Power & Source of Big Ideas

Well, thank you very much for that. For years I have been running root on the mini2440, because it was that by default. I now see I needed some practice changing to a root login :)

Have a look at the NanoPi page.
I tried to change the scaling_governor on my netbook and found that even with sudo I can not change it there either.

There is some special process required to modify files in /sys/devices/system/cpu/cpu0/cpufreq

Nobody know the process?
Your suggestion did not work. I thought why not try changing the permissions on one of these files in /sys/devices/system/cpu/cpu0/cpufreq and see what happens. Well, if I change scaling_governor from 444 (as found in the provided Debian image) to 666 then I can modify it, say from from "intera...
Milling a cutout for the CPU just might be a bad idea. Looking at the substrate (daughter board) I see 3 very small metallic dots. My guess is these are test pads for bed-of-nails testing. You would not to accidentally connect to these pads. I have very limited internet access, at the moment. When I...
I would guess most of the heat that you could get out of this part would effectively be extracted by contact with the metal (?) top cap on the CPU. Have you tried searching for any recommendations from Samsung for heatsinking this part? My solution was posted on their other forum. Just where did you...
sudo = root

I read that Debian sometimes uses su as a "special root", but that doesn't work either
I want to change the CPU operating frequency by doing: sudo echo 800000 > /sys/devices/system/cpu/cpu0/cpufreq/scaling_setspeed and I get a message : Permission denied I have not been able to find any comments regarding Debian Jessie and any special behaviour on /sys Can you provide any clue? Thanks
Well, I was just reading through the mini2451 manual and it was describing the serial setup. Specifically, "data flow control OFF".

Yikes, my minicom had hardware control ON. Something changed when I wasn't looking.

Everything is OK now.
Annoyed by the fact that LXTerminal opens larger than the S701 screen? Right click on the icon and using gedit scroll down to the bottom of the file and change Exec=lxterminal to Exec=lxterminal --geometry=50x20 I noticed that only this application opens in the minimised position so maybe there is a...
Is doing a sync after modifying the file one of the well-known tricks :) Some distros mount etc as volatile so people couldn't change stuff in /etc. I don't think is the case with the NanoPi2. I notice that nameserver is modified by the operating system. Hopefully hostname is NOT hidden away somewhe...
Looks like it might be more difficult then I expected:


Also, it is not one of your recommended microSD cards, the recommended ones are on their way.
Doing: resize2fs /dev/sdb2 says it has done an on-line resize but then throws the error: davef@davef-AOD255E:~$ sudo resize2fs /dev/sdb2 resize2fs 1.42.9 (4-Feb-2014) Filesystem at /dev/sdb2 is mounted on /media/davef/rootfs; on-line resizing required old_desc_blocks = 1, new_desc_blocks = 1 Perform...
Good start. Now the error after: sudo resize2fs - /dev/sdb2 is: Filesystem at /dev/sdb2 is mounted on /media/davef/rootfs; on-line resizing required old_desc_blocks = 1, new_desc_blocks =1 resize2fs: Invalid argument While checking for on-line resizing support What type filesystem is on sdb2?
Could you explain how one can also "talk" to the NanoPi2 via the serial terminal?
So, fastboot for the 512 byte header file than just use other file copy methods for the kernel and rootfs.


Thank you.
After doing (in my case): sudo umount /dev/sdb (result) umount: /dev/sdb: not mounted sudo parted /dev/sdb unit % resizepart 2 100 unit MB print Warning: Partition /dev/sdb2 is being used. Are you sure you want to continue? parted: invalid token: 100 Yes/No? Does one ignore both warnings?
I can observe the bootup messages but can not control the NanoPi2 from the PC serial terminal.

Just a guess ... should there be a ttySAC0 in /dev?

Warning: you cannot update this MicroSD card by commanding "dd". This command which will cause trouble when booting the NanoPi2.

Could you explain why this warning applies to the NanoPi2?

I had already tried removing those lines in fusing.sh, but then that script asks you to download the debian image. As I had already downloaded the image I wanted (as suggested earlier in the Wiki document) I would not expect to have to download it again. I am currently in a remote location with limi...
Added LINUX pmount on the host: apt-get install pmount and in /etc/pmount.allow added: /dev/sdb no luck, then added /dev/sdb1 /dev/sdb2 /dev/sdb3 /dev/sdb4 still no luck. Am I correct in assuming that a 32-bit Linux host is adequate for everything except compiling your own programs using arm-cortexa...
I tried to flash a microSD card with the Debian image and get the following error: Error: /dev/sdb is non-removable device. Stop. After looking through fusing.sh I had a look at the contents of the file: /sys/block/sdb/removeable and find the character 0 I checked all my SD cards and they all say re...
Your measurement indicates a precise value (1.059V) I wonder how accurate it is? Which DVM are you using? Might be a good idea to measure the other voltages ... if they are closer to the stated values then maybe you can trust this reading. There are four more supplies using the same device. Your rea...
FAtechsupport, Just out interest which type of errors seem to be caused by a low VDD_ARM_AP? (As seen from his log.txt file) 1) hw-breakpoint: Debug register access (0xee113e95) caused undefined instruction on CPU 1 2) Fail, noack i2c.2 addr [0x70] data[0x70], trans[ 0: 1] 3) Unable to handle kernel...
On page 43-2 you will find 1.14V min 1.2 V 1.365V max. Also the MP2143DJ has a tolerance of +/-1.5% within the voltage range of 2.5V to 5.5V PLUS a temperature variation of +/-2% over -40 to +85C (quite impressive). So, there could be about +/-2.5% over typical operating conditions. The 120K you sug...
Alternative to increasing R452 is to decrease the value of R453. However, the most helpful piece of information would be ... what is the acceptable voltage limits on VDD_ARM_AP. Then measure that voltage before deciding to make any changes. You will need a fairly good-quality DVM. If you decide to c...
Thank you.

