In-Dash (Cluster) Boost Gauge

tongsli

Top Post Dawg
Joined
Jan 31, 2000
Location
Baltimore, MD
TDI
2000 Jetta TDI, 2004, Jetta Wagon TDI PD
Try searching. There are ALOT of TDI guys who have this cluster. A few that come to mind:

Oldpoopie
PeterV
Torkin Dog
TDI never die
Coolwht
Occam's Razor

L
 

ShokWaveRider

Vendor
Joined
Apr 17, 2003
Location
St. Augustine, Florida
Hi All:

I am back from vacation. I am actually in Toronto Canada for a few months. I am only doing boost gauges to special order now. I do not advertise at all and will be off traveling for a few months again come October/November. So any Canadians that want any work done let me know. Email me if you need any questions answered. There are lots of references here on this site.

I am also considering selling the business complete if you know anyone.... Probably to much work for the average person though. Just a thought.

Happy boosting,

Ian
 

TorkingDog

Veteran Member
Joined
Oct 22, 2002
Location
TAXachusetts
TDI
Jetta, 2003, Silver
I would highly recommend this mod for anyone who is looking for a really cool boost gauge. Ian installed mine in a MFA cluster utilizing green, yellow, amber and red led's for a 25 psi unit. Ian's workmanship and quality service is outstanding!
 

BrentB

Veteran Member
Joined
May 29, 2003
Location
Calgary, AB Canada
TDI
Golf, 99 1/2, Black
I would be interested in seing the schematics but thats about it. I think I am going to finally get to work on my gauge clusters that read right off the ECU electronicly rather then using an analog signal. More guage options and very easy to set up.
 

EECSentric

Veteran Member
Joined
Mar 21, 2004
Location
Arlington, MA
TDI
2015 GSW TDI SEL DSG LP
I really like the boost gauge behind the tach. It would be cool if you could have two needles, one red and one blue on top of each other (like a hour and minute hand) but that would require some major rework I'm sure. Ian did an excellent job of showing how to do the install.

[ QUOTE ]
I would be interested in seing the schematics but thats about it.

[/ QUOTE ]

It appears that he used Express PCB to design and fabricated the PCBs. If he had 20 of them made with the standard service (no silk, no mask, 2 layer) it works out to about $9/pcb.

[ QUOTE ]
I think I am going to finally get to work on my gauge clusters that read right off the ECU electronicly rather then using an analog signal.

[/ QUOTE ]

The reason for using the analog signal is that it is very easy to build this type of circuit. Although all of the pictures of the circuit do not show any part numbers, I would assume that the LM3914 (a very standard dot/bar display driver) is the heart of the circuit. It has provisions for programming LED current (for dimming) and for cascade operation. The LM3914 has a linear output scale, while its brother (the LM3915) has a logarithmic scale. The main issue is just making sure to not load down the input signal (guess IC3 is an op-amp buffer of some kind) and to properly calibrate the entire unit (since it is analog). The LM3914 datasheet has an excellent set of application notes.

I don't think the board itself is worth the current $265 price but there was time invested in its design and significant work at providing excellent installation instructions and photographs.

However, the time it takes to actually do the full install and the workmanship and quality that the photos show, now that is worth the price. I think many people would be hard pressed to do such a good install of this kind of kit and that is where the money goes.

BrentB, the nice thing about reading from the analog signal is you know it's pure. So regardless of what happens to you're ECU, or which ECU is being used, your boost guage will always be correct and will be updated at the fastest possible rate (which is what is needed, right?)

Ian, could you share the schematics with us? Possibly using a Creative Commons licence?

I'd really like to build this, but I've got to finish my car computer first. I'd set the display up in three ranges, dim blues for the low and medium range and red for the higher danger zone (over 18psi). It would operate in dot mode in the low range, then switch to bar mode in the mid range. If the input overranged, the I'd set the display to flash. It's all in the data sheet. Digital electronics are cool and all, but analog is heaven in some cases. I'd suggest using clear or frosted case LEDs in any case, as I don't like the non-stock look of yellow or green dots. What would be even better is if the LEDs were placed behind the faceplate and the drilled holes were covered with a translucent material to give it even more of a stock look. Oh, an alternate mode of operation that would take a little more work would be a full bargraph but with a peak dot with decay.

