topic Re: TPMS Sensors in Sensors

TPMS Sensors

lalit0611 — Tue, 03 Feb 2026 20:58:35 GMT

Hi,

I am very new to TPMS sensors, I just read about them and though that it would be cool to fit them in my car.So I was looking at FXTH87 sensors, but I could not figure out how the sensor is going to read the tyre pressure and where will it be fit on the wheel? Also I looked at the FXTH87 Evaluation Manual, it said that a BDM Multilink is required to program the chip, but it appears that is being discontinued and will be taken over by UMultiLink, but I couldn't find the FXTH87 name under the supported micro-controllers. Can someone clarify on that too?

Thanks in advance for the help

Re: TPMS Sensors

david_diaz — Wed, 19 Aug 2015 23:01:06 GMT

Hello,

First of all, please refer to the Tire Pressure Monitoring System (TPMS) main web page in order to get more information, recommended products, demos and documentation, at:

Tire Pressure Monitoring System (TPMS)|Freescale

With regard to your first questions, I would like to recommend the following document:

A Global Solution for Tire Pressure Monitoring System

The document mentioned addresses the requirements of tire pressure monitoring systems and variations in implementing them as well as the latest technology for a system-in-package solution and a discussion about advancements that could occur in the near future.

Regarding your last question, The FXTH87 has an S08, 8-bit microprocessor core, therefore you would require a universal BDM and CodeWarrior to program it.

I would recommend you the following BDM interface:

Universal Multilink Development Interface|Freescale

I hope all this information will be useful for you. In case you still have questions or you need me to be more specific, please let me know. I will be glad to help.

Have an excellent day :smileyhappy:

David

Re: TPMS Sensors

lalit0611 — Thu, 20 Aug 2015 05:59:32 GMT

Your post answers most of my questions. But I'm unable to figure out where on tyre will TPMS be mounted and how does it measure the pressure? Does it work like those manual pressure gauge, where you put the device over tyre valve and let some air out to check the pressure or something different. Sorry if it's a silly question but I'm unable to imagine how it'll fit over the tyre :smileysad:

Re: TPMS Sensors

timgillman — Thu, 20 Aug 2015 18:00:07 GMT

If you look on the block diagram on the page previously mentioned, you will see that it uses RF communications. The sensors go inside the tires : Tire Pressure Monitoring System (TPMS)|Freescale

Re: TPMS Sensors

sushilnikam — Fri, 21 Aug 2015 05:27:34 GMT

HI Lalit,

Basically there are two methods of mounting the sensor

1. Inside the tyre

2. Outside the tyre means on the valve of the tyre.

For example if you put the sensor on the valve (outside the tyre) it has to push the valve so that the AIr Pressure will be force on the TPMS chip. As the TPMS application chip is having on chip pressure sensor it will sense the pressure and provide you the corresponding data. To understand the complete system you have to study the Internal Architecture of it. Its very difficult for me to tell you whole thing here.

Thanks & Regards

Sushil

Re: TPMS Sensors

lalit0611 — Fri, 21 Aug 2015 05:30:22 GMT

This is exactly what my doubt was. Thanks Sushil, Tim and David for clearing my doubts :smileyhappy:

Re: TPMS Sensors

lalit0611 — Fri, 21 Aug 2015 09:35:29 GMT

One last doubt (in this post :smileysilly: ), is this the right version of Code Warrior?

CodeWarrior for Microcontrollers-Eclipse IDE|Freescale

Re: TPMS Sensors

sushilnikam — Fri, 21 Aug 2015 11:54:14 GMT

Please go through link

http://cache.freescale.com/files/sensors/doc/support_info/FXTH87-CW10.6-SETUP.pdf