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PostPosted: Tue Jan 22, 2013 1:17 pm 
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Following a discussion at the curry meet recently, I'm looking at the feasability of developing a digital dash as a replacement for the standard instrument cluster.

The prime advantage as I see it is that it will monitor the engine sensors and provide a warning if anything goes wrong. The saves the driver from constantly monitoring gauges, or more likely it will wake the driver from autopilot as soon as something starts going wrong rather than when the engine starts coughing and spluttering making the driver look down to see what's just caused the destruction. It will also be able to take additional sensors to provide extra warnings. e.g. we can fit a wideband sensor and program it to warn us if it goes weak on boost.

Proposed spec:

Mechanical:
it will srew on the back of the existing trim in place of the standard circuit board / dial background.
One colour graphic LCD display (probably widescreen) as big as will fit. Maybe one or 2 small displays filling in the wasted space for extra info display, possibly large size text only.
Trim front over the display(s) to make it look good, possibly supplied by Mook.
It will have OEM connectors so will be direct plug & play on all existing sensors.
Extra connector or 2 for additional sensors.
Extra connector(s) for canbus / obd2 / usb to link to PC for configuration / logging.
There will be versions available for each car covered (probably be gen 6 & gen 7, depending on interest)

Functional spec.
Graphical dials on the main screen for speed / tacho, plus inset text for accurate readout. Poosibly one or 2 extra small dials for other display, e.g. temperature, boost, fuel. (user configurable setup so all required information is dispayed).
Text display on the small screens for less critical information / and or alarm / warning / error display.
The system will monitor all inputs against configurable limits and provide an alarm if something goes out of limits, this will include the ability to gate several inputs together to avoid false alarms (e.g. ignore low voltage below 1500 RPM)
Several levels of alarm selectable (from non urgent which will just be a text alart, to critical (e.g. low oil pressure) which can provide audible alert and flash the screen.
Relay output for critical alarm which can be used to cut ignition or just for a big dash top lamp.
Display will automatically switch to show an input in 'alarm state' so the driver can monitor it.
May include a G sensor to allow horsepower calculation.

It may include a logging facility, maybe storing just alarm information, maybe allow storage of full logging data for short periods for download to a laptop.

Price.
Finger in air, probably looking at £300 - £500 (likely upper end of this range)


What are peoples thoughts ? Any ideas for extra functions ? which functions would be of interest to you ?

I know there are other 'off-the-shelf' systems out there for digital dashes, but I'm not aware of anything that's plug & play to exactly fit in place of the standard dials and look like it's meant to be there.

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PostPosted: Tue Jan 22, 2013 2:21 pm 
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love this idea and would be inline to get one by the sounds of it youve coverd the basis just wounderd if you would do custom build ie oil pressure turbo boost psi just a few ideas

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PostPosted: Tue Jan 22, 2013 2:46 pm 
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It will allow extra sensors to be connected with standard 0-5V output (+ maybe a few resistance measuring ones) and then all configuration in software via the PC connection and a piece of downloadable software.

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PostPosted: Tue Jan 22, 2013 3:01 pm 
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As a business proposal I don't think it works. The market is too limited if you're going to make it application specific. If, as with the ECU, it's something you want that might bring in a few quid then the idea is sound enough.

The concept is fine and indeed major manufacturers are adopting this approach integrating all manner of infotainment functionality as well. Take a look at the new BMW f20 dash cluster - the lower half is all LCD, the GTR centre display of all kinds of figures, etc etc

I have looked into this for the red car - it's already running a PC system so would only require a suitable display setup.
IMO the display needs to be dot matrix to make it flexible and high readability LCDs don't come cheap, especially if you look at el or amoled translflective screens in low volume. Obviously they can be procured at good prices if you look at the current crop of mobile phones with huge hi-res displays but low quantity = high price. Fixed "segment" type displays are cheapish but initial tooling costs are high

I personally would look at a different approach.
A lowish cost data logger with multiple inputs that can output realtime over CAN. End users are then free to hook it up to something like torque running on phone/tablet to get whatever display they like. It should work out cheaper and it's infinitely more flexible in end use - a Nexus 7 tablet is 200, torque and obd Bluetooth adapter is about 30 leaving say 100 for your adapter box which doesn't need to be much ,ore than a PIC with sdcard adapter

OK you do lose out on custom fitment but I think that is what most limits the product. You also evade some of the potential legal hiccups like ODO functionality as the OEM dash can stay in place

The likes of PLX gauges would also be directly compatible opening up even more opportunity to sell your logger/interface box not to mention competition applications where people just want logging


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PostPosted: Tue Jan 22, 2013 3:14 pm 
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Looking at something like this initially for a display.
http://uk.rs-online.com/web/p/lcd-colou ... s/7502588/

Are there any specific laws on odometer ? bearing in mind people can swap dashes between cars or disconnect the speed sensor, isn't the onus on the owner to maintain / declare the correct milage ?