Comments? Ideas? Anyone interested?
 

billmn

Veteran Member
Joined
Nov 13, 2003
Location
Minneapolis MN USA
TDI
2010 JSW stock:Totaled 2000 black Golf gls 315K : retired
I would LOVE to do this mod, I would be willing to build the box myself if needed (and if it would save some $$). I have been trying to figure out a decent boost gauge but don't want a separate gauge off the cluster.

I like the idea of putting the LED's behind so it has a more finished look, the cover of some kind (so it looks more like stock) would be a GREAT idea too (especially if someone could print up the numbers on it /images/graemlins/grin.gif)

Bill
 

EECSentric

Veteran Member
Joined
Mar 21, 2004
Location
Arlington, MA
TDI
2015 GSW TDI SEL DSG LP
billmn,

I am working on it. I just finished a preliminary design and posted it online at http://tdi.elysianaudio.com/turbogauge.html . It is not quite finished because I need someone to answer the question of what is the MAP sensor output look like and how is it calibrated (posted question in this thread here).



If at least 10 other people are interested in the board, I'll do a batch order. But you'll have to wait a few weeks till I can prototype it up just to be sure. I'd say by far the coolest addition to my design is the decaying dot peak indicator on top of the normal bar graph. More information to go up soon.
 

arootbeer

Veteran Member
Joined
Sep 14, 2002
Location
Austin
TDI
2003 Jetta Wagon GLS TDI White/Black
It's my understanding that the boost should be taken from the upper intercooler pipe near the manifold, not from the MAP directly. IIRC, Ian's solution actually uses an air line tube to get boost pressure from the system.

(Of course, this is all from memory, so I may be off a bit).

Edit: After reading through his documentation, it states that you can use either the onboard MAP, or a separate MAP. However, for highly boosted cars, you'll need a 3-BAR MAP to see anything over 20 PSI. I did a quick search for these, and they seem to run about $90.
 

ShokWaveRider

Vendor
Joined
Apr 17, 2003
Location
St. Augustine, Florida
I would use a Motorola MPX5700ap which is actually good to 101psi but you only need to use the first 44.7 psi of 14.7+30.

MPX5700

And, it can just be connected into the car's vacuum line for ease of installation.

Then you could can the jumper settings and adjustments, so all the units (PCBs) would be the same from a component perspective.

My circuit is actually a lot simpler that this, but each unit needs individual calibration. Making construction time a little longer. I did mine for compactness in order to fit into a 3x1.5x0.5 enclosure. The complexity is the installation into the dash as opposed to the circuit.

Nice Job, has it been tested yet?

Ian
 

ShokWaveRider

Vendor
Joined
Apr 17, 2003
Location
St. Augustine, Florida
Oh:

I forgot, I have over 300 1.8mm Blue and Amber LEDS that I had specially made. Red, Greens and Yellows are readily available. They are made by Lumex and Digikey charge $7.50 each as a special order and you have to buy a lot. I paid nowhere near that.

Ian
 

billmn

Veteran Member
Joined
Nov 13, 2003
Location
Minneapolis MN USA
TDI
2010 JSW stock:Totaled 2000 black Golf gls 315K : retired
Depending on the price I would be VERY intrested in a group buy on these. Anyone with any good ideas on mounting the LEDs behind for a more finished look?

Bill
 

EECSentric

Veteran Member
Joined
Mar 21, 2004
Location
Arlington, MA
TDI
2015 GSW TDI SEL DSG LP
[ QUOTE ]
Anyone with any good ideas on mounting the LEDs behind for a more finished look

[/ QUOTE ]

I'm thinking about it. Here is a sort of plan. Drill the holes in the same way as shown above, but don't put the LEDs through the holes. Instead, put the LEDs behind face plate, tacking them in place with a little super glue or what not. To save on depth, SMT LEDs could be used (hopefully the same color as the blue/red backlight LEDs). Fill in with black silicone caulk (or something), solder the whole mess up (same procedure) and cover with more caulk. Once the whole thing dries, flip plate over and hold it in some setup so that the top is very level and stable. Then, VERY carefully, fill in each little well/hole with a medium viscosity translucent material. I'm thinking a simple superglue would work. If done just right and slowly enough (tapping the surface to get out air bubbles), this would create a small plastic window effect.

Sound reasonable.

