Need ideas for TPMS project - Page 1
Forum section: electronics / projects

author: algis87
author_rank: Newbie
timestamp: January 30, 2016, 05:58:27 pm
content: Hello everyone,I need to do a project about TPMS (Tyre pressure monitoring system). I will need to create a MCU based wireless receiver (probably a PIC) with a LCD screen to collect data from the sensors. For project demonstration I only need one sensor.I was suggested to use existing aftermarket or OEM TPMS sensors. The problem is that I can't find datasheets for these sensors. I don't know their communication protocols. What I learned is that they mostly use 315/433Mhz FSK modulation, Manchester encoding but nothing more specific. I have seen someone hacking these sensors with data analyzers, but I can't afford such tools.Another route would be to design my own pressure sensor. By doing that, I could use different wireless standards like 433Mhz, Zigbee, bluetooth or something other. The problem would be power consumption as the sensors are battery powered. Also this would take more time to design both the sensor and receiver.So before I start I need your suggestions. Is it possible to use existing sensors for my project or should I design a new one?Any help is appreciated.

author: AndyC_772
author_rank: Super Contributor
timestamp: January 30, 2016, 07:27:58 pm
content: I'd have a go at reverse engineering the protocol. If you can obtain a suitable receiver, then making sense of the data can't possibly be that hard, and if you can't, then the decision is made for you.

author: NiHaoMike
author_rank: Super Contributor
timestamp: January 31, 2016, 05:24:05 am
content: Grab a RTLSDR and have a try at reverse engineering.

author: zoltan
author_rank: Contributor
timestamp: March 14, 2016, 09:57:42 am
content: I'm in the process of reverse engineering a TPMS protocol.The final goal is to build a receiver for my car using RFM69 module and microcontroller. Planned to share it here once it's up and running.My sensor is Schraeder 433 MHz with ASK and manchester encoding. You can find more info here:https://groups.google.com/forum/#!topic/rtl_433/MIW40yGrUiAPartial datasheet can be found through FCC reports, and some insight is given by FCC test reports. I recommend you to not try making your own sensor, instead use off the shelf ones (<$10 on ebay - new unused). They are mechanically sturdy, suitable for use in tire, unlike a homebrew variant.

author: jh15
author_rank: Frequent Contributor
timestamp: March 14, 2016, 01:26:21 pm
content: I just bought this from Amazon:http://www.amazon.com/CARCHET-Pressure-Monitoring-Intelligent-External/dp/B012AEEYDM/ref=sr_1_3?s=automotive&ie=UTF8&qid=1457961457&sr=1-3Maybe these transmitters would work better for your research.I had bought a Schrader internal replacement, but Sears couldn't activate it after new tires.This entire kit cost only a little more than my Schrader, and besides, my 2008 Honda Element is old enough where more could fail at any time.I've only plugged the display in and it looks great.Also it does tire temperature, audible alarms for preset pressures, and alarm for sudden deflation rate, much better than oem function.Now I have to pull dashboard to disable orange tpms LED or put black tape over it.I'll post back here if it works well.Oh, also user replaceable batteries, wish I found this a year ago.. stupid light on all the time.

author: zoltan
author_rank: Contributor
timestamp: March 14, 2016, 03:05:50 pm
content: Those sensors from amazon are not nearly as good as internal ones.They are easy to steal, they rely on internal rubber seal and keep the valve open all the time, and they add unneccessary mass to the valve stem.IMHO not worth the price.All internal tpms sensors report pressure and temperature as standard feature, plus the ability to send alarm in the case of rapid deflation. The problem lies in greedy automakers, who gives you only a yellow warning light as mandated by law. For anything more you have to pay extra.

author: crispus
author_rank: Regular Contributor
timestamp: February 07, 2019, 07:44:44 pm
content: Quote from: jh15 on March 14, 2016, 01:26:21 pmIf you have to change the pressure pretty frequent (for offroad) that thing wouldn't help you.Quote from: zoltan on March 14, 2016, 09:57:42 amDid you make any progress?