for help.
Can anyone please point me any samples, documents or any kind of resources that can help me in my task?
On the PC side, this is all you need: http://sourceforge.net/projects/sdio-linux/
This may be useful for reference: http://www.varsanofiev.com/inside/WritingLinuxSDIODrivers.htm (although, I don't think you would be writing a driver)
On the microcontroller side, use "bit-banging" to implement the SDIO spec.
However, first consider why do this. SDIO and SPI are just serial protocols, so is USB; wouldn't you rather make an SPI-to-USB bridge? USB is much more user-friendly on the host side, as well as being more standard/more common. And if you do want a SPI-to-USB bridge, turns out it already exists, the SPI Shortcut (probably other options, this is just the first one that comes to mind)
EDIT Or, you could bit-bang I2C on the micro, if the host supports I2C (many do). Actually, go through every serial protocol the host supports, and see if you can support it easily from the micro side (by bit banging, since the micro is likely to not have a slave mode for that protocol built-in). RS232 (with level shifter), I2C, and SPI are likely to be the preferred choices. SDIO is pretty much the last choice, I think.
SDIO is very tightly specified. Unless your microcontroller has an SDIO block that is designed to act as a device rather than host, I don't think this will be possible. I know of a few special purpose communications controllers that implement an SDIO device, but I haven't come across any general purpose microcontrollers.
You would need a fairly fast microcontroller to be able to bit-bang SDIO initialization at up to 400 kHz. If running an STM32F4 at 180 MHz, this gives you only microcontroller cycles between SDIO clock cycles. If the host turns up the clock speed to the maximum of 25 MHz after initialization, then you're down to 7 cycles between SDIO clocks.
For perspective on the SDIO spec, the one you linked is a simplified spec that doesn't cover the signalling and timing of the bus. The full spec is many times larger.
As Alex I mentioned, there may be better alternatives for what you need. If your SDIO host supports SPI mode, most microcontrollers do have SPI peripherals that can act as slaves rather than hosts, so this may be an avenue without a peripheral. If your data rates are low enough, a simple UART may suffice (you can reasonably hit 1 Mbit over short distances).
I trying to learn DMA for device drivers with PCI/PCIe devices, and my platform is linux/bsd. I have found quite a few simple PCI boards for training (such as simple digital I/O boards), but none have hardware complex enough to handle DMA. Is anyone on Stackoverflow aware of a PCI/PCIe card with some sort of microprocessor or mcirocontroller that I could program with open-source tools like gcc (e.g. PowerPC, 68HC11, Atmel, 8051, etc.)??
Of course the kicker is low cost...sub USD 300.00 if possible.
I DO NOT WANT an FPGA-based board, because that requires a Windows workstation (usually) for programming the FPGA, as well as all of the time required for creating and working with a PCI/PCIe IP core in the FPGA. Basically, I don't want to spend my time working on the FPGA; I want to work on the device driver! This may be my only option though...
If you don't want to use FPGA, then you have to find a board that has enough info for you to be able to communicate with the PCIe interface of it. Not that many boards come with HW interface document, but if you want or can do this without documentation, you can use one of these boards:
Alibaba 4 Channel MIDI GAME port 3D
Same board on E-bay Alternative 2 on e-bay
You can also get a bit more advanced board like this one, but then you need to know how to communicate with their chipset.
Alibaba 4CH PCIe HDMI Video Capture Card here
If you change your mind for the FPGA, I would really recommend the Altera PCIe board that comes with a reference design and the bit file already per-programmed on the board. It is much more expensive than those, but the biggest benefit is that you have full documentation of the PCIe interface:
Altera Cyclone IV GX Transceiver Starter Kit
Here is the info about their reference design:
Altera PCIe reference design
Hope you find what you are looking for here.
I want to implement a driver in Linux, that has a Ethernet stack but the data going out on hardware will be a serial port. Basically, I want to register my serial port as a Ethernet driver. Does anyone have any idea if this is possible?
I want to be able to push IPv6 and/or UDP packets out of the serial port and in a similar way receive the packets via a serial port and pass it up the Ethernet stack.
I do not want to use the solution of serial-to-ethernet convertors(external hardware that convert a serial port to a ethernet port) but have that in my PC itself.
I tried PPP over the serial port and it works well. I am also told that I can do FTP, HTTP etc using the PPP. Reference to this - http://www.faqs.org/docs/Linux-HOWTO/Serial-Laplink-HOWTO.html
I have tried to hack the code from a RealTek Ethernet driver with a serial driver but not able to gain much success. Rather I do not know the stack of either to actually do anything meaningful. Any advice, guidance or tutorials would be helpful.
Thanks
Aditya
You need to get back to de basics on networking, the way I understand you question is: "I have a serial port and I want to use is an Ethernet link". Sorry to crush your dreams but you don't have the real hardware to do so, I'll elaborate on it.
A serial connection is a physical connection that requires 3 wires (at least) tx, rx and ground. On the logical side you have an IC that coverts binary data into signals that are represented by discrete voltage ranges.
Ethernet is a layer 2 protocol, the layer 1 is provided by the technology used to transmit the signals (coax, up, fiber etc.) As you might see by now, you need a different set of hardware to convert the logical Ethernet frames into a stream of digital numbers, in fact this is call framing.
