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Speedometer visibility issues

Discussion in 'Roadster: Technical' started by Laurent, Aug 25, 2008.

  1. Laurent

    Laurent Member

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    I've taken the Roadster for a test drive 3 times now, and every time I have trouble reading the speedometer. I try not to go over the speed limit (by too much :biggrin:) but it's hard when you can't easily tell how fast you're going. In my Prius, there's a very handy digital display (see picture below) but in the Roadster I can't tell quickly if I'm going 62 or 68mph. Can the display below the tachometer be used to show the speed ?

    Prius dashboard:
    2423836077_3f57e65e20.jpg

    Roadster dashboard:
    2796383645_df8be2e94b.jpg
     
  2. TEG

    TEG TMC Moderator

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    Your Tesla pic seems to be of the old "EP" design. Didn't you have the newer white on black dashboard?
    2697394899_193ca1ab14.jpg



    If all else fails, you could try an aftermarket add-on like this:

    Odyssey Series I, Mini Speedometer
    prd_sm_296.jpg
     
  3. vfx

    vfx Well-Known Member

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  4. Sparrow

    Sparrow S105/ Roadster 189

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    In my 1.5 Roadster with the JVC navigation unit, it has a nice screen that shows speed, 12 volt info and the clock. I hate the navigation part of the unit, but I always put the JVC unit into the speedometer mode so I can more clearly see what speed I am going. I'm use to some Toyota vehciles that have the speedometer in the center of the dash so it isn't a big change for me.
     
  5. NigelM

    NigelM Recovering Member

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    Isn't that speedometer a GPS based one, rather than actual road speed? The only problem with it is that there may be a time delay versus your real speed.
     
  6. Sparrow

    Sparrow S105/ Roadster 189

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    Yes, I'm assuming it is a GPS based one, but it seems to match pretty well with the actual speedometer (+ or - 2mph) when I compare them and there doesn't appear to be any practical delay in the readings it gives.
     
  7. markwj

    markwj Moderator, Asia Pacific

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    The double-din units have a similar display, and I use it all the time. But, 3 issues:

    1. It is not in the drivers direct line of sight - eyes off the road.
    2. It is slow to reflect changes in speed.
    3. Lots of tunnels and underpasses where I live means the display is frequently wrong.

    You might notice in the picture I also have a GPS-based radar detector up by the windshield. #1 is better for, that, but it still suffers from the other 2 issues.
     
  8. markwj

    markwj Moderator, Asia Pacific

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    Not sure if this is on-topic, but has anyone tried one of those little ODBII bus displays that can show customizable widgets (such as speed)? I've been holding back because I'm hoping to put a Tattler in my ODBII port.
     
  9. dsm363

    dsm363 Roadster + Sig Model S

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    They could simply replace the face of the odometer display and extend the lines to the center of the needle (with speed markings). That would be cheap and wouldn't require a firmware update.
     
  10. scott451

    scott451 KWH-PWR#1349Sprt,S Sig#96

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    Actually the JVC uses the speed pulses sent from the roadster to calculate the MPH. Initially, When the JVC is installed there is a cal proceedure that maps GPS speed to speed pulses. After that cal, it only uses the speed pulses. The GPS is too slow for MPH updates.

    ODBII (driver side) won't work for two reasons: 1) No OBDII CAN messages on the port 2) OBDII baud rate on the roadster is 1Mbit, most tools expect 500K or less. The tattler uses the debug port on the passenger side.

    Yes. I have successfuly overridden the LCD display. I replaced "trip" value on the LCD with mph since trip is also available via the VDS. The LCD still shows "29.5 mi Trip", but "29.5" is actually the current MPH. I don't know if the CAN controller on the tattler is fast enough to make it work without the LCD flickering. but it is on my todo list...


    Now that I've switched from a 1.5 to a 2.5 it's much harder to see the speedometer. On the 1.5 the speedo is on the right so 55-75 is kind of near the center of the binicle. So I could slump down and see the speed. On the 2.5, the speedo is on the left and I can't see it at all.
     
  11. TEG

    TEG TMC Moderator

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    I have a really old Garmin unit that shows (fairly accurate) MPH even though it doesn't connect to the car for anything other than power. So, at least some GPS can do MPH from the sat signal. I think that Garmin has a fairly slow processor too. On the other hand, the Roadster can change MPH more quickly than any of the cars I had my own GPS in...:wink:
     
  12. vfx

    vfx Well-Known Member

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    My Magellan GPS is so slow that I can't even count on it to update streets quickly enough. Forces me to slow down sometimes.
     
  13. NigelM

    NigelM Recovering Member

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    They all can (unless you have an antique one). Most boats rely on GPS for speed indication as the thru-hull speed wheels get clogged up with seagrass and/or barnacles on a regular basis. LE on the water rarely gives speeding tickets unless you are blatantly racing through a no-wake zone.
     
  14. Doug_G

    Doug_G Lead Moderator

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    My relatively new Garmin has a reasonably fast update rate, but it's still slower than the VDS. But what it displays agrees very well with the VDS.

    (One caveat - the Garmin doesn't work worth beans in downtown Toronto; must be multipath from all the tall buildings. Strangely enough the crappy JVC's GPS, which sometimes indicates that my garage is in a local river, has no trouble at all with that!)
     
  15. TEG

    TEG TMC Moderator

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    My old Garmin also has my location jumping off into random places when I drive between tall buildings.
    I think the car integrated GPSes tend to avoid this because they use car speed sensors (and maybe even steering angle sensors) to know when to ignore GPS readings and internally conclude "this must be multi-path as the car hasn't really suddenly driven over there."

    The best car integrated GPS systems seem to consider and correlate multiple sources of input to make a "best guess" as to your actual location, speed, etc.
    Also helpful and welcome as you drive through tunnels.
     
  16. felixtb

    felixtb RsEU502,Sp+14274,XpEUSig4

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    for the roadster though, it is not integrated that way since it is not an OEM part. however, the separate antenna in any in-car system including the one in the roadster is much stronger than the integrated antennas in portable systems such as the garmin
     
  17. S-2000 Roadster

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    #17 S-2000 Roadster, Aug 4, 2011
    Last edited: Aug 9, 2011
    Same here. My decade-old Garmin GPS III+ served as my speedo after my CRX Si was stolen and the instrument cluster was taken - the car was recovered. It's slow, but not any slower than my dad's Ford Thunderbird with digital dash. I spent about 5 years using the GPS for speed and odometer (with no fuel gauge, I had to be really familiar with the car's average mpg). I did finally find an instrument cluster on eBay, and it's surprisingly reassuring to see a needle smoothly flow from speed to speed.
     
  18. mpt

    mpt Electrics are back

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    The JVC does get a speed signal from the car so goes into dead-reconing mode when it looses the gps signal, which isn't often as it has an external GPS receiver. I'm not sure where it is though. It might be in the same location as the garmin gps used by Tesla. That's located under and ahead of the left-hand headlamp.

    Sorry, please resume normal topic...
     
  19. doug

    doug Administrator / Head Moderator

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    pics?
     
  20. dsm363

    dsm363 Roadster + Sig Model S

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    William3: Can you post the exact part number you bought as well? Thanks.
     

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