I am trying to learn Linux by following instructions in "Mastering Embedded Linux Programming" by Chris Simmonds. By following the book and with some help from Stack_Overflow_1, i was able to build the MLO and u-boot.img.
However, when i connect USB cable to my PC and execute the ls /dev/tty* command, i cannot find any device with /dev/ttyUSB. All i can see are devices with /dev/tty0-63, /dev/ttyS0-31 and one /dev/ttyprintk.
Also, when i press down the S2 button and connect the USB cable, i can only see the power led glowing and nothing else.
I have properly built the u-boot (three attempts to get it right).
Also, as per the instructions in the book, i am only testing the u-boot stuff and yet to reach the kernal part.
If i remove the sd card and connect the USB, im an able to talk to my BBB over ssh (192.168.7.2).
How to i get the u-boot to work? Thank you!
If you don't have one yet, I'd recommend to get a USB-to-serial device (3.3V Vref). You connect it to the debug UART (J1) which is located next to the P9 side. Nowadays those are very cheap and can cost below 1$. Ones that feature a genuine FTDI part will be 5-10$ at least.
The serial port you are referencing is only available once the device has passed through U-Boot, booted the kernel and finally userspace has set up the communications.
Especially when working with U-Boot and the Kernel, low level UART access is crucial.
As a further note, could it be that the Book refers to the (white) original Beaglebone? That has a FTDI USB-to-UART chip on board and will allow you even U-Boot access. You can do the same things if you have the above mentioned USB device.
https://groups.google.com/g/beagleboard/c/eNDjK05spY8/m/GPvhcP52BAAJ shows that one needs to hold the space key to enter u-boot.
Also, the info. here might be more up to date compared to the book.
https://www.digikey.com/eewiki/display/linuxonarm/BeagleBone+Black
There is no way to copy and paste everything from the eewiki. I just left you the link. Enjoy!
Related
I am currently working with an embedded FOX G20 V board with an ATMEL AT91SAM9G20 processor. I am hoping to be able to establish a connection by ethernet between this board, and a linux machine. The protocol of communication is using the uIP library (smaller implementation of TCP/IP intended for embedded boards).
Anyway, I've downloaded the developpment kit offered by the processor, and it has countless examples of different types of communications, one of which includes a hello world program.
However, at this point, even with the example, I'm relitvely stuck. I am un sure which file of the hello world project it is I have to compile since there are many of them. Is it the main.c that is located in at91sam9g20-ek.zip\at91sam9g20-ek\packages\basic-emac-uip-helloworld-project-at91sam9g20-ek-iar.zip\basic-emac-uip-helloworld-project-at91sam9g20-ek\at91sam9g20-ek\basic-emac-uip-helloworld-project\ or is it another file?
The whole point is to get a communication established by the board and the remote host (in this case my Linux machine), and send it "hello world" through ethernet. I am guessing that the application in this case defines its register addresses in which the board will be able to receive the connection from the remote host (I may be wrong).
In any case, I am hoping to get help by any "experts" that are familier with the project that may guide me, or explain to me how exactly to build this application they have provided.
I'm not familiar with this board but according to this link the application is supposed to start a telnet server (on port 1000) and an http server. I suggest that you look at the output on the serial link (to get the IP of your board, let's assume 10.159.245.156 as in the example), and if you get what is expected then you can try to telnet to your board:
telnet 10.159.245.156 1000
The kit gives you project file for three toolchains (IAR 5.4, Keil and GNU). You'll have either to open the correct one depending on your toolchain (which one do you use?), or adapt if you use another one.
Edit: You apparently use the IAR toolchain, thus you need to open the *.eww file (for instance basic-emac-uip-helloworld-project.eww). This example only obtains an IP and displays statistics on the debug output (serial link?). There are other examples for a telnet or http server.
Moreover it's a detail but I think the emacs tag is irrelevant in your post. I think you confused EMAC (what is this?) and Emacs which is a popular text editor.
