Arduino Project - Car coolant level indicator - Volvo V50 T5 AWD

Most cars, as they get old, tend to die a death from overheating. 

A lot of the overheating happens because the rubber hoses get brittle and fissure and at pressure they tend to break and let go all the coolant.

Depending on how that happens, which one it happens to and how zealous you are to the temperature gauges, you can be lucky and catch it in time, be distracted and catch it too late, or just be unlucky and have one of the lower end hoses go and not have a chance to catch the issue before the engine overheats.

Some cars are equipped with a coolant low indicator... but others aren't.

I was very surprised and UPSET at Volvo, when I found out that my 1997 v70 t5  HAD a coolant lever indicator, but the 2006 V50 T5 AWD from my wife didn't!

My guess? somewhere along the line, (as Ford purchased Volvo) an economist on the management team, bossing the engineers decided to take 20cents profit for sensors and not install it, unlike the engineers had designed and used for decades... the usual in today's business world. He probably also thought that, as the engines started dying on their customers, they would just buy more cars... instead of changing to a better engineered brand!!! This is what happens n'our days. Economists in power.... bad decisions all the way.

However I'm and engineer and I would never accept this sort of quality reduction... so:

I went on ebay and Amazon, and brought the following list of recommended parts:

https://www.amazon.es/ELEGOO-Microcontrolador-ATmega2560-ATmega16U2-Compatible/dp/B06Y3ZHPWC/ref=sr_1_7?__mk_es_ES=%C3%85M%C3%85%C5%BD%C3%95%C3%91&dchild=1&keywords=elegoo+mega2650&qid=1626133196&sr=8-7

https://www.amazon.es/POPESQ%C2%AE-Raspberry-Generador-Frecuencia-Frequency/dp/B06XVQYF3N/ref=sr_1_5?__mk_es_ES=%C3%85M%C3%85%C5%BD%C3%95%C3%91&dchild=1&keywords=arduino+passive+buzzer&qid=1626133228&sr=8-5

https://www.amazon.es/Vosarea-Charger-Adapter-Charging-Voltmeter/dp/B07YYYP2SH/ref=sr_1_8?__mk_es_ES=%C3%85M%C3%85%C5%BD%C3%95%C3%91&dchild=1&keywords=usb+to+12v+car&qid=1626133271&sr=8-8

https://www.amazon.es/AZDelivery-128-160-p%C3%ADxeles-91-OLED/dp/B078J78R45/ref=sr_1_2?__mk_es_ES=%C3%85M%C3%85%C5%BD%C3%95%C3%91&dchild=1&keywords=oled+128%2662+i2&qid=1626133375&sr=8-2

https://www.ebay.co.uk/itm/383588215448

Did I need the MEGA instead of a simple UNO? NO! but since the car is t be driven by my wife and the Display should be more informative I added the Oled Display.. that oled display (plus variables and libraries) consume A LOT of ram and the UNO doesn't really cut it. However if you are to simplify things with a simple warning and buzzer, the uno is more than enough.

So being a Polestar V50 T5 AWD and having an oled to fool around with, I've added a couple of boot logo and boot info before the real stuff. The code is here for my example and should be adapted to your own usage. 

Describing the circuit:

The liquid level readers are glued with something tough (I recommend T-REX) on the top level and bottom level of the expansion tank.

I recommend you to run a 4 wire cable all the way from the arduino place within the car to the engine bay... one for ground one for 5V and 2 for 5V return (one per sensor).

I also recommend you to create a simple oled placeholder with a 3dprinter, or use a dremmel to grind the oled location within the dashboard, assuming there is space for that. 

I recommend you to place the oled in front of the existing dash on a non obstructing part of the dash, and the buzzer behind it, so it send the audio buzzing to the dashboard and this amplifies and reflects back to the driver. 

Evidently the red warning led should be placed in front of the oled.

Then It is rather easy. On my code I've setup variables according to pins, you can change those and have your own project divert.

Arduino Digital IO 4 - wire to positive terminal on the buzzer

Arduino Digital IO 5 - wire to positive LED terminal arduino relay

Arduino Digital IO 6 - wire from Lower fluid level sensor RETURN line

Arduino Digital IO 7 - wire from Higher fluid level sensor RETURN line

Arduino Communication IO 20SDA - Oled SDA

Arduino Communication IO 21SCL - Oled SCL

External 5V supply:

             - Liquid Sensor 1 Voltage and ground

             - Liquid Sensor 2 Voltage and ground

 ***you can power the sensors directly on the 12v car supply, but then you need a voltage divider on the sensor return line to the arduino. I find it just easier to run a 5V supply on the sensors and reduce circuit complexity and add stability, as cars can output anywhere from 11V to 14v, depending on rpm.

