Raspberry Pi-Mote Mains Control

We are currently reviewing the Pi-Mote from Energenie. This is a small Raspberry Pi compatible radio transmitter board which can control up to four 13A mains sockets. We are reviewing the starter kit which includes two radio controlled sockets and the Raspberry Pi transmitter board (pictured below).

Raspberry Pi Pi-Mote Transmitter BoardThe Pi-Mote simply plugs onto the GPIO pins of the Raspberry Pi (compatible with both Raspberry Pi B and B+ but for the B it takes up all of the GPIO pins) and then a simple provided Python script is run on the Pi to supply an identifying control code to each of your sockets so you can subsequently toggle them on or off individually (or all at the same time) as and when you desire.

We sell a lot of low voltage controllers designed to be used to control mains powered devices – e.g. pumps in solar water heating pump controllers and in rainwater toilet flushing systems, immersion elements, motors, lighting, heaters, coolers, etc. The benefit of the Pi-Mote is that it is completely unnecessary to mess around with any mains wiring – you just plug the mains powered device(s) to be controlled into energenie radio-controlled sockets, and then use software on the Raspberry Pi to control the devices remotely.

Energenie raspberry pi controlled mains socket

We will be conducting a thorough review of the Pi-Mote and writing some Python scripts to provide some real world examples of its potential uses for a detailed article coming soon on the REUK.co.uk website. In the meantime, click here for more information or to buy the Pi-Mote Starter Kit now.

Valiant PremiAIR 4 Stove Fan

In our article Valiant Heat Powered Stove Fan published back in 2012 we reviewed the FIR300 Self-Powered Stove Fan from Valiant and showed how this device can help increase the temperature in the room being heated by a logburner or multifuel stove.

Comparison of Fir300 and Fir361 stove fans from ValiantThe reviewed FIR300 stove fan is pictured above on the left next to the new PremiAIR 4″ Stove Fan (FIR361) also from Valiant which we will soon be reviewing in detail.

The immediately obvious differences are the four blades instead of two which should increase the air flow, a new motor, and a more compact design with the motor housed within the heatsink rather than protruding out from it.

The heatsink on the new PremiAIR 4″ has a larger surface area with a new design for faster heat dissipation. Therefore more power should be available to the motor by the seebeck effect increasing the effectiveness of the stove fan.

Rear view of Fir361 PremiAIR 4 inch stove fan from ValiantWhen reviewing the FIR300 stove fan, we used an accurate digital thermometer and manually logged the temperature in the room minute by minute. For our FIR361 review we will put together a multi-sensor datalogger using a Raspberry Pi and/or Arduino to collect much more data for analysis so that the effectiveness of the fan can be judged – one sensor at sofa height, one at ceiling height, one close to the stove, etc.

UPDATE JAN 2014 – We have now published our detailed article: Valiant PremiAIR 4 Heat Powered Stove Fan Testing on the REUK website. In the end, rather than building another SD Card Datalogger for this project, we used a Raspberry Pi Model A+. We will be publishing a detailed article in the coming months on how we programmed and set up this datalogger (including the source code), and also how viewed the data in real time through a mobile phone browser.

Bricking a Beaglebone Black

In a previous article we introduced the Beaglebone Black – a low power, low cost, credit card sized Linux computer available in the UK for around £35 and just $45 in the USA. We have been using the Raspberry Pi since it was first released in early 2012, so we were very interested to try out this similarly priced alternative which promised greater processor speed, 2GB of on board eMMC flash memory for the operating system, and most importantly for the work we do, 7 analog (ADC) inputs compared to zero on Raspberry Pi.

Beaglebone Black - low cost Linux computer

We received our Beaglebone Black (pictured above) around a week ago, and have been playing around with it in any spare time. Getting it set up was very quick and easy following the instructions served up as a webpage from the BBB itself. But then today something went wrong.

While looking on the internet to find any recommendations/suggestions for a VNC (virtual networked computing) server for the BBB I found this recent blog posting by Roger Meike which went through the steps he took to successfully install the X11 VNC server on his Beaglebone Black. This enabled him to interact with its full graphical interface / desktop through his Mac instead of having to hook the BBB up to a separate monitor or TV or only being able to use the command-line interface terminal via SSH.

So, step one, connect the Beaglebone Black to the ethernet cable and USB cable – check everything is working as it should via SSH.  Step two, update and upgrade the Ångstrom Linux distribution installed on the Beaglebone. So far so good – seemingly. The command opkg update took very little time to run to completion; the command opkg upgrade took the best part of an hour and a half to run, but didn’t show any errors, and after it was completed everything was working as it had previously – no problems evidenced at all.

Before embarking on the X11 VNC server installation I decided to reboot the Beaglebone Black, so I entered the reboot command. Next time I looked at the BBB a few minutes later 3 of the 4 user indicator LEDs were fixed on instead of their usual flashing. I attempted to SSH in but could not connect, and entering via my web browser (which is the usual way of accessing the BBB when it is connected to your computer via USB) resulted in ‘This webpage is not available’ error message.

Unresponsive Beaglebone Black after update and upgrade

It appeared that something had gone wrong somewhere, but the start up guide mentioned that the LEDs are fixed on while the eMMC is being flashed with a new distribution from the SD card and that process can take up to 45 minutes. On the off chance that upgrading the distribution without the SD card results in the same thing (and not wanting to turn it off if it was actually doing something), I left the BBB alone for a couple of hours, but the LEDs just stayed on.

I next pressed the on board reset button. The LEDs turned off, then one turned on (PWR LED), then another turned on (labelled D2), and then a few seconds later LEDs D3 and D4 turned on and stayed on permanently.

Beaglebone black user LEDs

Next I unplugged the USB cable and left the Beaglebone Black disconnected from the power that cable supplies for a few minutes. When I reconnected the USB cable to the computer, nothing happened – the computer could not see the BBB whereas it previously recognised it immediately as a USB mass storage device when it was connected. But the LEDs still came on.

I tested there was nothing wrong with the USB port on the computer – it was fine; I tried connecting the BBB to alternative USB ports on the computer, and still nothing, just the LEDs permanently fixed on.

I then hooked the BBB to a monitor via HDMI, but still nothing. It seems that it has turned into an illuminated brick.

Looking around on the internet I found this guide to unbricking Beaglebone Black without Erasing eMMC, as well as comments from other people who have run into similar problems with their BBB. It seems the only way to fix this is to download the latest Ångstrom distribution on another computer, unzip it, get an image writer for Windows, write the image to the SD card, boot from the SD card, and then wait for the image to be copied across to the eMMC. But, this requires a microSD card which I don’t have, and a lot more time. Also, quite a few stories of people going through this process and ending up with an un-bootable BBB. Is it necessary to do this every time the distribution needs updating??

I’ve never had any problems with any Raspberry Pi, and I have some which have been running continuously for months without crashing or any other issues. Therefore this bricked Beaglebone Black is going to be returned – not to be exchanged for another Beaglebone, not for a refund, but for another Raspberry Pi. Sometimes the grass is not greener on the other side – I just wish that the Raspberry Pi GPIO included some analog inputs!

As Nigel D wrote regarding the advantage of Pi over BBB: having the boot stuff and OS on removable media means that bricking the board is that much more difficult, makes it easier to experiment between different operating systems, and makes full backup and recovery easier.