Air Suspension...

OK, (if anyones interested)

So far, I have collected:
10ft of nylon air line and push fit connectors
a few adapters, bits of threaded pipe etc
two analogue pressure gauges
two 5v pressure sensors
£30 gumtree 15l compressor with some hoze
5l D2suspension air tank
a mcp3008 analogue to digital convertor
few Darlington transistors and diodes (for firing the solenoids controlling the valves)

and the software is now reporting both pressure sensors, smoothing the inputs and converting them to psi.

seems to accurately sample down to a rate of 80ms, with an error of about 0.1 psi (full spectrum is about 3% for the sensors by the book)

Only thing im waiting for is the slow boat from china with my solenoid actuated valves.

Im thinking ill stick a video or two up on the EweTubes, probably wait to get the valves and install them cos right now it doesnt look all that interesting scrolling numbers.

Finally the valves have arrived!

These two are for one 'channel'. One to fill, one to vent.

I reckon i could fab something with paper mache... hehe,
Im keeping my eye out for a 2way 'analogue' system from AirLift with the proper bags and struts. do all the mech work and get air working, then once im confident the software wont kill me move the electronics and stuff into the car and final fit and finish.

or so goes the theory

EDIT:
My screen just arrived, im thinking this will be the basis of the UI. touch, 5" (mouse for scale) and only £30 - figured a digital UI would be a better solution than a button box that i dont have the skills or tools to make look pretty. pluscan be easily expandable

After new exhaust and half a tank of fuel i got to sit down last night to continue this. I will be waiting till I refactor some bits, and clean up the bodge that it is right now, before making a video

Code wise, this does what was intended for now!

The system is hooked up to a source compressor and tank, the solenoid valves are then used to set the pressure of the second (d2racing's) tank to a desired pressure.

already thinking these valves might not give a decent fill rate, the fittings maybe 1/4" but the internal bore is a couple of mm... cheap parts i guess, but for a POC id rather spend £8 a valve rather than £50+ for the 'proper' industrial valve units...

Stage 1 done!

Some little tweaks this weekend, didnt get to spend as much time as I'd have liked. But (for this test at least) the system accurately sets pressure in a vessel (coke* bottle) and maintains it (Getting better at finding leaks! ). Screen I bought has to go back, doesnt seem to display any input from HDMI from any device.

https://www.youtube.com/watch?v=FH-SqEBBHuw

To Do:
hook up to an actual airspring
control better the inrush and outrush causing the sensor to bounce
GUI (need a screen for that) (and learn a UI library for python)
Loads of code refactoring (as you may be able to tell by my massive blocks of commented out stuff!)
Scale to more 'channels'.
Mock up a load to test lifting - for fun

*not endorsed by coke, obvs.

I graphed some fill/vent cycles last night after adjusting the ring buffer (YEH its a thing!)

Blue line is the raw sensor input
Orange is the smoothed value
Grey is the tank pressure and
Yellow is the 'pressure vessel' (coke bottle)

think the balance between smoothing and response time is about good enough for now, on with the GUI! and time to get some more valves and a manifold to build them all into.