Arduino 5V :

            - Oled VCC

Arduino GND:

            - Buzzer Ground

            - Led relay Ground

12v-usb car adapter, to Ignition 12V and car ground... and then a usb cable on to your arduino.

Led :

            - ground to car ground and 12V to arduino replay module, then from replay module to ignition p1 power (a.k.a. - radio power).

Logic is as follows:

- show volvo + polestar logo on boot

- show car setup (power and AWD)

- enter loop mode with coolant level display

-If all coolant levels are good the return value is 2 and display that everything is OK

-If only the lower level is returning signal, then a refill message is displayed

-if both sensors are not returning, than coolant is bellow threshold and a Stop the car" message appears together with an annoying buzzer.

- if top sensor is returning value but the bottom is not, something is off and a "check system" message is issued with a less annoying buzzer. 

The code and STL file can be found here:

https://github.com/mr1b31r0/ArduinoCarCoolantLevelWarning/tree/main

Some pictures of the project with some oled display  info:

The enclosure (stl and cad files in github, together with the code).

 

 

First Assembly - buzzer + display + enclosure:

ground for display is shared with buzzer :) one less cable.

And a some poliurethane glue to bind things:

Next is the relay for the 12v bright led light:

The connectors on the Arduino board:

And a small test drive:

Installing:

 

Setting up the Relay module and led light (12V):

 

Sitting the Arduino in the car and pasing cables behind the climate control units:

 

The sensors and some tests:

 

 

 

The final install:

 

Why I've just declined an apparently brilliant deal? Seagate is why!

I've been working in IT since 1995! well officially, unoficially it dates back to 1986.
But with RAIDS, since 1997... I've worked with a number of hard disk arrays and vendors, since becoming certified in storage by HP, back in 97 or 98.

Yesterday, a good friend called me with a flash deal. 6x 8TB sata HDD for 600 euro! New!

I was inclined in taking it, but then I decided to make the smart question: Hi Harry, what's the drive brand?
The reply was: Seagate!
And I've passed it! Naturally.

So why!? did Seagate, the makers of some of the best drives I've used back in the ATA and SCSI days?

I work with around 19 RAID at work and 4 at home... all running 24x7... and I've recently been over a simple statistic on hard-drive failures that is just explanatory:

Hard Drive Fail per brand 2.5" and 3.5":
Seagate - 98%
Samsung - 70%
WesternDigital - 3%
Hitachi - 0%

Hard Drive Fail without possible software recovery within 1 week of buying:
Seagate - 90%
Samsung - 0%
WesternDigital - 0%
Hitachi - 0%

Hard Drive Fail within 1 year of buying 24x7 NAS or RAID usage:
Seagate - 8%
Samsung - 60%
WesternDigital - 0%
Hitachi - 0%


Hard Drive Fail over 1Year and suffering a Datacenter cooling failure (one of the best ways to loose the reading head on a hard drive):

Samsung - 10%
WesternDigital - 2%
Hitachi - 0%

Hard Drive Fail on USB hard-drive with over one year and backup-restore with moving between locations :
WesternDigital - 1%

Now comes the conclusion:
Clearly, if you want to sleep at night, you will NOT BUY SEAGATE! Easy One!
But is the drive failure a quality problem or mis-usage?

Well the remaining 2% of hard drives are equals of most the ones that failed, operating under the same circumstances over similar periods... and one of the failed drives is a "Seagate constellation", operating under redundant temperature controlled datacenter, and used for backup, and not high load... so clearly a quality issue.

Today, If Seagate offered me HDs for free, I would just go pay and buy some Hitachi or WesternDigital... hell those, I would even buy second-hand and be cool with it.

Samsung... well let's just stick with silicon as they clearly are better with SSD than mechanical drives... still, they've managed better than the industry giant Seagate.

Blackberry Z30 end of Whatsapp support...is easy to solve

Hi all

If, like me, you are a Blackberry 10.x user,  you have probably been using FastTube for years not... not not and gave up like me... and then a couple of nights ago, was forced to stop using Whatsapp.
That annoying "switch to a supported device please" message that makes you furious to the core.

I've always been an android user... I have 3 android phones, 4 android tablets... and I must say I can live with android (normally after removing the operator and manufacturer bloat-ware)... but my side kick? my pocket secretary? that's the blackberry. It's always been, and I really hate that the community "try and force me out of something without first building something better for me to move to".

It's an easy (economics like) step to say "whatsapp is free, you need to use the devices we tell you to use"... but there is a reason why brilliant people are taught engineering at college instead of economics.

I hate those "non engineering, all economics, brainless decisions" and I also love a good challenge. So I took 5 minutes to digg deeper into this.