I'm guessing what you're suggesting Steve is a box with inputs which can connect to sensors (or splice into dash / ecu) and provide OBD2 output for older cars which don't otherwise provide obd2 ? A bit more difficult technically as you're at the mercy of the standard gauges and what they're pushing out to the sensors (e.g. driving voltage & resistance to measure the ECT thermistor).

The main celica market for the dash I suspect is likely to be the Gen 7 boys (they already have OBD2)

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PostPosted: Tue Jan 22, 2013 3:34 pm 
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An interface box is a pretty accurate name

Heck I'd be tempted to buy a couple of boxes if I could throw my tablet in two cars and get a fullish dash display.
Stick a serial port on it and I could imagine quite a few MoTeC M4 users cuei...queueuein....knocking on the door. That's the beauty when these days a huge number have 50% of the solution already in their pocket. I bought an obd-> Bluetooth dongle for the bimmer (which unbelievably doesn't have a temperature gauge) but I wouldn't even consider a dash display in that situation. The beauty of this it that for a couple of hundred more I could use the same setup across all my cats - something of a no brainer for me and I suspect many people would be in a similar situation - older fun car and something reliable for work :lol:

Retaining a stock dash does also remove some extra hurdles like hooking into all the existing dash connectors - indicators, fog, fuel etc etc which cuts down on some cabling and complexity
You do still have to interpret existing engine sensors (which your dash would need to do) or provide additional external sensors of your choice. You could howeve sell it pure configured for say a gt4 with a ready made ECU breakout loom and pure configured calibration tables. This would make it PNP

Its an idea I've given a reasonable amount of thought to as I think it's a commercially viable product and it is something that would be useful to me


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PostPosted: Tue Jan 22, 2013 3:41 pm 
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Re the RS display
I don't think it would be sufficient
Here's the problem. A dash replacement means the dash must be readable under direct sunlight or you don't have a speed indicator. A lowish contrast reflective LCD won't work then. Plus it absolutely needs extended operating temp capability. My greedy LCD goes black in summer until the cabin cools. Not a problem but if that were my only speed/fuel etc display it would be a big problem

ODO is one I'm not absolutely sure on. It is a requirement that one be fitted (and technically I believe an not fail if not present, just like the speedo which is never actually tested) but I don't know whjo is responsible for accuracy


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PostPosted: Tue Jan 22, 2013 3:46 pm 
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ECU signals would provide -

RPM
Speed
Engine temp.
Intake temp (x2)
Boost
Knock.

Not much else you'd want to look at.

Dash info would provide:

Speed
RPM
Engine Temp.
Boost
Fuel level (pretty important to display on a dash & I'd want an alarm on it)
Oil pressure warning (vital to go into a warning system IMO)
Oil level warning (if available) (useful to go into a warning system if available)

So I would be inclined to do a breakout loom to the dash rather than ECU for a box of tricks, maybe a breakout loom for ECU to pick up air temperatures and possibly knock.
For an integrated dash, maybe worth providing an optional breakout loom for ECU to spare inputs to pick up the above.

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PostPosted: Tue Jan 22, 2013 3:49 pm 
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After discussing this at the curry I'm really pleased that you've decided to give it more thought.

I think for something to work as an actual dash replacement then it would have to look 'really' good in terms of the quality of display and the fitment / surround that goes with it.

I personally think that something designed to be DIN sized (not necessarily the whole thing - just so the box fitted there) would be the ideal solution.

To me the critical aspects in terms of it being a useful driving tool are:

- Monitoring all the sensors that it is connected too.
- Configurable alarms on all sensors both high and low values
- The parameter that has caused the alarm to be displayed on the screen
- A driver to an external output so that the device can trigger a bright LED/loud buzzer etc

From all my research into the area (and I have done a lot) trying to find a solution for my car, I can report that there are many many options out there however they all fall down on one more more aspects.

There are very good systems that meet all my criteria but they are well over 1k. The cheaper systems appear on the face of things to be good value but then they typically all fail at one or other hurdles such as not displaying the alarmed parameter on the dash or requiring resets to look at different readings, through to the way in which alarms are interpreted and requiring specific and unusual sensors.

I think from the above you are proposing to use the standard sensors, my feeling is this might be a bit ambitious and there are several important areas that the standard setup doesn't monitor like EGT, Fuel Pressure, Oil Temperature and Oil Pressure. Given that plumbing most of these sensors in is not that difficult I would be more in favor of a display using additional sensors of a standard type (bosch temp sensors & wideband, k type thermocouples etc)

Just my thoughts. :)

In terms of legality etc - for dash replacement there is a product called Digidash which is very popular in the kitcar world which provides an all in one solution in terms of the statutory instrumentation and some extra sensors. I don't think it can do stuff like EGT and widebands but might be worth looking at for ideas if you want to go down the dash replacement route.

