0

ADS1015 - Measuring 0-1V at 12bit
Moderators: adafruit_support_bill, adafruit

Please be positive and constructive with your questions and comments.

ADS1015 - Measuring 0-1V at 12bit

by MrBaz on Tue Jan 08, 2019 4:53 pm

I need to measure a voltage output of 0V-1V.

The ADS1015 is 12bit, but after watching this video (https://www.youtube.com/watch?v=NWWFP09ZbJ4&t=309s) in that voltage range it would only be giving me ~2000 values between 0V-1V, since it is spec'd for 12bit across +/- 1V.
Can the libraries be changes to measure 4000 values across 0-1V?

MrBaz
 
Posts: 12
Joined: Fri Feb 03, 2017 12:57 pm

Re: ADS1015 - Measuring 0-1V at 12bit

by adafruit_support_bill on Tue Jan 08, 2019 5:52 pm

It is not a library issue. For maximum resolution with this chip, you need to use the differential measurement mode.

If you signal is 0v-1v, you can select the +/- 0.512v range. If you supply A0 with 0.5v, your 0-1v signal on A1 will be -.5v to +.5v relative to that.

adafruit_support_bill
 
Posts: 73049
Joined: Sat Feb 07, 2009 10:11 am

Re: ADS1015 - Measuring 0-1V at 12bit

by MrBaz on Wed Jan 09, 2019 12:12 am

adafruit_support_bill wrote:It is not a library issue. For maximum resolution with this chip, you need to use the differential measurement mode.

If you signal is 0v-1v, you can select the +/- 0.512v range. If you supply A0 with 0.5v, your 0-1v signal on A1 will be -.5v to +.5v relative to that.


If I use the +/- 0.512V range wouldn't I damage it if I put 1V on any of the analog inputs?

I'll be reading the output of a metal package PMT that outputs an analog voltage from 0V - 1V.

MrBaz
 
Posts: 12
Joined: Fri Feb 03, 2017 12:57 pm

Re: ADS1015 - Measuring 0-1V at 12bit

by adafruit_support_bill on Wed Jan 09, 2019 7:49 am

As long as all of your inputs are between GND and VCC, you will not damage the chip.

adafruit_support_bill
 
Posts: 73049
Joined: Sat Feb 07, 2009 10:11 am

Re: ADS1015 - Measuring 0-1V at 12bit

by MrBaz on Wed Jan 09, 2019 11:21 am

adafruit_support_bill wrote:As long as all of your inputs are between GND and VCC, you will not damage the chip.


Ah, I get it. You are using A0 as the control voltage and A1 as the actual measured input. Makes total sense now. Thanks!

MrBaz
 
Posts: 12
Joined: Fri Feb 03, 2017 12:57 pm

Please be positive and constructive with your questions and comments.