Samples have arrived.



The smaller oled display looks very tiny to me. IMO any meaningful information wouldn't be easily visible from anywhere other than dash area.

I think the oval box looks excellent, but is possibly a bit small to fit the electronics without going surface mount. It would also mean bringing a connector out of the back making flat mounting difficult, and TBH it would be hard to mount any way other than velcro pad on the back as there isn't a square face on the damn thing


Thoughts folks ?

My thoughts - if it was for me it would be in the din case in the centre console or the flat rectangular box velcro'd to the dash with a nice big display - but then I'm not a fan of form over function.

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If at first you don't suck seed, try drier grain.

I'm just spitballing here

How about start out on the big din box with plenty of room for prototyping. Then consider an umbilical option for a remote display at a later date. This would, of course, be dependent on being able to extend the display connector somehow
That way you get a nice easy prototype with the possibility of an astheticly pleasing end product. It also gives you a box suitable for attaching many sensors to - something that would be tricky with the sexy super slim boxes

Velcro'd to the sun visor looks a possibility for the square box but I get no feel for the depth of it from your photo

I hope the displays come with a user manual. I read the datasheet on RS for the little one and am none the wiser on how you drive it

The displays come with nothing but a nice plastic box. Par for the course. I expect I can dig some data from somewhere. I'm also not that happy with connection method via fine pitch flexible PCB, I'll put money on the connectors only being available in surface mount. I'll have another look at that rapid one, I seem to remember it had pins and it said it was available in colour.

I was considering the big box to hide plus link to a display via canbus, but I think I can fit it all in the flat rectangular box on 2 PCB's piggybacked. The dowside would be a single multipin connector (large) sticking out of side or bottom and a multicore cable down behind the dash to split to the various places. This will spoil the looks in it's own right.

The large box would give more flexibilty for splitting the connectors so the ones normally splicing from dash can go on one connector with a breakout loom supplied, extra inputs on a separate connector that's easy to wire to, canbus & RS232 on their own connectors.

The separate display via canbus (4 core only needed) could then be a standalone product for those with OBD2.

I don't particularly want to go for a prototype only phase. It's a pretty simple job so would prefer to go straight for production format and iron out the minor bugs in the first small batch.

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If at first you don't suck seed, try drier grain.

Big din box with display would be my choice for development work as it makes wiring looms more sensible. Bung a SD card reader in there for logging
Then for discreet installs drop the big box display and add a sexy slim case display. This harks back to my original idea of a sensor-> obd2 box which can then work with any external gauges of your choice
Would it be possible to design the display in the big box such that it could be dropped into the smaller box with perhaps just an additional can interface? You'd end up with a few products from a single base product then

I know Don had niggles with wiring on his AIM display. It wasn't a problem but the requirement for an arm sized sensor loom didn't make fitting it any easier

I'm starting to think along these lines. I can do a display board on the same artwork & just have on set of tooling cost / minimum order and aim to sell the bulk as pairs. Overall cost of full system will be slightly higher but probably not massively so.

This may come back to having a humungus easy to read alphanumeric display for the centre console (cheap so no worry about leaving it on there anyway) plus a nice display in a slim case via a thin 4 core cable and maybe small plug at the display end, or just flying lead with plug at big box end.

The other upside is the small display would also work direct from my ECU too.

For comparison, the big alphanumeric display I was originally thinking of. It can be read at a glance from anywhere in the car, and probably the following car too

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If at first you don't suck seed, try drier grain.

I like the big display but I also don't want to be blinded in the dark

I mentioned my display at the curry meet which is designed to work with DTA ECU by a DIY type guy on the DTA forum.

viewtopic.php?f=9&t=2419&hilit=arsey&start=24

Apart from the size/shape and display the functionality I think is pretty much spot on. IIRC these were around £225-£250 with a little bit of profit for the designer/builder.

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JP
GT4DC Treasurer

Grey St185 RC
Silver BMW E46 M3
Multicolour yawn Honda VFR400
Silver Honda Civic Type-R

Looks a fairly well thought out piece of kit JP.

Looks wise, IMO it would better off without the leds (you can do the bargraph on the display, and 8 leds isn't enough to be meaningful) and a proper printed membrane instead of a bit of carbon effect sticky back plastic. Also, use buttons built in the membrane rather than switches sticking out of the plastic. Otherwise, a professional build quality on the electronics.

I think the text would be too small for me unless it was a huge display. My preferance would be 2 or 3 bargraphs at a time (selectable) with the label and value in text in the bar (invert the colour of the bar with the text so the bar can pass through the text).

