Monday, 2 January 2017

Wideband Gauge

Nice sitting down/post Christmas relaxing sort of project - playing with some parts to build a Wideband Lambda gauge/real time readout on the lambda sensor.

Inspired by the work of Jonas Bylund:

I'm making some modifications so my gauge will be a bar-chart and fill from lean to rich - the same direction the emerald software does and because it will give a visual representation of fuelling - more lights = more fuel. The gauge takes the 0-5v feed from the Wideband sensor and is just a calibrated volt meter to show a central 2.5v of that range.

Knocked up the simple circuit based on 3x LM3914 which do all the work, requiring only few external trims, resistors and a pullup system on the LEDs to make the display work in reverse. 

Oldschool transfer to a veroboard layout using TinyCAD and VeeCAD - all free! Half the fun with vero is trying to get that optimal layout.

...mocked up part of the circuit to check operation.

This should give me a reasonably accurate 0.1AFR per LED across 30 LEDs - 12.6-15.5 AFR- either in the tested pre-formed units or an array which will let me hi-light specific values with different colours.

Sunday, 1 January 2017

Lands End 2016 - Summary & Video

The journey let me visit some of my favourite West Country locations as well as discover a few new ones, a target end point is the excuse I need to get out in the weather and just drive.

The ~700 miles round trip were worth it for this picture alone.


Will be uploading some video to the Youtube channel, don't expect any major editing - more a scrapbook/realtime TV to jolt my memory. Mostly wet roads so certainly not pushing the car and definitely concentrating on keeping the rear wheels where they should be - behind the driver.

I really must sort out the sound - my camera position most of the time has a better view than the driver, but does pick up more whining diff than burbling engine. Perhaps the SJCAM can be modded to accept an audio input?

Happy New Year!

Thursday, 22 December 2016

Going Home

The last leg - Sidmouth to home, not a direct route, via Lyme Regis, Dartmouth, New Forest.. but not really sight seeing any more, that going home mood takes over and its all about the end result now.

One pause outside Lyme Regis - this view along the coast and early morning sun was just stunning, the photo captures a little of the atmosphere.

The sky was clear and bright today, which also meant - cold, the coldest of the trip.
Fuel stops also now windscreen and headlight cleaning stops and once home mid-afternoon the once clean motor is showing the evidence of its approx. 700 mile journey.


  • I think the clutch cable needs adjustment - a couple of times its been a little tricky to get into 1st - possibly cable stretched a little?
  • The new USB power outlet, replacing the old 12v lighter sockets, also need some attention - its crashing the satnav on ignition off and not cleanly cutting power to the camera.
  • Camera is fine for picture, but picking up differential whine rather than nice engine noise - perhaps a mod is required for a remote mic.
  • Noticed at night, the shift light starts to glow, very dimly, about 1k revs under its set come on point. May indicate the Emerald sincs current on the shift pin progressively and perhaps an opportunity to build a sequential shift light based on that - i.e. line of comparators (LM3914) converting the linear current sinc to discrete LED indication.

Otherwise - everything ran fine, cannot beat that open to the sky feeling and a little of that pure escapism from a road trip.

Wednesday, 21 December 2016

Lands End, Mousehole, St Ives

This is the core of the trip - approx 164 miles, Lands End then the coast road to St Ives and back towards my home side of Dartmoor.


Wet overnight, but a clear start - cloudy but not too cold.

My first port of call is a mile down the road in Mousehole - narrow streets but luckily empty at this time in the morning and space to setup some photos on the quay.

I always fancied retiring to Mousehole, running the second hand bookshop and calling The Ship Inn my local. I would be a 'happy being grumpy' Black Books style shop owner. However its too early in the morning to check out the local establishments today.

Lands End

Then the drive to my end point - Lands End.

All closed up off season - two other cars in the carpark, one couple taking a dog for a walk and a group of 3 Chinese tourists. The situation does give me the opportunity for some good photos though.

A chat with the Hotel staff allows me to remove some bollards and get close to the cliffs. GN13 and me are now as far west as we can go in the UK before the roads run out. To the west are the Isles of Scilly and then the U.S.A.

...and the memento shot under the famous sign...