Since Ethernet has been an easy to use protocol it has been implemented as e preferred protocol for many network operators, of course one of the biggest is PPPoE where you have a PPP session over an Ethernet link. Of course this won't work with your example neither since you're trying the opposite.
If you're just learning and have all the time in the world you can attempt to write your own Ethernet framer over serial lines. This means you need to implement IEEE802.3 into the driver and then you need to serialize the data to push it as a stream of bits over the serial line. Of course note the following drawbacks:
Your driver won't be able to fully support Ethernet, you need some support at hardware level to implement some signaling (example, auto negotiation, CSMA/CD, etc)
You driver will be pretty much useless unless you back in time where 115.2kbps is top speed in data transfers
IMHO there are more exciting projects that you can pick up in the networking field for device drivers. You can for example attempt to buy a NIC and develop the device driver for it from scratch and you can optimize certain areas. Finally, remember that most of the Ethernet implementations are now done in hardware so you don't have to do anything but filling a few registers on the MAC and voila!
SLIP and PPP do already what you want.
I am working on a project where I need to attach a sensor to the computer like laser sensor or an infrared sensor, to use in a foul line detection. Basically the idea is, if someone steps on the foul line, the laser or infrared will be blocked by person's foot, and the laser/infrared won't be received by the receiver, causing the sensor to send a signal to the computer.
The problem is, I don't know where to start something like this. How would I go about attaching a sensor to a normal computer (like a normal PC that we use)? If someone could direct me into a direction or has any inputs, that would be really appreciated. Thanks a lot!
You may want to look at Arduino (http://www.arduino.cc/). It is an open-source microcontroller that can be used along with a computer and is designed to be hooked up to various types of sensors. It also has an extremely helpful, active support community.
There are several approaches to the task of bringing the sensor signal into a PC (to take advantage of PC's computing power, good user interface, connectivity to the web).
Look for integrated sensors that have an interface for attaching to a PC (RS-232, USB, Ethernet). For example, you may find something useful by googling photodetector USB.
There are I/O (input/output) devices for PC. They have analog and digital inputs and outputs. Look up LabJack, National Instruments USB-6008 and dozen other types of commercial USB I/O boxes.
Connect sensors to a microcontroller (uC), then connect uC to the PC through a USB or RS-232 or Bluetooth (the list goes on). This involves more hardware. You'll need to write firmware for the microcontroller too.
Obviously, which approach to choose depends on your skills (or willingness to acquire new ones), timing, budget, team structure (if it's a team effort).
You could use a photo-transistor and a Yocto-Knob. The Yocto-knob is an USB device able to quickly detect resistivity changes, you just have to connect the photo-transistor to it. Here is an application which looks pretty similar to yours: they use a light barrier to detect and photograph a fast object:
http://www.yoctopuce.com/EN/article/how-to-drive-a-camera-shutter-automatically
I'm looking to implement the Bluetooth protocol over a physical Wi-Fi based transport, if that makes sense.
Basically my phone has Bluetooth, and my laptop has a Wi-Fi card (802.11a/b/g).
I know that Wi-Fi operates over the range 2.412 GHz - 2.472 GHz, and that Bluetooth operates over the range 2.402 GHz - 2.480 GHz.
I couldn't help but notice the overlap here. So my questions are:
What sort of low-level APIs would I need (preferably in C, on Windows) in order to send a signal out at certain frequencies on the Wi-Fi card?
Would I be able to implement a Bluetooth stack on top of this?
So basically, can I transmit Bluetooth using my Wi-Fi card as essentially a radio transmitter?
Thanks
Implementing the Bluetooth protocol over a physical Wi-Fi based transport does make sense!
Bluetooth high speed (v3.0) defines the possibility to use alternate MAC/PHY layers, known as AMP feature. The L2CAP and higher layer protocols from Bluetooth can be transmitted over a Wi-Fi MAC/PHY layer rather than a Bluetooth MAC/PHY layer with a resulting higher throughput. Some products are on the marked supporting this - look for 'Bluetooth High Speed', AMP or Bluetooth v3.0 support.
No, you can't do this. Bluetooth devices are typically wrapped up all in one chip. Plus, they use completely different modulation techniques. No low-level anything is going to allow you to transmit anything different, unless you are flashing the device. Even then, it may not get you much closer.
Bluetooth Modulation Information:
http://www.palowireless.com/infotooth/tutorial/radio.asp and http://classes.engr.oregonstate.edu/eecs/spring2003/ece44x/groups/g9/jon_gillen/white_paper_jon.pdf
About the only thing you can share between WiFi and Bluetooth devices is the antenna. (Assuming only one device is using it at a time... don't blast 32mW into the receiver of the other radio!) The radio itself is all wrapped up into the same chip. The same is generally true for WiFi.
Bluetooth and Wifi have different phy layer protocols and thats what is coded into their chips, hence you can't use one chip to transmit packets of the other protocol.
Moreover most of the chip vendors, do not expose any RF logic.
Technically yes but there are some things to consider such as the pre existing coding on the chip and if the chip can support Bluetooth coding as well as wifi coding, I mean if you have two separate wifi chips go ahead and try but be warned I tried and nearly killed my computer because of preexisting copyright protection coding on other parts of my pc that prevented any programs on the chip from starting until I reset the chip to factory defalts.