So sure the BB whatsapp is no longer supported... uninstall that crap, it will never work again.
However, the brilliance of BB system 10.x is that is has embedded android libraries as standard. That is why you can download .apk files and run it.
The problem is that most of those libraries are accessed by the GUI and the GUI from BB was built to use it's own functions.

Solution? Well why not installing a GUI manager for Android. Grab the "Nova launcher" APK and install it. All you need is to have BB OS 10.2 up... I'm using 10.3. The other APK you really need is the Playstore apk. Even if it does not run, some APK's check for it at launch so "being there" is important.

One of the apks that you can install is the Watsapp apk... and believe-me... it runs perfectly.

No need to buy a new phone... just to digg into the BB OS10 project and be amazed with the similarities between the 2 xNIX platforms and their respective support framework.

Long live BB10

The House of an audiophile Part 2 - The Cinema and Games room

This article is pretty useless without first reading the Part1, so if you haven't read that you will not understand the whys in this one.

Ok so I dealt with the first part of the problem with Part1... but that still leaves me with the even bigger, even more asymmetrical, prone to echoes and natural amplification of sound Cinema and Games Room.
There is another catch: the living room was supposed to have good sound, but this has to have good and powerful sound! If I'm having a party, this will be the disco.

The geometry, already discusses in Part 1 is...

...challenging.

So, again, after several tests and trials, and the obvious usage of my Galaxy Alpha phone as a sound analyser, I managed to sort things out this way: (for the geeks sake, I'm starting will the schematics and all the goodies, and I'll explain as I go.

 OK so this is far more complex (starting with the inputs... being a cinema and game room and all)!

The inputs start with the so full of glamour and on of the best CDPlayers EVER made the Nakamichi CD2P-E. This thing has been recapped and ouptup XOver trimmed so that all the possible musical details are pickup. This is an example of why a good old 16Bit DAC CDPlayer can eclipse an modern 24bit DAC cd player... I could talk for a year on this, but in very simple terms, think that the analog sound wave that you hear, once digitized is converted to a sort of bar chart of what the music would look like. Obviously, this loses resolution and that is why a true audiophile prefers vinils to CD's.
However, there are some excellent designs out there that can "imagine" the gap between the bars and recover the lost sound-wave. Some are good.. some are great and some are gods.
So in this sense, more bits = more resolution = better sound...no! CD's where recorded with a specific bit-stream in mind... having more bits does not mean that you have more resolution out of the CD, but rather you can decode more at once, and that allows you to have a bit-stream comparison on the recreation of the sound wave that could reduce conversion error.... so a 8 parallel chip 16bit circuit will easily eclipse a state of the art 24bit DAC (if the 16bit chips are really good).

Back then, while Philips created the TDA1541A 16bit DAC chip (and they did a VERY good job at that), they also created what is called a reference diagram, so that integrators could follow and create their own design. These diagrams normally are a schematic build to make the chip work and they are build long before the chip is made... so, by other words, no one ever tested the diagram.
Pioneer, sony, and all the other except Nakamichi and Arcam, decided to copy-paste the schematic and sell cd players.
Did it work? yes! Where they any good?.. no! they where all mostly dull and flat. Nakamichi and Arcam, however, waited for the chip, built their board based on the reference but not blindly, and then tweaked the output and voila! They unlocked the secrets of the brilliance of Philips TDA1541a chip design.
It is one of the best DAC out there!

The CD2P is rare for being very pure and precise in sound image, and shows you the best details in sound. It's that sort of player that makes you re-listen to all your collection because there was just too much you where missing.


As usual, loving he best ever build and being a child from the 70's-80's, I have my Amiga 1200 Tower connected to my media sytem.
You can see it here:

The rest is the typical Nintendo Wii, a Sony PS3 and a Roku3.

The AVR:

The AVR is a Denon4306... a true beast

This, is directly driving the Front L+R, the Midle L+R and the Rear L+R... and then it pre-outs the subwoofer and the Rear and Center channel to a set of slave amplifiers. The direct drive from the Denon outputs 8Ohm at 130RMS watts, and given the generous size of the capacitors, it's no wonder it can drive the speakers without getting tired when a lot of bass kicks in. The Denon has a capacity to resist starvation that is not all that common.


The central front slave to the Denon is no less than a Marantz PM55SE... yes it is a Ken Ishiwata tuned PM55... special edition.
A beauty...with a total harmonic distortion of 0.02%

This then drives directly a pair of B&W DM305. The 305 was an interesting project.
B&W where on the quest for a deep bass speaker made form light materials, that could reproduce across the range and not suffer form brittleness form the light materials resonance, and still provide some bass.
They created a Prism design backplane for the speaker that mimics the attenuator foam form the walls of any sound proof room.


