Okay I am going to try and be as discriptive as possible here to get this problem solved. I work at a company that makes BIG gear boxes and we have computers that run our Mills/Laths. These computers are currently FIT-PCs running XP. These computers are used to control the laths/mills via a usb to serial converter (PL2303_Prolific usb to serial converter). When it is plugged into an xp machine it is recognized as a com port. SO these machines are very old and are fail left and right, I intend to replace them with a raspberry pi running xfreerdp but I can't seem to get the usb serial device to be redirected to the virtual machine it is remoting into. Has anyone ran into this/know a fix for it? Please ask me questions if you are unsure of something because I am completely stuck here. TLDR Using raspberry pis as thin clients need to push a usb 2 serial cable through to the virtual xp machine
Unfortunately there are known issues with USB on Raspberry Pi. They're aware of the issue and working on it, but it is as of yet unresolved.
The USB Redux thread was created to capture the state of the work as well as the current list of work-arounds. The USB/serial converters are broken is a related thread.
There is hope, however. First, they are working actively to fix it, so I suspect it's just a matter of time. Second, there are a few things you can try.
There's a config file in
/boot/cmdline.txt where you can try adding a few entries. One that appears quite effective is dwc_otg.speed=1 and dwc_otg.fiq_fix_enable=1 (but they didn't help me). See this page for some examples.
Update the kernel (search for rpi-update) to at least #348 (use uname -a to determine the kernel level)
Good luck.
Update (Mar 13 2013). There appears to be a fix for the majority of USB issues as of kernel #389. Use rpi-update to update.
I bought a usb otoscope from the internet and I want to create an application that uses it. When I plug it into the computer, it reads the device as a USB Camera, and I can use the very barebones software supplied to communicate with it. I'm very new to the idea of communicating with usb all together. I've tried to look at some sites like this: http://www.jespersaur.com/drupal/book/export/html/21, that tell me how to reverse engineer a device. I don't know if I'm going down the right path with this...
I've downloaded USB Snoopy and I can't seem to get it to sniff the packets correctly. I also have Crunchbang linux installed on a different computer but I don't know how to sniff it on that either (especially because the drivers are native to windows). All I want is some sort of API/Interfacing functions for me to call and use. How do I go about doing such a thing? I'm able to locate the device on the device manager in windows, and it tells me hardware ID's and such. I can supply any information if necessary. Thank you.
EDIT - Small description I found of the otoscope: http://microscopesimgv.blogspot.com/2012/08/oasis-ehev2-usbplus-20mp-handheld-usb.html
would this tool help you any?libusbx is a cross-platform user mode library that provides generic access to USB devices
CHEERS!
I have successfully talked to the computer from an Arduino via serial USB port and I had the idea that I could make a keyboard or mouse with the arduino. Say I wanted to translate the computer's mouse 1 pixel to the left. What message would I have to send over the serial line in order to achieve this?
Google is a wonderful thing. "use arduino as mouse" returns 1.7 million hits. The third hit on the list takes you to the Arduino Playground for an example using the new Leonardo board.
Note:
The Leonardo differs from all preceding boards in that the ATmega32u4 has built-in USB communication, eliminating the need for a secondary processor. This allows the Leonardo to appear to a connected computer as a mouse and keyboard, in addition to a virtual (CDC) serial / COM port.
Assuming you don't have that board, here is another site for some other specific boards and yet another that is log for a project including hardware and software for older boards.
Hope this helps (and is a better answer to the question).
You would have to reconfigure the USB interface chip to appear as a USB HID endpoint.
Does anyone ever develop some application to control the spi device on OMAP3? I can load the spi driver "mcspi", but I don't know how to use it.
As of at least PSP 3.00.00.04, the mcspi driver is integrated with the Linux spi stack.
Turn on
CONFIG_SPI and CONFIG_SPI_OMAP24XX
in your kernel.
Here's how to use spi devices, in general.
There is also the spidev driver, which presents a char device to userspace, but it's experimental.
Ok So first I need to apologize for my previous shoot from the hip answer.
I too have now started looking into trying to get the McSPI's working and it has been some what painful. TI does not have lot of documentation, and I still haven;t been successful in getting any of the McSPI's to actually work, yet. But I thought I would post a link to the beagle board google discussion on the subject, as it appears they have been successful at getting at least McSPI3 working on the OMAP3530.
http://groups.google.com/group/beagleboard/browse_thread/thread/15d9488c1ec314ef/5ca06c67ff438106?q=mcspi3#5ca06c67ff438106