Monday, 28 August 2017

Pebble Steel improvised charging cable.

Every trip stuff breaks or gets lost or gets left at home.  The first thing on this trip was the realisation that I'd brought the wrong cable for my Pebble steel.  Getting a replacement on the road will be pretty much impossible so I needed to get an interim fix.  A quick internet search revealed a bunch of lashups that didn't really inspire,  but did confirm the polarity -  0v in the middle &  5v at the bottom.  I'd originally thought of making little spring connectors glued onto a plastic back,  with 2 part epoxy putty holding it together and soldered to and old usb cable.  To be honest it sounded a bit fiddly and time consuming, but it was a starting point, which quite often reveals the best solution.  When I went to look for a cable to cut up,  the obvious choice was the 10 way multi charger that I carry in case something unusual needs charging. 

While trying to decide which connector to sacrifice (probably apple), I noticed that the sony/ericcon K750 connector had spring terminals, which coincidentally are the same pitch as the pebble pads

As it happens the polarity of the pins matched up well with the pebble, so all I had to do was snip off the locating lugs, and use a bit of tape to hold the connector against the pebble.

A second piece of tape over the top makes the connection a bit tighter.

Wednesday, 15 April 2015

On the road again

Time for our next trip, and the van is fully loaded up. It takes about 2 days, and we have far too much stuff, mainly food - due to lack of planning.

Wednesday, 25 March 2015

Mr Beams MB390 Modded

The MB390 wireless battery-powered LED ultra-bright weatherproof spotlight puts out 300 lumens of bright white light. This battery powered spotlight instantly turns on when motion is detected after dark and switches off again after about 20s. Essentially it's designed as an easy install security light.

I bought on impulse from Amazon on a lightening deal for £20, with an eye to using it as an external light on the van. Since it used 4 1.5v batteries, I thought that a 5V USB supply might be enough to power it - and it did, consuming about 400mA.
However I wanted it power up any time, not just at night, and the on time would be far to short for normal camping use. Once you remove the waterproof cover, there are 4 screws holding the top cover with the Fresnel lens. This is the main PCB

Removing the light dependent resistor - with the red top, disables the dusk sensor - allowing the unit to operate day or night.
Bending the two clips at the bottom will release the PCB to get access to the underside.

The IC at the bottom is identified as LP0001, which is commonly identified as a BISS0001
Micro Power PIR Motion Detector IC.
This is the application datasheet, showing the typical design
According to the data sheet the on time  Tx ≈24576 xR10 x C6;
On the Mr Beams PCB tracing the tracks from the IC, this equates to R9 & C10. Since R9 is 100k, this means that C10 is 10nF. So Tx = 24576 x 100k x 10n = 24.5s
To increase the time, piggy back another cap onto C10 (to the right of the IC) to to increase the capacitance.
I chose a 100nF cap - so Tx = 24576 x 100k x 110n = 270s, about 4.5mins.
The default action of the detector circuit is to retrigger when the PIR detects movement. So in normal use when sitting in front of the lamp, it should regularly reset the 4.5 minute on cycle, avoiding the need for manic arm swinging to turn the lamp on again.

The black and red power wires ware rerouted to the external USB  cable, via the top battery connector, just in case I ever want to use batteries again

Finally, I removed the mounting base, and reamed out a hole to fit a suction mount scavenged from an old mobile phone kit. This allows us to fit the lamp to the side of the van in the evenings. I usually leave it on all night, to act a security light if anyone passes by.

Monday, 23 March 2015

Dash Cam

Although I'm not overly paranoid about such things, but after watching a YouTube video last year, where a pedestrian throws himself onto the bonnet of a stationary car, it was in my mind to get a dash cam. Also it may be nice to capture some of the more exciting roads we sometimes end up on.
As usual there is a great resource online at
After reading up for a few hours I went for a Mobius Action Cam, because of its small size, since I'll probably keep it mounted all the time.

I did not want to mount it to the windscreen, both to keep it discreet and because it may have interfered with the thermal screen. So I hacked up an old table cloth clip, to fashion a clip to attach the camera to the head lining.

This is the original clip (Clas Ohlson)

After sawing the motif off, and trimming and bending the spring steel clip, this is what I ended up with

With a bit of sticky velcro

Mounted camera

The mini USB at the rear is connected to the van 5V supply, via a relay powered by the ignition 12V.
The camera is configured to start automatically when the power is connected, and stop 10s after the power is cut. The recording function created an new slip every 5 minutes, and will record over the first clip again when the card is full.

Friday, 20 February 2015

Solar Panel

Prices of solar panels have finally come down to reasonable prices. Also the "flexible" panels make fitting much easier as well as significantly lighter. Photonic Universe on eBay had an offer for 1/3 off 100W panel at £140 - which in retrospect seems genuine since they are £215 today.