So here is my question, where can I buy/find extra tach gauge faceplates? I'd like to get a few to practice on and also to play with before I pull the dash apart.
 

billmn

Veteran Member
Joined
Nov 13, 2003
Location
Minneapolis MN USA
TDI
2010 JSW stock:Totaled 2000 black Golf gls 315K : retired
I did a quick search on Impex and did't find tach faces. How about at junk yards? How about on vwvortex, after people upgrade their gauges wouldn't you think they might still have their old ones just laying around? Just a though

Bill
 

EECSentric

Veteran Member
Joined
Mar 21, 2004
Location
Arlington, MA
TDI
2015 GSW TDI SEL DSG LP
I wanted to order parts for the prototype tonight, but I noticed a pretty major error in the schematic (as in I was being silly with one of the op-amps) and I have just corrected it and uploaded the new schematic file to my page. After I verify operation on a breadboard I'll bother with updating the PCB layout. I could very easily shrink this down significantly if I went with all surface mount components, but something tells me most people don't have a microscope & Metcal iron at home so I'll keep this one big.

Ian,

Thank you very much for you're help. I think that Mot part is pretty cool and defintely easy to use. It's only $15/unit from Arrow, so I'll probably purchase one to play with. Is there any benefit of putting in an independent pressure sensor instead of just splicing into the existing signal?

Ok, here is the next question. I think I'm going to try to use size 1206 surface mount LEDs for my gauge display. Does anyone know the actual wavelength for the VW gauge colors (the red and blue)? I'd like to match as closely as possible.
 

ShokWaveRider

Vendor
Joined
Apr 17, 2003
Location
St. Augustine, Florida
I had so much trouble with Surface mounted LEDS. They are so fragile and break easily. People had so much trouble with the installation. They were VERY hard to mount in the Dials. I still recommend the 1.8mm units, if only for their longer and thicker leads. Again, I had to have the blues and Ambers specially manufactured.

I ended up using external sensors unless I was installing them myself in the car as people found it a lot easier. As far as the 25 + units the car's sensor only goes to 22psi.

I think you will have a lot of problems fitting 30 LEDS and their wires into the cluster. I have done over 100 units around the world. People simly do not want to drill their dials and solder the LEDS in let alone the wiring. The cost is in the work to get the dial looking somewhat professional and stock. Not in the electronics. I simply offset a bit of the installation cost by increasing the cost of the electronics. It would be impractical to charge $3 - $400 for the installation. The original 3bar MAP sensors used were $90 each cost. The LEDS (Blue) were $4.50 cost if you had 500 made or $7.50 if you got them from Digikey. I had to wair 4 months for mine from Asia.

As I am winding down the business now, I usually drill the Dials and install the LEDS and cut the leads to size for people. and Provide the electronics for a reasonable fee. I do nor really want to do the installation any more unless I have to. And hence the cost.

I will still offer the service of the Board and the LEDS. for the 20 or so Boards I have left.

But from a commercial cost perspective. Here are the numbers at my cost for you to evaluate.

The Board complete and calibrated including 1.0 hours labor shipping of parts, etc. is about $100 - $125 No sensor, LEDS or wiring or enclosure etc. The time to do the cluster is between 3 - 5 hours of anyones time. MY average (Non Web) price is between $299 and $399 (No Blues) All done. Looks expensive but for the work is not bad. (ask Tongsli) If I did an AF Meter at the same time it worked out quite a good deal on the time as it takes a similar amount of time to do the AFM as it does for the Boost.

Your board will cost more than mine as it has 2 x the parts. I do not know about calibration. Mine took about 30 -40 minutes to calibrate to +/- 0.250 Psi (from and electronic perspective)as all sensors are slightly different and I was picky about it. All my important resistor values for calibration were down to a 1 Ohm tollerance. I do this by selecting the resistors for each sensor and chip set. I did also use Military spec chips for some applications.

Somewhat expensive yes. But in all honesty I would not do the installaton for less than $200 + all the parts. It is a lot of work as people will testify and you only have ONE DIAL!

Good luck with your project and have fun drilling. I think very few people will want to do the install themselves.

Ian
 

EECSentric

Veteran Member
Joined
Mar 21, 2004
Location
Arlington, MA
TDI
2015 GSW TDI SEL DSG LP
I absolutely agree with you about the installation. The wiring of the cluster is incredibly difficult to do and as I said, I think that even by your website price, $470 is cheap for the amount of time and precision that you put into the project.

