Ublox module , help needed! - Page 5

nl4jy · 06-03-2005, 03:57 PM

Guess it's time to blow the dust off of my SBR-LS.

Do you have a closeup view of the circuit board? I'm not good in EE and I'll need good pictures to hook my stuff up.

Laidback · 06-03-2005, 04:38 PM

Hmmm, first test in car wasn't so good! I connected the VSS wire but not the forward/reverse wire. The GPS bit works fine but nothing happened when I lost sat signal. I don't think it needs the forward/reverse wire as it didn't move backwards either.
See connection number 9 in Image3 below, what exactly does internal 'pull-up' mean?

Laidback · 06-03-2005, 05:17 PM

Ooops, just noticed that the gyro needs a 5v & ground feed itself and doesn't just take them from the Ublox module!

That could make a difference as the document states that 'if rate and speed are not connected then it will think the vehicle is standing still', rate is connected but without the 5v feed, it may as well be disconnected? that makes sense I think

RoyN · 06-03-2005, 05:55 PM

Hei Laidback, I see the SBR from ublox, and the antenna from ublox, but what is your supplier for the Murata? (This is the gyro I spose?) do you know an american supplier?

Thanks!

Laidback · 06-03-2005, 06:07 PM

Quote: Originally Posted by RoyN

Hei Laidback, I see the SBR from ublox, and the antenna from ublox, but what is your supplier for the Murata? (This is the gyro I spose?) do you know an american supplier?

Thanks!

Ublox supply it, go to the online shop and you'll see it. Not sure why it's not on their main site!

Laidback · 06-04-2005, 03:18 PM

Todays test better! Drove a quick circuit which includes a long tunnel, sat count went down to zero but the Ublox kept me moving along the map.When I got back I unplugged the GPS antenna and then drove around the block, again not a problem, I was placed exactly on the map.

So, looking good so far.

To do:

1, Run the VSS extension to the back of the car permanently.
2, Connect the forward/reverse wire (probably using the reverse lights somehow)
3, Add back-up battery to daughterboard. I'm not sure which type would be best, rechargeable, max 3.6v, something like the one in the USB GPS units? Anyone one point me to any links or has any ideas which type would suit best?
4, Box everything up, maybe with it's own 12 > 5v psu so it doesn't rely on the computer.

Alanh · 06-04-2005, 10:47 PM

Good to read of positive test results. I've got the Ublox GPS, antenna, and the gyro waiting for some time to finish my own setup.

nl4jy · 06-06-2005, 10:57 AM

LOL, any chance of selling the circuit boards for us lazy people? If the price if right, I think some of us would rather buy it than do it ourselves...

Maximus · 06-06-2005, 04:48 PM

Is the odometer pulses and forward/reverse signals 12V ?
Any specification on the speedo pulses ?

/M

Laidback · 06-07-2005, 03:14 AM

Quote: Originally Posted by Maximus

Is the odometer pulses and forward/reverse signals 12V ?
Any specification on the speedo pulses ?

/M

The odometer pulses, when stopped it is +5v, when moving it pulses to 0v. I don't know what the spec is but the module auto-calibrates itself against a good GPS signal. Same with the gyro.

Forward is high, backward is low. With nothing connected it thinks it's going forward, so I think for reverse, we have to pull it down to zero somehow.

RoyN · 06-07-2005, 06:53 AM

If nothing=forward, wouldnt reverse be something like -3v or -5v?

jcdillin · 06-07-2005, 07:27 AM

No, it's logic, so if you put 5v to the line then it's high, if you pull the line to ground then it's low. So if the line normally floats high, then for reverse all you need to do is get a switch and switch that line to ground when the reverse gear is activated.

RoyN · 06-07-2005, 08:35 AM

Yes of course.... the module is more intelligent than I am!

jcdillin · 06-07-2005, 06:09 PM

RoyN · 06-07-2005, 07:57 PM

Hey, thats not nice!

Hey Laidback, are you using this in your car fulltime now?