Custom USB tyre pressure monitoring interface

**Robby BMW** · 08-07-2008, 02:29 PM

Originally Posted by WuNgUn

Just having it plugged into the USB port...
I haven't tried running it yet (still on the bench)

Then is not a buffer problem, if the sortware is not running, there is no data exchange between the TPMS and the PC.
It sounds most like an IRQ conflict between the USB and the soundcard.

**Lok** · 08-07-2008, 05:03 PM

Sorry for not searching Robby

. It looks like I may have a sensor problem because I used the RR config utility with no luck. Tommorrow I am going to have the sensors checked and also I am going to take a couple of additional tires (regular not low profile) and have sensors mounted for testing. If there is a problem after that I guess I'll need to have a look at the reciever board... I am still using the 3rd eye hacked with the solder-on daughter board.

**bes51659** · 08-07-2008, 05:10 PM

Originally Posted by DigitalVampire

Do you have detailed snapshots of the sensor board...I'm curious to know the transmitter chipset.

The chips, apart from what I think is the sensor itself, is inside that white stuff. Probably to make it more dureable for vibrations. No way to detect whats inside. But I get the feeling it is discrete and not a chip(!)

Originally Posted by Robby BMW

No, the problem was due to a bug in the management of the USB input buffer.

Maybe you have confused the program flash memory, that require a second voltage supply to be programmed with the internal EEPROM, that can be written and erased directly by the program.

As I said I have not read the spec of the pic. But I am glad that it was a PC sw issue and not a PIC sw issue :-)

Looking forward to try it out this weekend!

**WuNgUn** · 08-08-2008, 12:02 AM

Originally Posted by Robby BMW

Then is not a buffer problem, if the sortware is not running, there is no data exchange between the TPMS and the PC.
It sounds most like an IRQ conflict between the USB and the soundcard.

Now why didn't I think of that? Even though it does this regardless of which USB port I use...
Maybe turning off IRQ assignment for all onboard USB ports? Or manually assigning them (if the hardware shows up in the BIOS that is).

Thanks for the tip...I'll look into it.

**Enforcer** · 08-08-2008, 12:09 AM

Originally Posted by bes51659

I have just installed the 3'd eye sensors on my wheels.

[media]http://web.comhem.se/mulle4/tpms_sensor.jpg[/media]

Quality is not impressive. I manage to destroy one sensor.

[media]http://web.comhem.se/mulle4/brokensensor.jpg[/media]

The instruction manual was not specific on how to place washers. I did not use my sense, and placed alu washer on wrong side first as I tried to do it as I could see from picture in manual. Alu washer goes on the outside...

The aluminium nuts also loose shape once fitted, and it is a bit difficult to refit the tyres. At least the low profile 18" I've got on my E46 BMW.

The washer for the insex nut at the sensor also gets deform once mounted.

The pin for holding the pin still when fastening the nut did not fit 3 of the 5 sensors I tried.

In short, you get one chance to do it right and you cannot refit a sensor once used.

I think we have already discussed this and decided that you don't need to use the valves supplied with the system. The actual sensor is the black bit and as long as it is secure in the wheel/tyre it will work.

Anchoring it to the valve is just a convinient way of securing it.

**bes51659** · 08-08-2008, 03:03 AM

Originally Posted by Enforcer

I think we have already discussed this and decided that you don't need to use the valves supplied with the system. The actual sensor is the black bit and as long as it is secure in the wheel/tyre it will work.

Anchoring it to the valve is just a convinient way of securing it.

Sorry if I missed that (and other things) given that the thread is now 48 pages (!)

Anyone tried a different assembly? For the balanceing of the wheel to work it has to stay put. Epoxy?

**Enforcer** · 08-08-2008, 08:59 AM

Originally Posted by bes51659

Sorry if I missed that (and other things) given that the thread is now 48 pages (!)

48 pages, puh! that is nothing you should see some of the skin and plugin threads.

O, and it might have been in a different thread about the TPMS so don't beat yourself up about it

**WuNgUn** · 08-08-2008, 09:14 AM

Originally Posted by bes51659

Sorry if I missed that (and other things) given that the thread is now 48 pages (!)

Anyone tried a different assembly? For the balanceing of the wheel to work it has to stay put. Epoxy?

I would think good quality, double-side tape would work...just put it on a horizontal surface. That way, with the wheel spinning, centrifigal force will 'push' it harder in place.

On that note, I find the valves that come with the kit to be different somehow. I've gone to two service stations for air, and both time the air just leaks out past the nozzle instead of going into the tire!
I gotta find somewhere to get air!

**Lok** · 08-08-2008, 09:41 AM

When I go to the tire shop in a bit I will see if I can get the sensors mounted with tape to rim instead of messing around with the valve stem. I have some really nice industrial grade high temp stuff that should work.