So I can flash the eMMC from the BBB. However I downloaded from wget https://rcn-ee.com/rootfs/2016-06-09/flasher/BBB-eMMC-flasher-ubuntu-16.04-console-armhf-2016-06-09-2gb.img.xz the Ubuntu image and extracted and placed it on the SD card through Win32DiskImager.
I put the SD card in the sd slot and tried to boot by pressing the S2 button while I connect the board to the usb for power to my laptop. I wait for LEDs to turn on and nothing happens. It works without the SD card, but not with it. Nothing blinks, nothing when I connect via ssh. Any ideas?
So my answer was quite simple. It's best to get the UART Debug connector, see here. That way you know when you power on the BBB, the output of U-boot is displayed on your terminal when you serial connect (putty). If it does not find the image, the U-boot will send messages to the terminal notifying you that there is no kernel image.
Getting the UART Debug connector and connecting through serial is different than ssh'ing to the actual BBB. The output of the BBB (when you ssh) just notifies when everything loads up and the login information to the BBB is displayed on terminal. If your board cannot find the kernel, nothing will output, and you won't know what is wrong. However, if you connect serially through UART debug you wont have to worry, since you get to see output and error messages from U-boot telling you what's wrong.
*NOTE*: If you screw around the U-boot, which you should NEVER do (unless it really needs an update), that is the only way I can see there being no output whatsoever from the terminal when you turn on BBB and have the UART debug connected. If you didn't screw up the U-boot, then more than likely its a faulty BBB and you should return it.
HOPE THIS ANSWER WILL HELP OTHERS!
Related
I'm looking to install Linux onto an Intel Galileo Gen 2 utilizing this and this via installing onto an SD card.
I believe I have successfully done this, as during the boot sequence I am able to select Linux to boot from, however as soon as it starts booting from Linux, I am unable to interact with the Galileo anymore by say typing in my username and password when it comes time to login.
I'm unsure if my peripheral setup is wrong, if I need to install some more drivers to support I/O or something else.
I am viewing the logs from the Galileo via an FTDI cable and currently have a keyboard plugged directly into the Galileo.
Log data
When I boot the Galileo, this is what is logged.
Interestingly, the
flashing cursor stops flashing and is just steady when I get to the
login screen, as if the device is sort of frozen
However if I then
say connect a keyboard, it recognizes it and outputs this log data.
Solved! Turns out it was a faulty FTDI cable!
My question is about Lichee Pi Zero board (based on Allwinner/Sunxi V3s SoC).
Initially I used pre-built Linux image (kernel 4.10.02), it has no built-in Wi-Fi support (for Realtek 8327BS chip), so I downloaded the latest kernel version from here and built it with the default settings.
LCD is ok, Wi-fi looks good too (LED is blinkikng), but I cannot use keyboard anymore - there is no reaction from OS, when I connect something to USB (no message and no input from keyboard).
Hardware is OK and works good with the old Linux image.
I have also tried the latest kernel from kernel.org with the same bad result.
Please help to understand the reason. I suppose bad settings, but HID supoort is enabled.
Update 1.
I establish connection through UART. As I see, some USB features are detected during boot:
I'm able to load some drivers using insmod also:
Unfortunately, Linux still does not recognize any USB Device. I have connected mouse, keyboard, hub, mass storage and got no reaction from OS. It looks like devices do not get power (there is no light from mouse).
Update 2.
The best way I have found at the moment is to use buildroot-licheepi-zero.
It's very easy to use:
make licheepi_zero_defconfig
make menuconfig (optional)
make
After many-hour wainting I got the sdcard.img. It includes all neccessary files (zImage, RootFS, u-boot.bin, etc) and could be placed to SD with linux dd or etcher.
Linux boots successfully, but you can use terminal only through UART, as there is no LCD output.
You can put LCD itself to work:
make uboot-menuconfig
make
BUT there is still no user login prompt on the LCD after boot. So I need to log in and put command through UART.
Please share suggestion if any.
Update 3.
The change below enables login prompt on LCD (and disables it through UART):
make menuconfig
Now we are able to use Wi-Fi:
insmod /lib/modules/4.14.14-licheepi-zero/kernel/drivers/staging/rtl8723bs/r8723bs.ko
ifconfig wlan0 up
edit file /etc/wpa_supplicant.conf to add your Wi-Fi SSID and PSK
wpa_supplicant -B -d -i wlan0 -c /etc/wpa_supplicant.conf
udhcpc -i wlan0
Connection is established now, we can ping and so on.
There is still the question - how to enable full-functional terminal both on LCD and UART.
Many thanks!
With regards,
Maksim
The best solution is to use Buildroot.
Please check updates at topic start for details.
I got a measuring instrument which can measure light intensity and this instrument can be connected to a PC via USB.
I now want to be able to read the values from the device via a Raspberry.
When the instrument is connected to the Pi, it shows up when entering 'lsusb' to the terminal and it is also listed under '/dev/usb' as hiddev1
But how can i actually grab the data from the device?
When i enter 'sudo cat /dev/usb/hiddev1' nothing happens.
Thanks in advance for your help
Try using HIDAPI, a cross-platform library for accessing Human Interface Devices.
I have tried communicating via serial (OSX w/ prolific drivers -> USB RS232 adapter -> Tx,Rx and GND pins on device serial ttl port) to a device and done so successfully using
screen /dev/tty.usbserial 115200 8N1
I get to log in and use it as if I was SSH or TelNetted in...
However whenever I try to go into system recovery mode (holding CTRL+1) while the device is powering on, it starts displaying weird characters and until I close the screen session it will continue showing weird characters:
Of course when we tried doing the same thing on my boss' macbook running windows and PuTTY and everything worked fine, even in system recovery mode; characters were displayed properly.
What gives? Id like to learn the intuition to use because up till now I concluded that since I can bot into the system and see characters normally everything about the connection should be fine and its must have been the recovery partition that was broken. This was wrong of course...
Niko
Dunno if it is a OSX problem,
I had similar problems before. I fixed it either by changing the Baud rate of the com ports or by making sure the Ground on the circuit is the same as the ground of the supply.
I have two legacy machines connected to a Linux box with USB using the ftdi_sio driver, to /dev/ttyUSB0 and /dev/ttyUSB1. The Linux box is relaying and analyzing the traffic between the machines. When the Linux box boots up, the machines are connected to the files pretty much randomly. The problem is to know which one is which.
I could just ask the devices, of course, but I'd like to avoid the risk of malfunction due to sending wrong data to the wrong device. Is there a way to figure out, for example, the id of the device connected to a tty file?
Check this Using Linux USB page.
/proc/bus/usb/devices lists information about the devices currently attached to the USB bus. This is very useful when trying to figure out if the device is correctly enumerated.
Maybe you can use the output from lsusb -v and look at iProduct + iSerial to determine the order the devices are attached.