CS5460A adc and LOAD CELL

[nick703]

hello friend ,

i want to calculation weight of load cell using cs5460a to pic32 . if anyone has any reference to read adc value and how to transform weight (0 to 100kg) then please help me.
load cell capacity is o to 100kg.

 

[nick703]

i have read adc value and this is display in lcd between 0 to 65535 range . but when no load on load cell then reading is constant like 4566 so i want to say what is the exact calculation to display exact weight on my lcd using 24-bit Adc .
please help me !!

 

[keith1200rs]

You need to show your circuit.

Keith

 

[nick703]

thanks for replay keith1200rs i attached doc file ok.

View attachment Using Load Cell to Calculate Weight.rar

 

[nick703]

and also i want to know how to create exact calculation of weight with resolution up-to 1 gram. my load cell excited voltage is +5v .

 

[keith1200rs]

The CS5460A seems a strange choice for an ADC - it is a "Single Phase, Bi-directional Power/Energy IC". I assume the load cell is a strain gauge bridge. As far as I can tell it is recommended to excite it with 9 to 12V although I cannot see why lower voltages wouldn't work. However, you only get 2mV/V out of it, full scale so will need a fair gain to get a decent signal. The PGA in the CS5460 is x50 maximum so you will not get high accuracy from only 10mV input.

Two resistors off the 5V supply don't make for a good reference. The CS5460 has one built in so why not use that?

Does your digital output value vary with load?

Keith

 

[nick703]

yes my digital output value vary with load cell . when no weight on load cell then give me result 4353 and when i put some load this value change to above the value of 4353 .
and also i don't about load cell scenario when i put some load on both side after one by one then result is opposed . like one side greater then 4353 digital value and other side less then 4353 digital value .
And here is the link to use cs5460a . so i use this adc.
https://sssysinfotech.blogspot.in/2010/09/weigh-scale-using-adc-cs5460-and.html

if any calculation or example must be help !!

 

[keith1200rs]

Measure the voltage on the two output leads of the load cell - they should be 2.5V with no load.

Keith

 

[nick703]

yes u r right i measured this voltage is 2.5v. i got it but what is a factor to calculate on this basic referance volatage 2.5v.
??

 

[keith1200rs]

The voltage difference between the two pins is approximately 2mV/V full scale. So, if you are applying 5V to the bridge you will get 10mV full scale. Measure the voltage with a multimeter between the two pins - it should be zero with no load. The CS5460 should therefore also give zero.

Keith

 

[nick703]

u means measure the voltage on IIN+ and IIN- pin of cs5460a which directly connected to the output of load cell?
that's give me a result of 0 volt without load and with load using of multimeter ? so what can i do ?

 

[keith1200rs]

The voltage difference will be very small - 10mV at most when you place a load on the load cell - but you should be able to see that on a multimeter.

Keith

 

[nick703]

i didn't see the voltage difference but ADC reading is i getting when load put on load cell . so any coding problem if u help me then i post my little adc code.

 

[nick703]

hey kaith i getting value of ADC when of 1101 , 1201 ,(HEX) so on .. at that time original value is like that 1101 25 (HEX)something i neglecting lower value of ADC and i get only 1101 . so my question is if i have a count value every time 100 (HEX) value then how to calculate weight ?

 

[keith1200rs]

I would suggest you test your ADC and software with known voltages (i.e. not the load cell) to make sure you are operating it correctly.

Keith

 

[nick703]

if no load cell is connected then how my result of ADC vary ?

 

[akt29]

if no load cell is connected then how my result of ADC vary ?

Can u send me code of interfacing CS5460 i want it for my development.

Thanks in advance....