Featured Posts

Broken Car Chargers – Part 2

Posted by admin | Posted in Technology | Posted on 14-06-2022

1

Well the St Helens rapid chargers were still offline after a month, so a moan on twitter to Osprey Charging quickly got a response that they were

“waiting on the OK from their insurers before repairing the chargers”.

That understandably didn’t go down well with several users;

Osprey then DELETED their initial tweet reply, and followed up with the more reasonable:

Well ok, vandalism obviously isn’t their fault – but an essential service offline for a whole month – when did you last see a petrol pump offline for a day or a week?

Update: two weeks later, the chargers were finally repaired – and instantly busy !

All’s well in the end !

Broken Electric Car Chargers

Posted by admin | Posted in Technology | Posted on 11-05-2022

0

So these chargers were vandalised at the Range, St Helens – screens smashed 😞😡

That was 5 days ago, leaving both out of action ever since, so now no rapid charging in St Helens (centre – others are 3 miles away)

Hope they get fixed soon, but makes me wonder how ready we are for EV uptake when an essential service like this goes offline, and takes a long time to be fixed – I’m reminded of burtonwood rapids being offline for over a year!

Even while I was here for just 5 minutes, two other EVs drove up, and left disappointed…

Update: They were offline a while – see https://redrobe.com/mike/?p=679

Recording TV on Raspberry Pi

Posted by Mike Redrobe | Posted in Technology | Posted on 13-11-2016

4

RpiAs an update to my previous guide, things have become a little simpler in Raspbian Jessie, since there is now a precompiled version of tvheadend available.

Add the TVHeadend repository to the pi’s sources list:

nano /etc/apt/sources.list

add the following line:

deb http://apt.tvheadend.org/unstable/ jessie main

Now we can install tvheadend:

sudo apt-get update && sudo apt-get install tvheadend

The rest of the configuration can now be done through your PC web browser, pointed at port 9981 of the raspberry pi’s ip address:

http://192.168.1.35:9981

Select your tuners from Configuration / DVB Inputs/ TV adapters, and click the enable checkbox for each one:

choose-tuners

Now goto the Networks Tab and click Add to create a new network

choose-dvb
(DVB-T for freeview)

Tvheadend has a list of transmitter to speed up the scan process, you can find your local transmitter by typing your postcode into http://www.ukfree.tv/transmitters.php

choose-transmitter

Give it a name (e.g. “freeview”), and click create.

Click the Muxes tab, and after a while, you should see channels (“services”) detected in the right hand column below:

muxes-display

Now it has scanned the channels, you can add them into the lineup, click on services, and then “Map-all”:

map-channels

I had to click play on one of the channels before the EPG would populate, but that may have just been a matter of waiting:

epg

Now you can browse the EPG, and record shows.

An hour long TV show takes around 1GB of space, so SD card storage would fill up quite quickly if left like that, I use an attached 2TB USB HDD, just change the location in Configuration / Recording / Digital Video Recorder / Recording System Path:
/media/usb/TV

Raspi Imager – Android app to download and install Raspberry Pi SD cards

Posted by Mike Redrobe | Posted in raspberry pi, Technology | Posted on 04-05-2016

9

Raspi Imager – Android app to download and install Raspberry Pi SD cards

New android app to download & image raspberry pi SD cards

Prepare bootable SD cards for your Raspberry Pi direct on your phone

– No PC required !
– downloads and installs OS
– images to SD card or USB (card reader)

Can install NOOBS and NOOBS Lite

Supports SD card in phone (if rooted- android limitations), or via USB card reader.

Android App

Phone and Card Reader

https://play.google.com/store/apps/details?id=com.redrobe.raspicardimager&hl=en_GB

Cluster of Raspberry Pi Zeroes

Posted by Mike Redrobe | Posted in Technology | Posted on 06-01-2016

4

No ethernet required – each pi zero is both powered and networked by a single usb lead !

PiCluster

The magic happens in the “gadget mode” firmware of the PI Zero. Since it doesn’t have the USB HUB chip in the way like other models (B / B+/pi2) it can be configured in device mode.

