BennehBoy's D2 adventure

[Bennehboy]

Have just done a 1400 mile round trip to France, new tyres, rear prop, & genuine gearbox mounts made it so much smoother than before. Car performed flawlessly - although I think I need to fit a gearbox cooler as the tunnel got very hot driving at French motorway speeds in 30C+ heat.

SWMBO also got very hot with no A/C so I might look to see how possible it is to retrofit that.... OR.... get an SE body and swap it onto my rolling chassis

 

[bankz5152]

I found that as well. Cheap and quick wrapped my down pipe. Made a difference.

Id be concerned in normal UK temps/winter it would overcool the oil!

 

[resto_d1]

What did the dodgy prop feel like? I’ve got a humming, especially of coast/engine breaking around 40-60mph. I’ve just ordered front and back in a hope to cure. Wondering if what you experienced was similar?
Glad the motor performed well

 

[Bennehboy]

Humming is usually bearings - would guess in the t-case. Props are usually vibrations & or squeaks/clicks. Hope you get it sorted soon.

 

[Bennehboy]

So, I've a few jobs saving up to get done....

Fit the Gwyn Lewis Sumo bars.
Fit an adjustable panhard rod - I've noticed a slight crab on the motorway which is annoying.
Fit a thermostatic oil cooler block, pipeworks, and rad to the R380 - tunnel was super hot on the france drive, and I figure it's just got to be better for the oil and box all round if it's getting actively cooled (big tune).
Transfer case is weeping oil, it looks like it's from the intermediate shaft - those frigging o-rings!! Going to add some rtv this time.

I'll post some pics of all the bits later - still waiting on a few bits to arrive.

 

[Bennehboy]

And before I get on with that lot.....

I bought an M12x1.5 T piece with 1/8NPT take off so that I can monitor the fuel pressure via the fuel regulator temp sender port.

I'll be using the Chinese 100psi transducer that you can see plugged in, I can get these cheaply via Aliexpress and I've already written and calibrated the code to display the pressure using my Arduino (STM32) based gauge system.

Here's a pic of the breadboard prototyping setup, (I've got literally 100's of these microcontrollers - hoarder!), this one has a micro SD logging setup, Thermocouple controller for EGT, Oil pressure sensor, and some control buttons for menus. The code can handle just about any pressure or temp sensor required, all with min & max warnings, and buzzer. It can also alarm on low coolant, using the output from a BMW E30 low coolant sensor (same header tank as TD5).

I'm dusting this back off because I want to instrument the engine oil temp & pressure, R380 oil temp & pressure, fuel pressure, EGT, LT230 oil temp (no pressure as there's no pump), and Coolant level.

 

[Bennehboy]

Been farting about with the code for this project ^^, what a mess, no clue what I was thinking when I wrote it - anyhow have spent the whole day cleaning it up a fair bit - some pretty mind bending bits in there, especially the graph drawing code.

Only to realise that the device I wanted to use doesn't have enough analogue inputs for all the sensors I'll be hooking up. It's no big deal, but it just means I have to migrate onto a bigger system...

Size comparisons below:

Left to right:
Maple Mini - 9 ADC inputs - but 3 of these are used by a digital SPI component
FK407M1 - 16 ADC inputs
F407ZET6 - 19 ADC inputs

I need 8 analogue pins (1 to drive a buzzer) so it looks like the middle one is the right choice (size wise).

Anyhow, I've got the middle one working with a display and a rotary encoder for input (twiddly knob that you turn and press - like on a microwave).

Let me know if this kind of thing is too off topic and I'll stop posting stuff.

 

[bankz5152]

Nope. Really interesting. Carry on.

 

[Bennehboy]

Code is here -> https://github.com/BennehBoy/LRDuinoTD5

I'm doing some more tidying before uploading the latest updates.

Even really simple things take an age... each sensor has it's own icon, I've had to hand draw all these in photoshop, convert them to hexadecimal using a little program, add them into the code, then use a library to throw these up on the display - and they still look gash

 

[Bennehboy]

I built myself a rats nest....

This proves each of the sensor types work - with the exclusion of an earth switched coolant level sensor that I'll incorporate tonight.

You can see on the display that the max31856 is supplying the room temperature from the K-type - it's not super accurate, but close enough and proves it's working.

After that I'll get this all onto stripboard for the one off build that's going into the vehicle.

 

[Bennehboy]

For those interested I thought I'd throw in some background info.....

Working with digital devices is a lot more difficult than just plugging an analogue sensor into an analogue gauge - with those the sensor takes a twelve volt feed and returns a voltage anywhere between 0 & 12v to the gauge.