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PostPosted: Tue Jan 22, 2013 3:58 pm 
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The RS display was just the first one I looked at with a price tag that looks viable. It does say transmissive with LED backlight, not reflective ? Obviously I would test displays first anyway.
It's quite rare to get direct sunlight on the dials as they are normally fairly well burried & shrouded, and the driver is normally sitting in the area which would allow direct sunlight through the back window. I would still try to get one that's readable in this state.

As regards the temperature dependance, I would presume there is a contrast control which can be adjusted automatically from a thermistor mounted on the board.

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PostPosted: Tue Jan 22, 2013 4:15 pm 
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Sirius wrote:
After discussing this at the curry I'm really pleased that you've decided to give it more thought.

I think for something to work as an actual dash replacement then it would have to look 'really' good in terms of the quality of display and the fitment / surround that goes with it.


My thoughts too, and that was the plan. Research may deem this unfeasable at a sensible price, or maybe not.

Sirius wrote:
I personally think that something designed to be DIN sized (not necessarily the whole thing - just so the box fitted there) would be the ideal solution.

To me the critical aspects in terms of it being a useful driving tool are:

- Monitoring all the sensors that it is connected too.
- Configurable alarms on all sensors both high and low values
- The parameter that has caused the alarm to be displayed on the screen
- A driver to an external output so that the device can trigger a bright LED/loud buzzer etc

From all my research into the area (and I have done a lot) trying to find a solution for my car, I can report that there are many many options out there however they all fall down on one more more aspects.

There are very good systems that meet all my criteria but they are well over 1k. The cheaper systems appear on the face of things to be good value but then they typically all fail at one or other hurdles such as not displaying the alarmed parameter on the dash or requiring resets to look at different readings, through to the way in which alarms are interpreted and requiring specific and unusual sensors.

I think from the above you are proposing to use the standard sensors, my feeling is this might be a bit ambitious and there are several important areas that the standard setup doesn't monitor like EGT, Fuel Pressure, Oil Temperature and Oil Pressure. Given that plumbing most of these sensors in is not that difficult I would be more in favor of a display using additional sensors of a standard type (bosch temp sensors & wideband, k type thermocouples etc)

Just my thoughts. :)


You've just described the product I've had in my 185 for the last 5 years, apart from it isn't DIN sized. It's just special software in a standard procuct I manufacture for another application.

Maybe worth customising & re-packaging as you describe.

http://www.cdd.co.uk/monitor.htm
http://www.cdd.co.uk/gsm.htm
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http://www.javelinirrigation.co.uk/html ... onitor.htm

The main problem I have is that to make a custom plastic 'box' that looks good is unfeasable, tooling costs are £20K + and minimum quantities in the thousands. Anything made in 'off the shelf' boxes is likely to look amateur for this sort of application.
With a dash replacement, it would be easy to make a PCB the right shape & size to screw in the existing instrument cluster plasics, a sheet of perspex cut to shape & size mounted over the front carrying a Mook style 'sticker' with clear window for the display(s). This has potential to look first class.

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Last edited by Nibbles on Tue Jan 22, 2013 4:20 pm, edited 1 time in total.

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PostPosted: Tue Jan 22, 2013 4:19 pm 
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The blank display is a common LCD feature. I think it's just a function of the technology but it is a problem in a fixed auto environment when cabin temps can easily hit 70 even in sunny England

You are dead right that most of the time the dash is shrouded but there are odd times when it isn't and plenty of times when bits of it are exposed. It's not an issue for me, I have a hand with a shadow attached but it would be for some and as the only information display this does make it an issue

Display wise you need transflective or amoled or el to be sunloghht readable - the defi display which IMO is miles ahead of others looks to use high contrast EL
Transmissive, as per the RS on, relies on backlight power and will be washed out by sun unless you start looking to funky dispersion coatings. Yonks ago I was developing an application for naval use and they introduced a requirement for direct sunlight readability. At the time transflective or EL was the only technology that would stand up


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PostPosted: Tue Jan 22, 2013 4:23 pm 
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PS,
Previous generations of the display used custom LCDs which blanked during environmental testing. A waiver had to be negotiated that as long as it recovered in human tolerable conditions it was ok


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PostPosted: Tue Jan 22, 2013 4:36 pm 
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Do you have any sources for suitable displays ? Are they available at a price that would make this feasible ?

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PostPosted: Tue Jan 22, 2013 4:52 pm 
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Mike - presumably something like this with display & buttons on the front, connectors at the back ?

http://uk.rs-online.com/web/p/instrument-cases/0508677/


Finger in air, probably £250 - £300 ish with 2 line alphanumeric display (hopefully 10mm high digits)

These are the displays I'd suggest. They are much easier to see in all conditions than any graphic one I've come across. We use these on our electric vehicle coin mech. system as they don't fade out when cold and are easy to read even in direct sunlight.

http://uk.rs-online.com/web/p/lcd-monoc ... 4E4F4E4526

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