Intel Edison Fat Bike Tire Analyzer
by joe in Circuits > Microcontrollers
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Intel Edison Fat Bike Tire Analyzer
![P3040030.jpg](/proxy/?url=https://content.instructables.com/FH6/IX3M/IMWB92UD/FH6IX3MIMWB92UD.jpg&filename=P3040030.jpg)
![P3040025.jpg](/proxy/?url=https://content.instructables.com/F3A/PBQD/IMQLIZ8A/F3APBQDIMQLIZ8A.jpg&filename=P3040025.jpg)
If you fat bike, you talk about tire pressure. The goal for many is to run as low a pressure as possible. I was curious just how much it differed at various pressures.
So with that, an Intel Edison and Flex sensor were used to look at PSI.
Parts
![P3040020.jpg](/proxy/?url=https://content.instructables.com/FJQ/HNJW/IMQLIZDE/FJQHNJWIMQLIZDE.jpg&filename=P3040020.jpg)
I used the following parts:
Intel Edison Inventors Kit https://learn.sparkfun.com/tutorials/sparkfun-inv...
Flex Sensor: https://www.sparkfun.com/products/8606
Connect
![tireMonitor_bb.png](/proxy/?url=https://content.instructables.com/FTM/42YT/IMWB94UR/FTM42YTIMWB94UR.png&filename=tireMonitor_bb.png)
Wire up the flex sensor to A0 reading the postive leg, and + - to the flex sensor, with a resitor on the negative line.
Install
![P3040023.jpg](/proxy/?url=https://content.instructables.com/FO5/I69X/IMQLIZOT/FO5I69XIMQLIZOT.jpg&filename=P3040023.jpg)
The flex sensor was stuck to the inside of a Maxxis Minion FBF 4.8" tire on an 82mm DT Swiss rim.
Code
I used this code to read the ADC: https://github.com/humberto-garza/SparkFunEdisonAD...
I modified it to record the readings and take PSI as an input which is just used to make the filename. It is attached as tireTest.py . The results are stored in a CSV.
I graphed them in excel, manual I know, but I don't plan on repeating this much.
Results
![tireLog-Percent.png](/proxy/?url=https://content.instructables.com/FG0/N7TO/IMQLIZYW/FG0N7TOIMQLIZYW.png&filename=tireLog-Percent.png)
![TireLog-Roundness.png](/proxy/?url=https://content.instructables.com/FUS/VXG5/IMQLIZZN/FUSVXG5IMQLIZZN.png&filename=TireLog-Roundness.png)
So what is the most interesting here too me, the tire gets the most flex at 6 PSI! Not 4 like I would have assumed, and as you would assume it is the most round at 10 PSI. I would have assumed 4 was the most flat, but interestingly while 4 PSI does not provide the widest footprint it does react the most. By that I mean the profile of the tire changes the most at 4 PSI.
By no means is this groundbreaking research, but anytime you make a widget it is fun!