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ADS1115 PROBLEMS
Moderators: adafruit_support_bill, adafruit

Please be positive and constructive with your questions and comments.

Re: ADS1115 PROBLEMS

by Stamos on Wed Jun 21, 2017 4:54 pm

Thats the best answer i could have today from any person !!

If i dont want to use Divider, can i put negative terminal to ADS1115, or doesnt work like that?

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Re: ADS1115 PROBLEMS

by Stamos on Wed Jun 21, 2017 4:56 pm

Also can you give me a schematic , my mind is melt now

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Re: ADS1115 PROBLEMS

by adafruit_support_bill on Wed Jun 21, 2017 5:32 pm

Something like this:
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Re: ADS1115 PROBLEMS

by Stamos on Wed Jun 21, 2017 5:40 pm

seems brilliant! but a 2:1 wont give me 11.3/2 voltage?? isnt it 5.65 volts in each input???
Also i keep the same grounds on ADS 1115 AS I HAD IT on my schematic and keep what you told me as the only addition???

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Re: ADS1115 PROBLEMS

by Stamos on Wed Jun 21, 2017 5:41 pm

sorry i am asking so much but you know each ADS1115 costs 18euros in greece

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Re: ADS1115 PROBLEMS

by adafruit_support_bill on Wed Jun 21, 2017 6:17 pm

All the grounds would be to the negative terminal of your 12v supply.

With a voltage of 11.3v across the 2:1 voltage divider as shown, there will be a 7.53v drop across the 2K resistor and a 3.77v drop across the 1K resistor. So the maximum your ADS1115 would see relative to its ground would be 3.77v.

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Re: ADS1115 PROBLEMS

by Stamos on Wed Jun 21, 2017 6:24 pm

Tomorrow i get my new Parts, so i will work on them, unfortunatelly i am in a place away from shops so now i got to order resistors for dividers (i an a student as i told you and i dont have kits e.t.c.)...

Thanks man, you really helped me!1 i sorted somethings out... it took me 3 months to find it out

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Re: ADS1115 PROBLEMS

by Stamos on Thu Jun 22, 2017 6:08 am

Kalispera Friend (goodevening)

This is my last scematic, with blue pen circles is the changes, can you confirm?
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Re: ADS1115 PROBLEMS

by adafruit_support_bill on Thu Jun 22, 2017 6:23 am

Yes, that looks OK.

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Re: ADS1115 PROBLEMS

by Stamos on Thu Jun 22, 2017 6:31 am

Thank you!!

If i have something new i will inform you
i hope everything works

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Re: ADS1115 PROBLEMS

by Stamos on Tue Jun 27, 2017 12:27 pm

Hello Bill

i face a problem of linearity after the voltage divider!!

In low values around 50mV , after the voltage divider i got 10mV
After 1V i got a normal factor 3 times lower values

Before 1V i got a range of 5times lower value ,3.54 , 3.31 , 3.15 do i need to find an equation for this?

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Re: ADS1115 PROBLEMS

by adafruit_support_bill on Tue Jun 27, 2017 4:21 pm

It is not clear from your description what exactly you are measuring. Please show us how you are making thee measurements.

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Re: ADS1115 PROBLEMS

by Stamos on Tue Jun 27, 2017 4:35 pm

the schematic is like this we had.
Also, i will get the prices i want from the emmiter also, can i measure there without any divider?
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Re: ADS1115 PROBLEMS

by adafruit_support_bill on Tue Jun 27, 2017 4:43 pm

Yes, I am familiar with the circuit. But you didn't answer my question. What exactly are you measuring in that circuit?
In low values around 50mV , after the voltage divider i got 10mV

50mV between what two points in the circuit? What did you use to measure that?
Before 1V i got a range of 5times lower value ,3.54 , 3.31 , 3.15 do i need to find an equation for this?

3.54 what? Volts? Millivolts? What are you measuring and how are you measuring it? Please me specific.

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Re: ADS1115 PROBLEMS

by Stamos on Tue Jun 27, 2017 4:50 pm

i used Multimeter before i use my ADS!!

3.54 i mean times Lower price (the prices i told you are factors). mean i didnt get (30mV bofore voltage divider and after 10mV) or (60mV-20mV)

i dont like Voltage divider there, can i go with the circuit i will attach?? i got the same prices i need but with lower voltages instead..

Sorry for being tyring
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Please be positive and constructive with your questions and comments.