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E53 Gearbox Pressure Display

Posted: Sat Jul 26, 2014 11:34 pm
by Steamyrotter
Hi

As from another thread (Which I will add a link to here when i remember it!!)

Here is a preview of one of my little projects.
It is a Gearbox Pressure display, including voltage monitoring of both batteries...
Yes i have 2 batteries fitted using split charge..

Image

you can see it "live" on here:-

https://www.youtube.com/watch?v=4VY8cwC ... e=youtu.be


basically it is a 16x2 matrix linked to a PIC micro
The pressure is detected by a 0-16Bar (232psi) transmitter to 4-20mA loop
this is then fed across a resistor to give a 0-5v signal
This is then inputted into an analogue channel of the PIC.
The 2 batteries are linked similarly, but using 2 resistors as a potential divider to get 0-5v = 0-15v
A little bit of jiggery pokery and programming and you get this result.

Am eventually going to mount it properly in a perspex plate, along with the IPod input & Selector switch, when I can be arsed to do it........

Here is the Circuit Diagram if you are interested...

Image

Hope this is of some interest???



As an aside i also have an IBus interface that turns my Amps on and off with the radio (and turns on the RF amp for the DVD, Tuner) Will post that one day when i can get it to work properly... It sometimes misses the radio on/off command and gets it knickers in a twist and works backwards..  I think it is the method i have used to connect to the IBus, but have another method in development, just haven't got round to it yet..

Re: E53 Gearbox Pressure Display

Posted: Sun Jul 27, 2014 12:45 pm
by X5Sport
Now that's a neat little device..... :)

Ever thought of selling them?

Richard

Re: E53 Gearbox Pressure Display

Posted: Mon Jul 28, 2014 1:24 am
by Steamyrotter
Thanks Richard.
I wanted to have it a little inconspicious and useful.

Not thought of selling them but if anyone wants one can try to see what I can do..

admittedly most expensive part is the pressure transmitter but have found some at a reasonable price!!

Re: E53 Gearbox Pressure Display

Posted: Mon Jul 28, 2014 10:42 pm
by Spartanx5
That's a great little idea. Did you base the process on a system from another car? I've not seen oil pressure monitored before!
I dropped my x5 off at bmw Peterborough this evening, I was not impressed, so far £136 for the diagnostics apparently,  and the blonde teenager with a nice top half if I do say so began by quizzing me for about 10mins to get a grip of the cars symptoms, I hate companies that do that, If you have the knowledge of a system and equipment you should be able to find to ANY problem, as an engineer I find I prefer people to give me as little info on faults as possible so I can look for them whilst checking the whole system is doing what it's supposed to, I know you can save time by getting the client to tell you what they think is wrong BUT it creates the opportunity to skip stages and look at certain things that may not even by anything to do with the actual fault. Where are all the good old fashioned techs gone that have routines. What's the bet there is only 1 expert in that garage and he will be on break while my mine is on the ramp. I will get the 18 year old school leaver who can only just spell BMW. Sorry guys, bit of a rant I know but I do love that car.

Cost to date:
£1300 new timing chain gaskets and major service
£1400 new wheels and tryes
£250 oil leak and water hose replaced
£136 and counting diagnostics

Not that much but don't forget I only brought it around June time!!! >:(

Re: E53 Gearbox Pressure Display

Posted: Mon Jul 28, 2014 10:53 pm
by Steamyrotter
I based it on the fact i wanted to see the box pressure so i know whats happening.
Had too many issues with this box so any info is good.
The battery monitoring was because i wanted to make full use of it rather than just one reading.
Was thinking i could put a selector switch in to display other readings.. But couldn't think of any others i wanted to look at at the time...
Still can add that on at any time..

Re: E53 Gearbox Pressure Display

Posted: Tue Jul 29, 2014 5:46 pm
by Spartanx5
Monitoring the battery on the x5 is a great idea, bmw called me today there was 22 faults in the memory when they tested, I have had them cleared 3 times before it went to bmw. The last time was 4 days before I sent it them. I think it pretty much confirms it's the alternator! The only common fault that has came up is under and over voltages. The others all are little electrical ones, such as speed sensors on all corners etc. They did say I need a transfer case oil change so I am going to let them do that while they are there, the tech said the alternator was a bastard of a job because they are water cooled, is that right or are they just trying to prepare me for another stupid bill.

Re: E53 Gearbox Pressure Display

Posted: Tue Jul 29, 2014 6:30 pm
by Steamyrotter
They are watoer cooled and squeezed in under everything..
not an easy thing to reach let alone trying to change one..

I am dreading that job....

Re: E53 Gearbox Pressure Display

Posted: Sun Aug 03, 2014 12:08 am
by moar
[quote="Spartanx5"]
If you have the knowledge of a system and equipment you should be able to find to ANY problem, as an engineer I find I prefer people to give me as little info on faults as possible so I can look for them whilst checking the whole system is doing what it's supposed to, I know you can save time by getting the client to tell you what they think is wrong BUT it creates the opportunity to skip stages and look at certain things that may not even by anything to do with the actual fault.
[/quote]

I laughed at the ridiculousness of what I just read.

10/10 would read again.

Re: E53 Gearbox Pressure Display

Posted: Sun Aug 03, 2014 11:51 am
by Spartanx5
There're is term for people who agree with cutting corners Moar, I like to call them cowboys. I'll make sure I keep some hay out for your horse.

Re: E53 Gearbox Pressure Display

Posted: Sun Aug 03, 2014 11:54 pm
by moar
Armchair auto mechanics/engineers. Gotta love them.