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Issues faced when working with CN0326 design

Question asked by adiga.girish on Feb 7, 2018
Latest reply on Feb 14, 2018 by adiga.girish

Hi,

 

I am facing couple of issues with CN0326 design.

 

Problem 1: With custom board and as well as CN0326 dev board. The code is written in C for a micro-controller to use SPI communication. The same steps have been followed as per the reference code. First the temperature is calculated. The I try to read the PH but then it fails. Same happens if I read PH first and then the temperature. Basically changing the channel is having some issue. So currently I have a work-around i.e. I initialize AD7793 everytime before I read  either temperature or the PH.

 

WORK AROUND

CN0326_CalculateTemp();
delayVar = 50000;
while(--delayVar);
AD7793_Init();
delayVar = 50000;
while(--delayVar);
CN0326_CalculatePH();
AD7793_Init();
delayVar = 50000;
while(--delayVar);

 

 

Problem 2:  Temperature reading also doesn't work as expected. It reads out a huge value. I have to read repeatedly till I get the value in the permissible range. Only then It works for me. Example as below.

 

do{

      CN0326_CalculateTemp();
      delayVar = 50000;
      while(--delayVar);
}while((temperatureVal > 60.0)|| (temperatureVal < -10.0));

 

Problem 3: Now I have several custom boards. The PT100 RTD is same. But each boards behave differently. The temperature variations between boards are in the range of + or - of 10 degree centigrade. I have followed almost same guidelines as in the development board. Not sure what is the issue.

 

Please help.

Thanks and regards,

Girisha.

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