12v will fry one of these microcontrollers, at most they can handle a 5v power supply, and most of the inputs need to be 3.3v maximum.

Fortunately, most of the sensors can be driven at 5v. A simple voltage divider made from 2 resistors will then allow the output to be scaled down to the 3.3v range. Typically I use a 10k ohm & 20k ohm pair then connect the ADC (Analogue to Digital Converter) input on the microcontroller between the 2.

So that's the easy part done, now you have to do some maths to figure out what that voltage actually means....

The ADC is 12 bit linear, so that means you get a value from 0 to 4093 depending on the input. 0 for 0v, and 4093 for 3.3v.

For the boost sensor that I'm using, the spec sheet says that at -1bar boost (0 bar absolute) the output is 0v, 0bar boost (atmospheric pressure) is 1v, 1bar boost is 2v, 2bar 3v, & 3bar is 4v, & 4bar is 5v.

We know that out voltage divider basically reduces all of these by 1 third.

Given that we know that the ADC will output 4093 for 4 bar and that the range of the sensors is 5 bar (-1 through to 4 bar), we can figure out how much pressure each graduation between 0 & 4093 is.

To make the numbers easier to work with, we'll use millibar instead of bar, 5 bar is 5000 millibar. If we divide 4093 by 5000, we get ~ 1.2195 mbar per adc graduation.

So if we multiply whatever the ADC is telling us by 1.2195, that will give us the absolute pressure from the boost sensor in millibar.

To get to PSI we then need to do a double conversion. Divide by 10 to get Kilo Pascals. Then multiply by 0.145038 to get PSI.

Finally, because Boost is measured relative to Atmospheric, we have to subtract 1 atmosphere of pressure in PSI from thsi figure (1 Atmosphere being ~14.5038 psi).

The code looks like this:

  rawval = analogRead(sensor);    // Read MAP sensor raw value on analog port 0
  kpaval = (rawval * 1.2195)/10;  // convert to kpa
  boost = (kpaval * 0.145038) - 14.5038;  // Convert to psi and subtract atmospheric (sensor is absolute pressure)

And that's just 1 sensor type of the 5 that will be used.

 

[Bennehboy]

Coming to an R380 near you soon....

 

[Bennehboy]

And with temp and pressure sensors fitted to the thermostatic cooler housing

 

[Bennehboy]

Well, it was going to happen at some point, I bought an 180A welder (although it only does 180 on 415V), got it for ~ 100 quid less than they usually go for, fingers crossed I won't regret it. Draper MW190T

I'll give you all some laughs once I've collected the various other bits that I'll need to use it.

 

[Bennehboy]

I need a bigger shed.

 

[ifloochies]

I need a bigger shed.

Don't we all....
Its a never ending cycle where the more space you find, the more stuff you buy for projects you never seem to find the time to attend to, and the more stuff you keep, even from vehicles you no longer own.
Talking about myself now.... I'll get me coat

 

[Bennehboy]

Ha, don't I just know it. The Shed's still full even after a visit to the scrap man, knackered td5 head, lots of knackered gearbox & t-box bits. I need to extend the right hand workbench right to the back really as I've got a pillar drill that I need to fit in somehow.

That black metal box is my Grandad's WW2 era military issue locker box - NFI where I'm going to put that. Probably in the loft.

It looks a lot less cramped than it actually is.

 

[raywin]

Ha, don't I just know it. The Shed's still full even after a visit to the scrap man, knackered td5 head, lots of knackered gearbox & t-box bits. I need to extend the right hand workbench right to the back really as I've got a pillar drill that I need to fit in somehow.

That black metal box is my Grandad's WW2 era military issue locker box - NFI where I'm going to put that. Probably in the loft.

It looks a lot less cramped than it actually is.

Blimey I thought it was only me

 

[Bennehboy]

I bought an M10x1 to M10x1 T-piece with a 1/8NPT side tap - this is so that I can use the oil pressure switch port to T off the actual oil pressure.

The shonky Chinese ebay vendor (allegedly UK based) sent me a T piece that turned out to be an l piece, no 1/8NPT tap - no tap at all.

After much too-ing and fro-ing they refunded me 50% which I used to buy a 1/8NPT tap from the local engineers tool stockist ( Iridex Ltd, brilliant service ).

Which of course meant I had to buy a pillar drill.... (the shed shrinks further).

Here's the result, quite pleased with myself, and the pillar drill and tap might pay for themselves in about 20 years time.

 

[MikeDISCO]

Way over my head nav most of it looks like Russian but v b impressive that you have the skills to do this!
I used to work with an electronics engineer and it was like black magic when he started to fault find and diagnose problem!
Keep it coming