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If at first you don't suck seed, try drier grain.

Direct question for Don, Malcolm or anyone else who does circuit racing / serious track stuff regarding the data logging side.

For lap times / split times what is the modern way to sense crossing the line. Back when I was last involved (near 20 years ago) it was infra-red beam but this was largely for practice only. Is it now RF transponder, and is it standardised and provided by the track now ? There was talk of doing this when I left the scene.

For transfer of information from device to laptop, would you prefer / expect to plug in a laptop to it, or would it be better to store on a SD card / usb stick ? I can see sense in the latter as you can keep a card for each session and no need to download in between.

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If at first you don't suck seed, try drier grain.

I agree on all counts CDB although the LEDs used as shift lights primarily with all flashing in event of a fault/over spec input they shoul be quite handy.

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JP
GT4DC Treasurer

Grey St185 RC
Silver BMW E46 M3
Multicolour yawn Honda VFR400
Silver Honda Civic Type-R

Struggling to find a suitable connector for the displays I've looked at so far. Going a bit bigger yields one suitable for through hole connection. I'd be happier with a bigger display as the ones I've looked at so far are a bit smaller than I'd like.

http://uk.rs-online.com/web/p/lcd-colou ... s/7502572/
3.5 inch screen. 72mm x 52mm active area

And a bigger flat box. Not massively bigger than the previous rectangular one. 155 x 96 x 20

http://uk.rs-online.com/web/p/hand-held ... s/5095261/



Would this be getting too big do you think ?

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If at first you don't suck seed, try drier grain.

I know the question wasn't aimed at me but most datalogging systems for laptimes are either transponder, GPS or both.

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GT4DC Events Co-ordinator
1996 ST205 UK

My Formula Ford has both a transponder and an infra red timing beam sensor. Only the IR sensor is connected to the Pi dash/datalogger. The transponder is mandatory now and most people buy and fit their own although I believe you can also hire them for the day. This is used by MST timing to produce the official times for the event. TSL also provide a similar service. For some events they live stream the times to their web site. This has recently been extended to video coverage including on-board although I've found the quality a bit variable. MST and TSL publish all the timing on a PDF on their web site after the event.

With my Pi system and also my old M4 Pro MoTeC the only way to pull the logs was by connecting a laptop via RS232/USB. The RaceTechnology mandatory dataloggers used in the BTCC use SD cards as this is much easier for the scrutineers to collect in the post race parc ferme. I think this facility is really useful although you still need the laptop for configuring the systems such as ECU, PDM and Dash.

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Don
GT4DC Chairman
1994 Toyota Celica GT-Four ST205WRC JDM 269bhp @ 0.9bar
1994 Toyota Celica GT-Four Special GT 590bhp @ 1.8bar
1989 Van Diemen RF88/89 Formula Ford 1600
2008 Nissan Patrol GU 3.0L ZD30DDTi 154bhp

Just to expand on Mike's reference to GPS. This is mainly used for track mapping as its more accurate than the datalogger accelerometer for creating track maps. GPS can be used for 'lap times' but this is mainly for recreational use e.g. track days. I don't think the accuracy is good enough for race timing which is to thousandths of a second.

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Don
GT4DC Chairman
1994 Toyota Celica GT-Four ST205WRC JDM 269bhp @ 0.9bar
1994 Toyota Celica GT-Four Special GT 590bhp @ 1.8bar
1989 Van Diemen RF88/89 Formula Ford 1600
2008 Nissan Patrol GU 3.0L ZD30DDTi 154bhp

Chris, seems like a groundswell of opinion for a DIN size box which could slot into the centre console. I like the concept of being able to drive a smaller display through an umbilical. In my situation I don't particularly want to remove the Defi DIN display so I could mount the main box out of sight and drive the small display through the umbilical.

Steve made the point about the sensor cabling. This cost me a small fortune and was quite challenging to route the sensor cables neatly into the back of the AIM MXL display. Food for thought.

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Don
GT4DC Chairman
1994 Toyota Celica GT-Four ST205WRC JDM 269bhp @ 0.9bar
1994 Toyota Celica GT-Four Special GT 590bhp @ 1.8bar
1989 Van Diemen RF88/89 Formula Ford 1600
2008 Nissan Patrol GU 3.0L ZD30DDTi 154bhp

Don't despair Don.
Chris and I spent quite some time on this. I'll let Chris divulge where we got to as it's his baby