Did they succeed? NO! the bass is to soft (probably attenuated by the prism), however, they are EXCELLENT to reproduce voice channels... like the typical "dialogue" assignment that a THX system enrols the central channel into. So an initial deception as main speakers, transformed into a solution for the central channel. Driven by a powerlfull bu low distortion amp.


Back to the Amps... so I talked about the front, so how about the reinforced back?
The room architecture meant that rear needed power, so instead of buying extra big speakers and loose HIFI, I chose to spread the frequencies across multiple speakers and make a "sound wall".

Welcome to my faithful Marantz PRO PM4400

 

 Once again, I turn to Marantz this time seeking power and precision.
This beast is directly driving:

 The Mission 773 pair and the Celestion Impact s1 10"sub

The Missions will be talked about soon enought, so let's look at the celestion! This 10" driver with it's own poweramp and XOver, is able of going below 30Hz (normally you would go for a 12" and more to run below 30hz). we can;t however forget that celestion is the brand behing most rock concerts speakers, the bass stations on most dance clubs and, last but not least, a major builder and suplier of drivers for other speaker manufacturers.
Yes, their driver can go bellow 30Hz and still be able to go up to 150Hz because of the stiff and light construction.

 But we are not done with the Marantz PM4400 yet.... out of the back of the Celestion, Xover to 150Hz and up, there are a couple of Mission 772 on a pair of ATACAMA stands.

 Now lets look at the speakers that the Denon drives directly:
Starting with the back (since we where already there), a pair of Mission 774

 On the Middle we have a pair of very powerfull and robust Wharfedale XARUS 4000:

The finally, the best sounding speakers for the money ever built, driven direclty by the Denon on the front R+L channels, a pair of Mission 782.
These are very peculiar speakers that have a very interesting history, please read all about it here.

We can't forget that the mid-to low bass is output by a KEF 1000.2

 

 The result? please have some pictures:

 

This is a Video of the Sound quality and image, with "The Verve's - Happy Man" brutal guitar:

Here, it is clear that the camera mic is on the limit with just a simple guitar playing as -20db, and when I up to -10db is just distorts the pickup sound. But believe-me... the listening experience is flawless if you have ears instead of a cheap MIC.



And this is a video demonstrating how easy this handles pure bass, at volume, without distortion or brittleness:

Without surprise, the Mic is not able to perform at -20db with a bass full music, the 10db is just pure distortion on the MIC.

However, looking at the graphs several conclusions can be taken on both videos:

1. The system is reproducing at 24hz frequency and performs all the way up to 20khz without gaps
2. When the volume is increased, the system increases db's without compromising the frequencies... they all grow proportionally.
3. The Bass (hard to equalize) is maintaining the volume without gaining HUMMMMsss or becoming excessive.
4. The volume at -20db is enough to overwhelm a Splash Action cam's mic...with rock!
5. The 772 and 773 speakers are operating near the limit on the -10db with bass sound, I'll try to attenuate this in the future, so i can go all the way up to 0db and eventually end up without windows in my place :)

Now about the Missions... all the 772, 773, 774, 782... together with my M73i,  V62 and the Mission built Denon SCM51.

Some would ask, do you have a mission fetish?
No! I have an engineering over economics fetish... that's why.
It's easy to grab the best materials out there and, not minding cost, build a decent speaker that the client would buy for gazillion euro and perform nicely!

Mission is that brand that (in the old days) invested a lot of engineering time trying to create a speaker design that performed the best, and then try to replicate that design with materials that would cost less, so the client would not need to overpay (sometimes this came back to bite them, but some years in and a small research can turn this around in your favour... see my Mission 782 article).
The result is that most OLD missions sound better than their price range. But every now and then they build a product that rockets out of their standard into stratospheric performance.
The 782 is an example of that! It sounds better than speakers costing 10 times as much. Much like the M73i and V62 (after properly sanded with a minimum 2kg of sand) can sound better than speakers that cost 4 to 5 times as much.
The 772, 773 and 774 are a family of speakers that are excellent performers for the price... but within this family, the 774 is the excel. It just sings through the entire frequency range without a fuss.... it's far better than the cost.

Why? Well, just like B&W has John Bowers, Marantz has Ken Ishiwata, Mission had Peter Comeau.
Most speaker I buy are designs produced by or supervised by Peter Comeau. We seem to like the same things and that is very good... plus I love the idea of not paying for others laziness (nor marketing... hence not owning a single Bang&Olufsen).


Hope you like this article... more will follow are there are 5 other audio systems that make me very happy and proud... and will make their way into the next 5 articles, so stay tuned.