Friday, 28 June 2013

Projects in progress - half hood & digital speedo

Half hood

I have a couple of projects progressing currently, the first a half hood - awning type cover. I'm going to give it a go myself. Materials are already ordered from Ebay some Cordura fabric & thread; Today I worked on a simple model of the windscreen & roll bar to start to identify the shape I want & start to get a feel for the cutting pattern:

Granted paper & fabric don't behave the same way - but it helps to visualise the situation. I have slightly different fixing points to the norm, I'm not going for a line of poppers along the front of the windscreen surround:

I've not really done any work with fabric before, so no guarantee this will work; I think the next step is a mock up with some old sheets to work out a cutting pattern:

Digital Speedo

My other project is a digital speedo. Nothing wrong with the Smiths clocks I have, but I'm used to a numeric speed readout to keep on the right side of speed cameras & average speed checks.

I confirmed with Smiths that the existing 'bolt detector' speed sensor can drive another unit, so I'm playing with an Arduino Nano board and LED 7 Segment display to see what I can come up with.

My display driver is written so I can display text & fixed point numerics, Frequency measuring code also written for frequencies around 3-300hz = 1-100mph down to 10ths accuracy & I have the basic sensor circuit in place to drop the 12v sensor signal to 5v. I could do with a frequency generator to fully test my code - so either I need some more code for the Arduino to generate a known frequency using a spare clock and output pin or or hook it up to the car and see how we go.

The trick, I suspect, will be adding the right level of averaging/damping in the code to get a stable/usable speed display:

There is lots of potential here for an accurate distance/trip meter, 0-60 acceleration clock, lap timer etc

All just work in progress so far.. just depends if my mood is debugging code or sewing as to which makes progress next.

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