Wednesday, 18 October 2017

File resolv.conf changed on reboot

The file /etc/resolv.conf was being reset and losing the correct nameserver on my Raspberry Pi after a reboot. The unfriendly way of fixing this was to make the file immutable using :-
sudo chattr -i /etc/resolv.conf 
It worked but I know this isn't the correct way to do it , but hey-ho life's too short....

Tuesday, 26 September 2017

Broken Ubuntu Mate Desktop

I had Ubuntu 16.04 LTS installed as a guest on a Windows 10 OS. The VM was shutdown uncleanly and after that its Mate Desktop wouldn't run properly. I re-installed the MATE Desktop using the following command.
apt-get install ubuntu-mate-desktop --reinstall 
After the re-install it worked fine with no problems. I'll remember to shutdown the VM properly next time.

Friday, 4 August 2017

Virtualbox USB Problems

Using a PC running Ubuntu with Virtualbox using Windows 10 as the guest I found I could not add usb devices using the add new usb filter. After a bit of searching I found information about the issue here.
I had to run the following command to get it to work , remember to log out and log back in after running the command.
sudo adduser $USER vboxusers
After that the add USB devices filter worked fine.

Friday, 30 June 2017

iAQ-CORE_C I²C Problems

Problems with the iAQ-CORE-C Indoor Air Quality Sensor Module. I built the module onto a breadboard pcb and while testing I found that it would not work. I couldn't detect the device on the I²C bus of the Raspberry Pi I was using. Although I could use other devices on the bus without a problem , I found a lot of forums with entries about clock stretching causing problems for the Broadcom SoC I²C bus. I even tested it on an Arduino and no data from the device was detected. After a long time checking and testing the breadboard I came across an error in my wiring that turned out to be the problem. The wire for the SDA Pin 4 was connected to NC Pin 1 on its way off the board to the Raspberry Pi. There is no mention in the manufacturers data sheet not to connect to this pin it even says not connected. I spent a fair amount of time debugging this fault and eventually got it working

Wednesday, 15 March 2017

BT Infinity in a Closer Cabinet

I have BT infinity but this gives about 15Mbps download 1Mbps upload , not very good really. The reason is I am about 1.5km from the Cabinet providing my FTTC so the attenuation in the copper and increased noise pickup causes the drop in speed. I however noticed some contractor white spray paint symbols on the pavement about 200 metres from my house with the letters A.I.O and a box shape , see my photo below.I think the AIO stands for an All In One Cabinet that BT sometimes install in outlying areas serving a smaller number of subscribers than is typical.
The main BT cable bundle that serves my house is in the duct marked BT in the picture below , so I am wondering/hoping that I will get moved from the far away one to this A.I.O cabinet? This would mean I could get true infinity speeds so I'll just have to cross my fingers and hope that this will happen.

Wednesday, 25 January 2017

Getting ESPlorer to Run on Mint 17.4

I was having problems getting ESPlorer to run on my Linux machine , this to program an ESP8266 Wemos D1 Mini Clone with Lua , html content and an HA Bridge running on a Raspberry Pi for use with an Amazon Echo to control some RF remote control mains sockets. The error displayed from the console was  :-
# A fatal error has been detected by the Java Runtime Environment:
#
#  SIGSEGV (0xb) at pc=0x00007fe595a40009, pid=11774, tid=11803
#
# JRE version: OpenJDK Runtime Environment (9.0) (build 9-internal+0-2016-04-14-195246.buildd.src)
# Java VM: OpenJDK 64-Bit Server VM (9-internal+0-2016-04-14-195246.buildd.src, mixed mode, tiered, compressed oops, g1 gc, linux-amd64)
# Problematic frame:
# C  [libjava.so+0x1d009]  JNU_GetEnv+0x19
I used the command :-
sudo update-alternatives --config java  
and had the choice of either java-8-openjdk-amd64 or java-9-openjdk-amd64 on my machine. The default was java-9-openjdk-amd64 so I selected java-8-openjdk-amd64 and ESPlorer then worked without issue , I hope this helps someone in the same position.

Thursday, 18 August 2016

3D Printing PLA Not Sticking

I have found that using blue masking tape works for helping adhesion of PLA on heated build plate. Though the brand I bought was not very good in that the print wouldn't stick to the plate. 3M blue masking tape is apparently the best for this. While I waited for this tape to arrive I used hairspray sprayed onto the glass build plate , this provided good adhesion for my prints. I like the idea of the blue tape as it's less messy than the hairspray method. 

File resolv.conf changed on reboot

The file /etc/resolv.conf was being reset and losing the correct nameserver on my Raspberry Pi after a reboot. The unfriendly way of fixing ...