But does it adjust the CPU frequency dependent on temperature?
Is it enabled in the kernel for the NanoPi2? I downloaded cpufrequtils on my NanoPi (not the NanoPi2) and was given the message: root@nanopi:/# cpufreq-info cpufrequtils 008: cpufreq-info (C) Dominik Brodowski 2004-2009 Report errors and bugs to cpufreq@vger.kernel.org, please. analyzing CPU 0: no o...
Is your system really slow reading the packages list? A procedure is explained at http://antti-juhani.kaijanaho.fi/newblog/archives/521 I just did this on my NanoPi, so should apply to the NanPI2 as well: dpkg --clear-avail (Evidently, dpkg --forget-old-unavail is not required) Downloaded the dctrl...
Is your system really slow reading the packages list? A procedure is explained at http://antti-juhani.kaijanaho.fi/newblog/archives/521 I just did: dpkg --clear-avail (Evidently, dpkg --forget-old-unavail is not required) Downloaded the dctrl-tools package and ran sync-available What a difference!
Bootargs and what happens if you make a mistake Connect TFT LCD (section) on the NanoPi Wiki page fw_printenv bootargs Append "lcd=S70" to "bootargs=" and reset the list with "fw_setenv" Suggest that line is changed to: Append "lcd=S70" as shown below and sav...
Well, according to http://ubuntuforums.org/showthread.php?t=2162439 this is expected ifconfig behaviour. Solution is : ifconfig wlan0 down ifconfig wlan0 up I found that the down command was enough to update the ifconfig wlan0 entry and to bring wlan0 up again, but perhaps there is a good reason for...
Tried another few things:

ip addr flush wlan0

that get rids of the wlan0 entry in ifconfig, however on reboot it reverts to my old inaccessible router.

dhclient -v

says that the NanoPi is bound to my local router.

Where does ifconfig get it's information from for the wlan0 entry?
OK, don't bother trying to log into a 2nd WiFi AP. Even though the router I am currently trying to access says WPA2-PSK it also says that it needs CCMP+TKIP. TKIP is a cipher for WPA. When I changed: wpa-pairwise & wpa-group to CCMP TKIP it now works. Now, for the bizarre part ... ifconfig says ...
Trying to connect to another WiFi AP after successfully connecting to the first WiFi AP is still causing me problems. Most of the examples I find for connecting to multiple WiFi APs use a /etc/wpa_supplicant/wpa_supplicant.conf file rather than the /etc/network/interfaces.d/wlan0 file in the NanoPi ...
Invoking the command:

find -name xyz -print

does not appear to work the first time, so just repeat the command
Try the following as it might supply more information:

Go to /var/log and
rm daemon.log
touch daemon.log (just in case a new one is not automatically generated)


Go back to /var/log and
nano daemon.log

I think you will see some responses from the router which might help.
2) I had to download iwconfig after I was able to connect to the internet.

iwconfig is more informative
Wanted to disable Bluetooth so found this modification:

in /etc/rc.local

add this line:

rfkill block bluetooth

before the line:

exit 0
After a few hours trying to understand a variety of errors I did the following: apt-get upgrade apt-get dist-upgrade apt get autoremove and then downloading packages behaved as expected. Perhaps the above is "standard-procedure" after installing a new Linux OS, but maybe worth mentioning a...
Well, after successfully accessing another two Smartphones and another wireless router, I tried my TP-LINK again and now it works. Following an example on Ubuntu help pages, I put: wpa_proto WPA RSN see https://help.ubuntu.com/community/NetworkConfigurationCommandLine/Automatic and the section WPA s...
Looking at the first error message: [10347.440300] dhd_preinit_ioctls buf_key_b4_m4 set failed -23 and in dhd_linux.c at line 3979 one will find the text in the error message: "buf_key_b4_m4 set failed" There is no comment before: bcm_mkiovar("buf_key_b4_m4", (char *)&buf_key...
Signal strength is not the problem.

wpa_cli -iwlan0 scan_result shows -37 (dBm) as the NanoPi is about 1 meter away from the Wireless router. Also, I had tried WPA2 with no result.

I will try again in a few days.
Seems a number of us are having the same problem trying to access certain APs. Refer to this thread for details:

Appreciate your comments.

Under Hardware Features:

microUSB x1: for power and data transmission. It can be configured as a serial port or Ethernet

Where is this feature configureable?