PSoC4PS : Maintaining Accuracy With Small Magnitude Signals application

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MiNe_85951
Level 7
Level 7
Distributor - TED (Japan)
50 likes received 500 replies posted 50 solutions authored

Dear Sirs and Madams,

 

We are considering PSoC4PS for the analog front end of the strain sensor.

We found the following materials from the website :

 

Maintaining Accuracy With Small Magnitude Signals URL

https://www.cypress.com/file/104761/download

 

Do you have an application note with detailed information on this document?

I understand the hardware configuration, However We would like to know how the software algorithms are done.

 

Regards,

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1 Solution
DennisS_46
Employee
Employee
100 sign-ins 50 likes received 50 solutions authored

This article is sort of stand-alone, it does not include code and there is no code example for it.
If your are trying to read low voltage values using gain, correlated double sampling does a fine job of reducing
1/f noise and offset drift. You can also improve calibration this way to reduce the gain errors in the PGAs shown
in the article. This technique is described in AN2226 using PSoC1 to measure thermocouples. I wrote this in 2008, but the underlying math and physics don't change and it's easily found with a google search. I would make a few changes to the circuit used by my friend Pushek in the article. I'll be happy to share them with you by email or phone. I work from home in Montana, call during usual business hours and we can take as much time as you like.
---- Dennis Seguine
Cypress Lead applications engineer
dennis.seguine@infineon.com
1-425-770-5165

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2 Replies
DennisS_46
Employee
Employee
100 sign-ins 50 likes received 50 solutions authored

This article is sort of stand-alone, it does not include code and there is no code example for it.
If your are trying to read low voltage values using gain, correlated double sampling does a fine job of reducing
1/f noise and offset drift. You can also improve calibration this way to reduce the gain errors in the PGAs shown
in the article. This technique is described in AN2226 using PSoC1 to measure thermocouples. I wrote this in 2008, but the underlying math and physics don't change and it's easily found with a google search. I would make a few changes to the circuit used by my friend Pushek in the article. I'll be happy to share them with you by email or phone. I work from home in Montana, call during usual business hours and we can take as much time as you like.
---- Dennis Seguine
Cypress Lead applications engineer
dennis.seguine@infineon.com
1-425-770-5165

odissey1
Level 9
Level 9
First comment on KBA 1000 replies posted 750 replies posted

MaMi,

For a strain sensor measurement, you may consider using external 24-bit DelSig-ADC, HX711, similar to project

HX711: 24-bit Delta Sigma ADC interface for weight scale using PSoC 

 

The weight load in this project is also based on strain sensor, so it should be adequate.

Note that unlike PSoC5, PSoC4 lacks Delta-Sigma ADC, so HX711 can provide entire analog front end for just about $1.

/odissey1

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