I decided that, since I was unlikely to use the panel over the winter, that I should make it removable.
I also plan to fit a roofbox this year, and long term it may make more sense to mount the panel on the roofbox.
So rather than glue the panel directly to the roof I sourced some plastic "j" section so that the panel could slide in on out.
After much searching around I found this from

2.5mm kpanel edge strip

You can get it in 2 or 3 metre lengths for £3 or £4, and shipping is only £3.50

Initially I tried using Tiger Seal to stick the rail down - which worked really well with the Aluminum awning rail. But after 3 attempts I came to the conclusion that this material wasn't in the "works with most plastics" category. Some Evo "sticks like s**t" did the job.

To stop any would be thieves I used a couple of  domed coach bolt screwed into the rear roofrack fixings.

To feed the wires through the roof, people typically use these

These ugly bits of plastic cost about £10.
The underside is open, so if you have a problem with the sealant you will get water ingress - and no way of knowing you have problem.
The other problem I found was that the cable glands were too big for solar panel cables - probably because they are usually used to TV/Satellite cables

A much neater solution was to use a solar panel junction box

These don't seem to be available in the UK, though they are easy enough to get on eBay from Hong Kong - or maybe Germany.
It very easy to open the box to check if water is getting in.
So I removed the internal connectors, and just fed the wires though holes (with grommets) in the roof, and stuck the box down with Tiger Seal

Here's the finished article.

The cables are terminated with MC4 connectors which plug into the solar panel connectors.

There are loads of solar controllers on eBay, many claiming to support MPPT, which is basically a method of supplying the battery with maximum available current at the optimum voltage, regardless of  whatever voltage is coming from the panel. Unfortunately many of eBay models are fake, using the standard PWM type charging, which is less efficient, or even worse, just a bunch of bits that look like its a controller. I eventually went for a  German designed Votronic MPP165 from an eBay seller from New Zealand for about £55. It arrived within a week and seems to be genuine, though I haven't got the time (or inclination) to do proper testing - unlike the dozens of people posting on YouTube. I sent a few questions to the manufacturers in Germany, and they were very helpful and quick to respond.

Thursday, 19 February 2015

Rain Shields

On the odd occasion we are stuck inside the van, due to its small size, the sliding door and windows are usually open. This is also very important if cooking, to allow steam out. The only problem with this is that the rain comes in. The sun shade will stop this, but I know that it won't always be put up, unless we are staying put for a while. Again something quick & simple was required.
With the left over material from the sun shade, two smaller shades were run up, with awning piping sewn on one edge, and open seams for fiberglass poles on the other 3 sides.

To support the fiberglass poles I used Tiger seal to attach a length of U channel aluminium to the roof. The channel needed a slight bend at each end to fit the curve of the roof. Then I glued in some round aluminium into the channel - which was left straight so that the poles can be inserted easily.
The aluminium can be bought at Wickes - I had to bring the poles along to make sure they fitted since sizes can vary quite a bit.

Poles inserted, with awning piping inserted into C channel

 Rain shield outside cooker window

Rain shield over sliding door

 In theory, if rain collects, the weight will cause the shield to drop, and the excess will drip off. Though if it's raining that heavily the door will be shut anyway.

Wednesday, 18 February 2015

Sun Shade

On last years trip, we made a very simple sun shade, using a Eurohike tarp. It did the job very well, until it rained. Water would collect in the middle of the tarp, and the weight would pull the pegs out slightly, allowing more water to gather. Eventually the light polyester material stretched in the middle, making the problem even worse.

There are plenty of awning and sunshades designed for caravans and motorhomes, but I simply could not find any that would suit a micro camper. The closest was the Fiamma Caravanstor 190cm, but I felt that this was too bulky (and pricey at £200+). NR Awnings do make one that would have been perfect, for £79, however the length at 2.4m was just too long, and they were unwilling to modify. I did like the design however and decided to make our own.

 I wanted the material to have a high tensile strength so that it could be tensioned, to avoid pockets that rain could collect in, but not too heavy, so that it's easy to roll and store.
Dutch manufactured acrylic coated polyester, TenCate all-season WR-18 fitted the bill, with 100/140daN tensile strength and 2daN tearing strength, and at 240g/m3 it's reasonably light weight.
The quoted water column is >850mm, which compares very well to commercial awnings.
I ordered 204cm X 2.7m, and 125m of waterproof thread, from in the Netherlands, for around €55.

For attaching the main sun shade to the van I used the standard 6mm awning piping, which was sewn on. This is pretty easy to source on eBay.

To fix the shade to van I wanted an aluminum J rail, rather than plastic, for maximum strength.

I eventually sourced a rail used for Fiamma F35 awnings.
The problem with this though, is that it comes in 3m sections, which makes it costly to ship. In fact most suppliers won't even ship it without buying the full awning.
Fortunately Riversway sell them (search for  "Fiamma Adapter Rail") for £15.95 plus £6.95 shipping.

To fix the rail to the roof I used Tiger Seal, which once set has a little bit of flex, so hopefully I wont have problems with expansion stresses.

 Notches needed to be cut out to allow clearance for the roof rack mounting points

As and alternative to punching eyelets, which would require reinforcing the surrounding area I'm trying Holdon Midi clips. These push on and claim to be able to hold 75kg, and can be got for about £1.50 each.

Here is the final result. approx 2m x 2m.