The Levant Mine

Onwards around the coast road towards St Ives, I randomly saw a sign to the infamous Levant Mine...

Officially closed - but had to be seen, so reversed up, carefully picked my way down the cobbled access road and went for a wander...

The miners followed the tin and copper for 2.5km under the sea in the 19th century, and lost ~30 men in one accident on the man engine in 1919. You have to admire the confidence of the engineering here - or perhaps the mix of engineering and business pushing the edge of what was possible/advisable?

Somewhere best part of a mile out and 700 metres down is the end of the mine, and less than a hundred years ago - men working in tunnels under the sea to retrieve metal ores.

St Ives

Getting towards lunchtime with St Ives around the corner. In the heatwave of 1976, in my childhood, we had a memorable family holiday here. Today its a little cooler - so after a wander around the streets and some Christmas shopping I holed up in a harbour facing chippy for lunch.

Fish, chips and mushy peas, pot of tea, ice cream for desert and a view over a slightly rainy, off season, UK seaside town - what could be better than that!  very happy!

After lunch its back towards home, across Dartmoor in the dark, past Exeter to overnight in Sidmouth. 

A Full day.

Tuesday, 20 December 2016

Dartmoor and Bodmin

This is going to be a day of cliches and favourite spots getting me close to the trip end point, another ~100 or so miles towards Penzance.

First thing I'm greeted with a wet drizzly morning - I also managed to dump a load of water from the tonneau into the drivers footwell - so spent some time bailing that out before starting. Hood up for this first bit.

The House of Marbles is my first stop - a chance to dry out, grab a hot chocolate and see some glass blowing. Sort of a habit to visit this place, wander through the marble museum and watch the weird contraptions ferrying snooker balls and marbles around metal mazes.

Then the north east to south west road right across Dartmoor.

Lights on most of the day through the low cloud, but running with hood off now, its not a particularly fast road - limited to 40mph, but good countryside - and really getting away from most man made things (apart from the road itself of course).

Pause for lunch virtually in the middle of the moor at the Two Bridges Hotel.
Each stop now, I wring out the rag in the drivers footwell and place it back to soak up more rainwater.

The Two Bridges is a friendly warm place - good food, open fires and friendly staff.
Bangers and Mash for lunch alongside a pint of Orange Juice and lemonade, gloves on the radiator to warm through before starting out again.

The weather a little clearer with good views as I pass the prison with its unmissable brutal architecture then off the moor and towards Bodmin to catch up with some old friends for a cup of tea and a chat.

The overnight stop at The Kings Arms in Paul, near Mousehole (another favourite Cornish place for me) and striking distance of my ultimate destination for the next day.

Monday, 19 December 2016

A303 West to Buckfastleigh

Just a road, except the A303 is the route to the west country.

As you get closer to Dartmoor, the road starts to roll over the hills - like a roller coaster - single carriageway, then dual & plenty to see along the way.

224 miles planned to take me to Buckfastleigh and the eastern side of Dartmoor.

Just as things snarl up behind a tractor Stone Henge comes into view on the right - seems much closer in real life than the camera picks up.

This speed camera might have got me - after what seemed like hours (minutes in reality) nose to tail plodding, the road opens with a passing lane and I may have been a little too exuberant with the right pedal!

Arrived at the hotel around 3pm.

Parked up - between random cars; however on closer inspection these are early 2000's Ford Focus's - so my diminutive Zero is using a similar engine to them: 2 litre Zetec -  ~1.5ton Focus vs. 720kg Zero.

Good time made, went for a wander around Buckfastleigh, and a small pub crawl from The Globe to The Abbey Inn for food, and then consider the route for tomorrow - over Dartmoor and on to Penzance.

Friday, 16 December 2016

School's out for Christmas - Road Trip plans

School - er - Work anyway, all done for a couple of weeks for Christmas and New Year.

Just time for a run west towards Cider Country - Cornwall - via Dartmoor and aiming for Lands End. Roughly 350 miles each way by the time I'm done, and no particular rush so taking in some appropriate watering holes along the way.

Couple of last minute items to tweak and touch wood will be on the road for Monday.

Sunday, 4 December 2016

Clocks - sorted

Clocks came back from Caerbont mid-week;  Just re-installed this morning and they look perfect again, all the lifting decals replaced with new cards free of charge.