I figured on making the first rev board to be as expandable as possible, so although it can handle 30 LEDs, I'll probably only install 20. I may wire up one of the outputs to an audio alarm as well, or at least put in provisions for it. The more I think about it, the more I'd rather go with all surface mount parts for size and cost. But if I go SMT, I could make a board that had solder points for the LEDs as well. I don't know, I'm really just planning things out for the most part but I did order all my prototype components last night.

I'm thinking about how one could rebuild a custom face plate. I can get access to a water cutter and I was thinking if printing a display with a good color printer could actually look good. Please take this paragraph with a bucket of salt, it's just me thinking crazy thoughts.

I have a major history of taking projects to the (n+1)th degree.
 

Vroom

Veteran Member
Joined
Dec 5, 2000
Location
Windsor, Ontario
TDI
mrrobmora
[ QUOTE ]
billmn,

I am working on it. I just finished a preliminary design and posted it online at http://tdi.elysianaudio.com/turbogauge.html . It is not quite finished because I need someone to answer the question of what is the MAP sensor output look like and how is it calibrated (posted question in this thread here).

[/ QUOTE ]
I made one using my MAP, but I might switch over to using an external sensor like Ian suggests, because the OEM one doesn't have enough range. For now though, I don't really mind. Anyway here's a pic of the board: (I haven't had the time to install it permanently yet though).

Only 20 leds, and two potentiometers to adjust the range, and another two for the brightness (day & night).
 

ShokWaveRider

Vendor
Joined
Apr 17, 2003
Location
St. Augustine, Florida
I notice a lot of POTS on these boards. I tended to steer clear of pots as they do drift. I found that fixed resistors and calibration were the way to go. And also wgen you adjust the brightness on the chip, it changes the scale somewhat. So I went with current adjustments to the LEDS. THis also gave a common Dimmer to the complete array.

Ian
 

BrentB

Veteran Member
Joined
May 29, 2003
Location
Calgary, AB Canada
TDI
Golf, 99 1/2, Black
ECCsentric still think ecu stignal is the way to go as I also want to have 7 seg readouts for oil pressure and maybe intercooler temp or something along those lines. If I remmeber correctly industreal LM3914's are used in that other design as there is less drift over temp range and they are a bit more accuate. If I do go analog signal I am going to use an op-amp input to a pic with a ADC and use a 7 seg readout and put it in the center area of my cluser or something. With the opamp it will be easy to adjust. Or I can just use a secondary boost pressure sensor but they are price at about the 25$ canadian mark. Circuit boards are cheap for me as APC is in the town I live in and they do cheap prototype board runs. I also prefure to work in surface mount as I have a large stock of all types and sizes and that is what I work with all day long. I will have a look over your website and see if I come across anything interesting. Feel free to shoot me a msn or email if you want to bang more ideas around.
PS if you want a prototype board done I have a CNC machine at work that I can mill a board out on so let me know.
 

oldpoopie

Vendor
Joined
May 14, 2001
Location
Portland Oregon
TDI
2001 golf gl, 2006 jetta, 1981 ALH swapped rabbit pickup, 1998 beetle
Ok, I think this is a TERRIFIC mod. So terrific I did it once in my stock cluster, and then again in my MFA sport cluster. The first time I did it myself. It was fun. The second time I had Ian do it for me. Even more fun!
 

EECSentric

Veteran Member
Joined
Mar 21, 2004
Location
Arlington, MA
TDI
2015 GSW TDI SEL DSG LP
Well, I let this go too long without replying. Sorry about that. Ok so here is everything in one post.

Vroom,

Very cool little board. I like the layout from what I can see of it.

ShokWaveRider,

Potentiometers can drift, especially poor ones. The biggest problem I forsee is actually getting better than 1% settability and so this drives the demand for precision multi-turn potentiometers. But this isn't really a big deal as 12-turn 200k pots run about $1 in single unit quantities. If desired, once set properly, a drop of epoxy on the lead screw will lock the thing pretty well.

As far as the brightness, yes, if the REFOUT pin on the LM391x is used to bias the comparator ladder and to adjust brightness, one will most certainly affect the other due to non-zero output resistance. But in my design, I've used an external LED to generate a stable voltage reference that drives the comparator ladder and this way REFOUT can be used to control brighness without affecting linearity. Furthermore, the LED could be replaced with an actual compensated voltage reference IC, but I foresee no real issues there. (BTW, the LED won't really light up all that much off a 3mA current)

CoolWht,

Absolutely, Ian's work is absolutely top-notch. I would have no reservations having him do the work. But it doesn't have the project value. I have this problem of making all tasks as difficult as I can, even when it isn't necessary. Hmm, yea, that's me.

