Custom USB tyre pressure monitoring interface - Page 14

mrbean_phillip · 12-17-2007, 10:44 PM

@ Digital Vampire: Yep, it should work pretty well, one just needs to make sure that the pressure sensors match the frequency of the receiver.

Another nice feature is that it can be interfaced (via MAX232 line driver) directly to your PC serial port, which is an alternative to Robbie's design - with one caveat - you will have to do the software application on your PC, where Robbie has his running in the PIC Micro....

Both have advantages though, this provides for an alternative

Enforcer · 12-18-2007, 08:28 AM

Quote: Originally Posted by DigitalVampire

Parallax 433Mhz Receiver is available for ~40$

Which equates to $120 for a full set. (richyrich might me able to get full kits for $100 + expenses)

Also they look pretty open to have dangling in a tyre.

LYHTSPD · 12-18-2007, 08:33 AM

Quote: Originally Posted by Enforcer

Which equates to $120 for a full set. (richyrich might me able to get full kits for $100 + expenses)

Also they look pretty open to have dangling in a tyre.

DigitalVampire posted a link to a reciever, not a sensor. You would still have to source your TPM sensors, but this way you would not have to buy a $250 product and end up not usuing 3/4 of it. If you could use the extra sensor set that you can get from 3rd Eye at $100 for 4, you might be able to get by with about $160 for a functioning TPMS system. I would love to see richrich get a hold of these at $100 a set, but that it going to take a lot of capital up front from him.

We wait and see...

dyne · 12-18-2007, 09:27 AM

Using the parallax receiver with a serial interface sounds like it would be great. There are a number of tpms sensors for well under $100. You would just have to find ones with the appropriate frequency, right?

almera · 12-18-2007, 01:53 PM

It wonder if it's possible to use that generic receiver for both TPMS sensors and wireless parking sensors at same time with a custom sw on PC

mrbean_phillip · 12-18-2007, 04:51 PM

@ Dyne and Almera: You are both correct, provided you can find transducers with the correct frequency, there is no reason why this will not work - think aboutb your FM radio back in the old days (for those old enough to know what a FM-radio is, lol) You tune your radio until you hit the frequency of a station you want to listen to.

Now, with these transducers, it almost works the same - except they transmit at a fixed frequency, and the receiver (radio, or Parallax Rx in this case) receives the signal, as it is "tuned" to receive exactly at the frequency the transducers (tyre press sensors) are transmitting on.

Provided each sensor has a unique ID, there is no reason why you cannot have 5 or 10 transducers, or heck, even 20, but decoding the data will be done in the software application, and there you have to cater for how many sensors you want to "read" or "scan"

Hope this makes the muddy water a little more clear.

LYHTSPD · 12-18-2007, 04:59 PM

Does anyone make a tuneable RF reciever? Can you make your own broad-range reciever and just match it with a filter that corresponds to the sensors?

DigitalVampire · 12-18-2007, 09:21 PM

Does anyone know the website of the manufacturer of Valet TPMS?
I tried google, but does not link to the manufacturer website

brandname2007 · 12-18-2007, 09:44 PM

I think the best development should be directed towards the new battery-less TPM sensors being developed by Transense and VisiTyre. Most of these systems have a circut board that ties in with the ECU, which could most likely be compromised by the vast variety of hardward gurus we have floating around here. From there, someone could write some I/O code for patching it via COM1 on a carpc.

mrbean_phillip · 12-18-2007, 10:45 PM

@ Brandname2007: I have been in contact with VisiTyre, and yes, their device would be far superior to anything else out there, as you can communicate to it via CAN bus, which would work great on my car, as I can use my J2534 tool to capture the data and display it directly to my carputer OBD-II software....but...there's a catch.

These units use special transducers that are imbedded into your vehicle's rims (wheels), with pick-up coils on the hubs, and then an electronic box hardwired to your system, either onto the CAN-bus or whatever interface is supported.

So, the real issue is that you will need to have these embedded into your rims, which is the difficult part, as according to the supplier it will be done at manufacturing time of the wheel.

So.....I guess it would be very possible, just a load of work to install these if diy, bu doable.

Let's see what happens

edit: Before I forget, there's a few (industrial) serial and usb CAN-modules available on the market (I have a serial Rockwell unit) that will connect directly to your PC's ports, so it can interface to the VisiTyre system...the application would have to reside completely on the PC though in this case if used as standalone....we have to find out if the VisiTyre system is CAN 11-, or 29-bit....

MGD · 12-28-2007, 11:14 AM

Quote: Originally Posted by DaveDog

I purchased one of the VALET tire presure monitoring systems, its available on ebay for less that $100 USD and it uses a separate display from the receiver.

It uses the same receiver PCB as FMode's waeco unit!!!

http://cgi.ebay.com/NEW-Valet-Tire-P...QQcmdZViewItem

I've taken the display and receivers apart to identify the communication protocol between the received and the display, looks like it uses a single wire LIN bus protocol, as the receiver uses a 6258 IC and the display uses a 6259-2 IC.

I noticed the PIC Robby used for his USB interface also supports LIN bus. If we can decode the communication, we might be able to modify Robby's PCB to communicate with this receiver, offering a somewhat affordable solution.

I bought one as well on ebay for $69, had the sensors installed yesterday. I must say this gadget works very well with the display, now if we can get the data to the PC taht would be great. At this cost you get a complete system for under $100.

DaveDog · 12-28-2007, 08:28 PM

I don't think we'll make it under $100, once we add up the cost of the PIC and associated electronics.

Dj-[NRG] · 12-29-2007, 04:56 AM

Quote: Originally Posted by DaveDog

I don't think we'll make it under $100, once we add up the cost of the PIC and associated electronics.

well, maybe for about 150USD?
btw, is there anyone starting to make this in a large number allready?
or are all people just waiting for others to do it? i've read some people have a working one allready, and someone got a price for 100 pieces of sensors, but other than that?
is there also someone who made a plugin for other frontends? like Centrafuse?
i think a lot of people would like this in their car, and the one that can make something for an acceptable price is going to make some money with it (too bad i don't know how to do this

)

anyway, if there is someone that makes this (then i mean complete plug and play hardware kit) and there would be plugins for other frontends (CF), then i will surely buy one if the price is under 200 USD...
if you have the sensors for 69USD, it should be possible to have all components for under 100USD, offcourse the builder has to make some profit, so i think 150 or even 175USD is a nice price, for the one who builds it as well for the the ones that buy it...
if ya sell 50 of it, you make easily 2500USD profit...

Greetz

Dj NRG

vicky_obee · 12-29-2007, 10:44 AM

Add me in .....
If some 1 is making on a large / small scale for a fair price... a complete pug and play...
I would like 1 as well
What say :-)

allypally · 12-29-2007, 03:53 PM

I also would be a buyer. Unfortunately, I am the first to admit that I understand very little of what technical matter that has been discussed here, and would contribute, if I knew how.
However, I would be a buyer, I am sure I would be able to sell a few units as well, so feel that if someone put the package together, as a plug and play, they would make money out of it.