Recommendation on amplifier for pressure sensor?

Thread Starter

ataveras64

Joined Jun 11, 2020
2
I have project that has to do with measuring tire pressure from a range of 0-60 PSI. The corresponding voltage range is from 0.486v to 1v. Looking for recommendations on amplifiers for a case like this, i will be feeding the output into an arduino nano to use for programming. I am new to amplifiers and electronics in general but I know the basics pretty well.

Right now I wish I was an E.E. instead of an M.E., but ill learn.
 

djsfantasi

Joined Apr 11, 2010
6,711
I have project that has to do with measuring tire pressure from a range of 0-60 PSI. The corresponding voltage range is from 0.486v to 1v. Looking for recommendations on amplifiers for a case like this, i will be feeding the output into an arduino nano to use for programming. I am new to amplifiers and electronics in general but I know the basics pretty well.

Right now I wish I was an E.E. instead of an M.E., but ill learn.
Why do you think you need an amplifier? The Arduino’s ADC will measure a voltage in increments of about 5mV. It will give you approximately 100 different values for the range you specify. Without any amplification.
 

drc_567

Joined Dec 29, 2008
869
... No expert, but as I recall, the Uno Arduino has a convenient means to set the internal voltage reference, so that you get a proportional reading of 1024 counts between 0 and 1 volt, rather than 0 to 5 volts.
... There is a book that seems to have reasonably clear explanations.:
John Boxall
Arduino Workshop: A Hands-On Introduction with 65 Projects
 

Thread Starter

ataveras64

Joined Jun 11, 2020
2
I have actually read that book recently, and yes I didn't consider using the reference voltage feature. My plan before was to amplify the signal then filter it with using a high pass filter configuration. The reason why I was going that route was because the incoming signal from the sensor had a little more variation than I would like it to, after doing the required conversion within the programming my output in PSI has a variation of around 3-4 PSI while the pressure is steady.

Another issue I had was getting the correct slope increment of the sensor(mV/PSI), as the pressure increase the slope increases. For example, at 15 PSI the average slope is 8 but at about 45 PSI the slope is almost 11. The slope is suppose to be linear according to the datasheet but my reading don't confirm it.

I will try with the reference voltage on the arduino
 

Reloadron

Joined Jan 15, 2015
5,609
The Arduino, depending on chip, can use an internal 1.1 volt analog reference, analogReference() which would likely work out well for you. So 0 to 1.1 volts at analog in gives you a 0 to 1023 bit count. That results in a nice enough resolution for what you have. from 0.486v to 1v. Just write your code accordingly and for example use a map function.

Ron

Just saw your mention of filtering. Yes, you would like a linear slope. If the data sheet claims linear it should be linear. I would question it. You can map non-linear in your code but use plenty of points.
 
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