Typical of before/after shots - the before is in dim lighting and a little sad, and the after all lit up happy and shiny - we'll have no like for like comparisons here!

Monday, 21 November 2016

Smiths Gauges - out for repair

The decals in my Smiths Flight clocks had de-laminated; It started about 12 months in after the car was on the road and just looks untidy, all the dials are affected - speedo the worst.

The weather is nasty at the moment - so the dials are all out, about a month ago, and off to Caigauge in South Wales who makes them. The initial feedback is it was a bad batch of materials - so hopefully I get them back soon and can get the Zero back on the black stuff!

Looking pretty empty...

Update - Phone message today (25th) from a nice welsh lady at Caerbont Automotive - clocks should be on their way back to me by next Tuesday. Its taken a few weeks - but if they are right when they come back that is a result!

Sunday, 20 November 2016

Wideband Lambda - 14Point7 Spartan2

Time to upgrade the old narrowband sensor with wideband. This is partly due to continued challenges getting emissions correct for MOT, partly because its something new to play with, and significantly because I was made aware of a wideband setup with an in-build calibration mode to null out some variables caused by the install.


I'm using a Spartan2 setup from 14Point7 supplied by ExtraEfi.

I don't need a dashboard indicator - so went for the simple sealed unit.
The processing box was installed in the engine bay next to the gearbox - which should be reasonably protected from both the road and away from the hottest parts of the engine bay.

The sensor must not be detached from its cable or plug - due to built in calibration - meaning a hole in the car side panel large enough for the whole sensor to pass through. A small marine clamshell covers the hole, riveted in place for simplicity - if I ever need to replace the sensor its easy enough to drill out the rivets.


The unit has simple wiring requirements - 12v, Main and Signal Grounds, optional LED output and a couple of Lambda outputs for wideband and simulated narrowband. Sensor ground and wideband feeding into the Emerald on pins 30 and 34 currently. Best advice from Emerald is use pin 10 as the input - however its working fine on 34 so I'm not changing just yet.
I wired in another circuit for it through the main fusebox to avoid having a trailing inline fuse on the loom, while everything was open I unsheathed and re-bound this part of the loom.

The Spartan2 takes its power from the ECU relay via its own 5 Amp fuse so starts up and shuts down when the ECU does.


The interesting part of the Spartan2 is the calibration mode.
As soon as the wide-band module starts up it sends 2x known voltages/AFR readings, 5 seconds each, to the ECU. 

This permits correction for linear shifts and angle of the AFR graph, not the shape of the graph, but should factor out differences/voltage drops in installation wiring and even differences in Emerald's voltage measurement.

14Point7 supplies a spreadsheet which converts the calibration AFR outputs to two corrected points which can be input to Megasquirt ECU.

Emerald has a single decimal place on AFR, but shows and allows entry up to 3 places on voltage - so I re-worked the OEM spreadsheet to input voltages and calculate voltages from known AFR values.

Entering the calibration readings in volts, 1.642 and 3.314, in the top green boxes and the desired AFR points the sheet works out the voltages which correspond exactly to those AFR values.

Emerald does not allow selection of any voltage so the error column works out the potential error due to data entry - negligible and well inside the wide-band units accuracy.

.. Just needs copying in to the ECU settings and job's a goodun.
I suspect the wide-band has enough damping built in - so reduced the emerald signal smoothing to 0.

Gotcha - the only issue I found was by the time the ECU had powered up and connected to my laptop the wide-band had already gone through its calibration steps. The resolution was to power everything up with the wide-band fuse out, open the right Emerald Lambda screen then plug in the wide-band fuse, only needs doing once to calibrate.

Minor tweaking to restore the original powermap target AFR, and adjust the closed loop gain to get a stable idle. The idle zone used to have a lower AFR on the 500 revs column - meaning, as the ECU interpolates, its getting mixed messages - I flattened that out to 14.7 to try and give it an easier time of finding a stable tick over.

The only way to prove this is correct is a garage/MOT testing equipment - but it should be getting close & now have the controls to find the right emissions settings and have the ECU reproduce them using active feedback. I'm planning to try with a friendly garage pre MOT (next June) and if that fails a rolling road.