BrentB,

It would definitely be cool to have all those other signals measured. The LM3914 does pretty well for such a simple linear signal from the boost gauge I would imagine, but for temperature and other things a more complex signal processing would be needed (assuming a standard double log thermistor). In reality, I think that it makes a lot of sense to go the MCU (microcontroller unit) route and ADC the signals.

The design that I am going with includes a decaying peak indicator, which somewhat increases the complexity, but I think for a turbo gauge it would be very useful. But then again, it begs for digital rather than analog processing. Why analog, well, I think really just for coolness. Who wants to really design an ADC to a MCU and then do all the processing in software for coolness?

The big project that I am trying to work on is an integrated car-computer. When I did the 5-light brake mod tonight, I pulled the CD-changer mounting bracket so I can modify it to accept a Mini-ITX motherboard. When I get around to putting the whole thing in I'll build/buy (depending on cost) a multi-input ADC board so I can feed these other non-time critical signals in [oil pressure, exhaust temperature, intake temperature, etc.] to the computer and have virtual graphs displayed on the screen in real time, along with logging.

Of course, I am trying to design a DC-DC power supply for the computer too, but that is much more complex than this little meter.

I think the secondary sensor will give a more reliable and calibratable signal, but Tech4TDI has a good graph of voltage vs. pressure for the OEM MAP sensor. I'll probably start out using this as well, but arrow.com has the MPX5700GP for $15US.

I definitely like SMT over through hole. Very cool and thank you about the CNC.

Oldpoopie,

Yea, I can't wait to see how this turns out. All my prototype parts are ordered so I can breadboard this thing.

Everyone,

So I did some redesign taking into consideration a lot of the advice you have all suggested as well as some own personal decisions. I pulled off the top LM3914 making this a 20 output max instead of a 30 output max. I also switched over to all surface mount components to shrink the size down since at this point, I figure not many people will actually want to build this on their own.

I updated the PDF on my site to include the revisions of both the circuit and the board, as well as a pretty complete description of the operation. The schematic includes most of the formulas solved for determining the correct calibrations given any desired input and output swing and or offset. As stated earlier, you could use this peak/average reading graph to read any linear analog input between 0 and 10v without any change in components.


Anyway, I'll keep everyone posted. Thank you all for all your help
 

ShokWaveRider

Vendor
Joined
Apr 17, 2003
Location
St. Augustine, Florida
IMHO You should stick to DIPs not SMTs, I think it limits the scope of the average hobby constructor. Use 2 PCBs for size if it is an issue and stack them. Also leave the 30 led option on the schematic as before, even if the PCB only caters for 20, Put an option box round it in the schematic, or publish a second diagram, as a lot of people would like 25 segments.

Just my Opinion.

Ian
 

ShokWaveRider

Vendor
Joined
Apr 17, 2003
Location
St. Augustine, Florida
For all those who like this project. I will be more than happy to Drill your dials, and mount and bond the LEDS (the hard part, as you only have 1 dial) in the colors of your choice and return them to you for for wiring. I have Red, Green, Blue, Yellow and Amber LEDS available. I have About 250 of each left and 400 Blues.

For the Canadians I can still do the complete installation if desired until October 2004 when I will be returning to the Caribbean for a few months again.

I can also sell you my complete Kit for you to install if you like. (Calibrated Board, LEDS, Sensor, Wire etc.) However, I will not be doing complete installations for the USA, as Canada Customs are not very accomodating for shipping clusters accross the border. But Dials are OK.

Just an offer,

Ian
 

Hoffer

Veteran Member
Joined
Mar 3, 2003
Location
Pittsburgh, PA
TDI
Golf GLS, 2003, Black
EECSentric:

I've got a Metcal at work, and I do have to do my own soldering at this company. We're mostly software, so when we started building custom hardware, all the fun stuff is left to us hardware guys. I'd be interested in one with SMT, as I personally could handle it. I suppose 20 output is fine, as opposed to a 30 output. Would definitely make mounting easier.

ShokWaveRider:

How much just for a drilling? I'd probably buy a bunch of LEDs from you as well, but I can do all the bonding, etc., myself. I don't have anything, nor do I trust my nerves enough to drill a $500 tachometer face. Plus, you've got the templates, experience, etc.

- hoffer
 
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