This makes it appear to any PC (or pi B+ / pi-2) as a virtual usb network adaptor – so you can immediately access it as though it were ethernet connected.
It also possible to set it up to appear as mass storage device, keyboard, mouse or any other usb peripheral!
(More discussion on the pi forums by DaveB and others)

Power isn’t a problem as each Pi Zero only uses around 150mA

    Convert a Pi Zero to gadget mode:

1. Start with an fresh image of Raspbian Jessie https://www.raspberrypi.org/downloads/raspbian/

2. copy this file to the boot partition: https://dl.dropboxusercontent.com/u/1122948/temp/PiOTG-Test/PiZeroEthernet.tar.gz (thanks to gbaman1 / Andrew Mulholland)

or download it on the pi itself:

wget https://dl.dropboxusercontent.com/u/1122948/temp/PiOTG-Test/PiZeroEthernet.tar.gz

2. sudo tar xvzfC /boot/PiZeroEthernet.tar.gz /tmp/

3. sudo cp -R /tmp/PiZeroEthernet/fat32/* /boot/

4. sudo cp -R /tmp/PiZeroEthernet/ext4/lib/* /lib/

5. Now give it a static ip address by editing /boot/cmdline.txt and adding this on the end: ip=169.254.64.64:::255.255.0.0

(for the lazy all the above has been done on this downloadable image:
http://sourceforge.net/projects/pizero-usbhost/ [768MB])

Now the pi Zero can be plugged into a pi2 / B+ (or a PC !) and you can SSH directly to it on the ip you set above ( 169.254.64.64)

[more to follow]

PiZero works with chromecast ethernet PSU

Posted by Mike Redrobe | Posted in Technology | Posted on 04-01-2016

0

Google sell a combined PSU and ethernet adaptor for the chromecast which works over a single micro usb….

Chromecast ethernet PSU

https://store.google.com/product/ethernet_adapter_for_chromecast [£15]

The PSU contains a USB-ethernet adaptor so it can provide both power and ethernet networking to the Pi Zero,which can be powered from the data usb port as seen above.

Power and networking with a single cable !

Fortunately the Pi Zero supports this chipset out of the box with Raspbian OS:

pi@pizero3:~ $ lsusb
Bus 001 Device 002: ID 0bda:8152 Realtek Semiconductor Corp.
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
pi@pizero3:~ $ lsusb -t
/: Bus 01.Port 1: Dev 1, Class=root_hub, Driver=dwc_otg/1p, 480M
|__ Port 1: Dev 2, If 0, Class=Vendor Specific Class, Driver=r8152, 480M

Speed ? Pretty good too:

pi@pizero3:~ $ iperf -c 192.168.0.62
------------------------------------------------------------
Client connecting to 192.168.0.62, TCP port 5001
TCP window size: 43.8 KByte (default)
------------------------------------------------------------
[ 3] local 192.168.0.60 port 48478 connected with 192.168.0.62 port 5001
[ ID] Interval Transfer Bandwidth
[ 3] 0.0-10.0 sec 112 MBytes 94.2 Mbits/sec

Chromecast ethernet adaptor is £15 on google play:
https://store.google.com/product/ethernet_adapter_for_chromecast [£15]

Raspberry Pi 2 – XENON DEATH FLASH

Posted by Mike Redrobe | Posted in Technology | Posted on 08-02-2015

1

Having just received a new Pi-2 , the updated version of Pi that’s quad core and 6x faster

I Was reading ths thread over on the official Pi forum:
http://www.raspberrypi.org/forums/viewtopic.php?f=28&t=99042
where PeterO found taking a flash photo near the Pi caused it to crash.

With a bit of experimentation:

Took photo with Samsung Note2 – Pi 2 remains ok
Took photo with Samsung K Zoom – Pi 2 crashes.

Note the K Zoom has a Xenon flash, unlike most cameraphone’s LED flash.

Other models of Pi – A/B/A+/B+ are all immune from the “XENON DEATH FLASH”

I thought it might be the SoC (Pi’s main processor chip) but a huge blob of blu-tack over that wasn’t enough to save it crashing

but turning the Pi upside down, did protect it – so we knew it was optical, not EMP

A raspberry Pi engineer, JDB, then isolated it to U16, the power supply regulator and sure enough a small blob of blue tack on that chip fixed the issue:

Here’s a better view of the problem chip:

Record TV on Raspberry Pi with tvheadend

Posted by Mike Redrobe | Posted in Technology | Posted on 07-06-2014

1

RpiI’ve had PC running Windows Media Center for a couple of years recording TV, but decided to replace it with – you guessed it – a Raspberry Pi!

The MCE box was using a couple of these gold Kworld USB dual tuners (UB499-T2):
kworld-ub499--t2

On connecting one to the Pi, initially nothing showed up in /dev/dvb, so I had to download the firmware to get it working:

wget https://github.com/OpenELEC/dvb-firmware/raw/master/firmware/dvb-usb-it9135-01.fw

Next, fetch some required tools:

sudo apt-get update
sudo apt-get install unzip libcurl4-openssl-dev pkg-config git build-essential dvb-apps

Download and compile tvheadend:

git clone https://github.com/tvheadend/tvheadend
cd tvheadend
./configure
make
sudo make install

(the above takes about 5-10 mins on a Pi model B)

Start tvheadend server with a blank password:

tvheadend -C

The rest of the configuration can now be done through your web browser, pointed at port 9981 of the raspberry pi’s ip address:

http://192.168.1.35:9981

Select your tuners from Configuration / DVB Inputs/ TV adapters, and click the enable checkbox for each one:

choose-tuners

Now goto the Networks Tab and click Add to create a new network

choose-dvb
(DVB-T for freeview)

Tvheadend has a list of transmitter to speed up the scan process, you can find your local transmitter by typing your postcode into http://www.ukfree.tv/transmitters.php

choose-transmitter

Give it a name (e.g. “freeview”), and click create.

Click the Muxes tab, and after a while, you should see channels (“services”) detected in the right hand column below:

muxes-display

Now it has scanned the channels, you can add them into the lineup, click on services, and then “Map-all”:

map-channels

I had to click play on one of the channels before the EPG would populate, but that may have just been a matter of waiting:

epg

Now you can browse the EPG, and record shows.

An hour long TV show takes around 1GB of space, so SD card storage would fill up quite quickly if left like that, I use an attached 2TB USB HDD, just change the location in Configuration / Recording / Digital Video Recorder / Recording System Path:
/media/usb/TV

To start tvheadend on bootup, add the following to /etc/rc.local before the exit 0 line:
/user/local/bin/tvheadend -f -u pi -g pi

Raspberry Pi Sales Timeline

Posted by Mike Redrobe | Posted in Technology | Posted on 29-04-2014

2

The Raspberry Pi has been a great success, with over 2.5million sold so far,
but there’s less information around on how many of each revision are out there,
particularly the percentage with “mounting holes” (rev2 onwards) or the split of 256/512MB models

So after a bit of trawling through google and correlating article dates with quoted figures,
it’s possible to put together a timeline of Raspberry Pi sales, together with landmarks along the way:

Raspberry Pi Sales Timeline

Now looking at that graph and data, we can glean some more useful information from it:

There are around 500,000 256MB Pi model B’s
There are approx 100,000 of the “rare” 256MB rev2 Pi.

15% are Rev1 models (no mounting holes)
20% of Pi are 256MB models (a fair bit more including model A)

Raspberry Pi Models

How many model A Pi’s are out there ? (model A’s are all 256MB)
No official mention at all, but no doubt liz/eben will say when a milestone is met ( 1/2 million, 1 million ?)

[Original spreadsheet with all data and links can be seen here:
https://docs.google.com/spreadsheets/d/1zWwpcckDEEVAhNH3y7JQGxxbjP42nUywPOzDWr1fH28]

Biped robot kicks a ball .. and has a great fall

Posted by Mike Redrobe | Posted in robots, Technology | Posted on 17-08-2013

Tags:

1

Kicking a ball:

Kicking  a ball

The kicking action runs the knee/hip servos at full speed, instead of slow smoothly interpolated sweeps like used in walking/ leaning

E.g.
CODE: SELECT ALL
Servo.hip = 90
Servo.hip= 140

vs

CODE: SELECT ALL
For sweep in range (90, 140):
Servo.hip = sweep
time.sleep (0.1)

Here’s a quick vid of it falling over when the battery pack detached, causing it to lose balance:


Pi biped