ADC +5v and -5v read and compare

[DeAa_335316]

Hello,

   

I am using CY8C28445 (PSOC 1) ic . i have to use two ADC . first ADC calculate 5v to 0v and second ADC calculate -5v to 0. 

   

Both of ADC values i have to compare and turn on two separate  LED light .

   

ADC1 value  >  ADC2 value = LED 1 turn on 

   

ADC2 value  >  ADC1 value = LED 2 turn on 

   

Please provide the sample code for this task . i had test a basic code for +5v to 0 but i am not able to get 0 to -5v value .

       

Best Regards 

   

Deepak Aagri

[Bob_Marlowe]

The input to any pin on your PSoC may not be less than GND. So to measure a voltage < 0V you will have to level-shift it into the range of 0 .. 5V using an R ladder.

       

Bob

[DeAa_335316]

OK .. but i want to calculate multiple ADC value .. how i can switch pot ADC pin to different pin .
i only can use one ADCINC and my requirement is read to 4 input source separate value . is i need to change analogcolumn_inputmux port pin each time of interval to get all 4 channel value . if this is the right way for read multiple ADC value then please let me know how to write a code for multiple ADC read in run time .

[Bob_Marlowe]

Long time ago that I used that... Use an AMUX4 and configure it for your input pins. Look into datasheet for code example.

   

Keep in mind that the first 2 ADC samples after switching the mux are invalid.

   

Consider migrating to a 32 bit processor in a PSoC4. Kits available starting at $10. Including debugging capabilities!!!

       

Bob

[DeAa_335316]

Hi Bob,

   

Thanks for your advice but  Please share the mux code for  changing the input pin .... 

   

or tell me below code related to mux input pin change...

   

 AMUX4_InputSelect(BYTE bChannel);

[Bob_Marlowe]

What in the datasheet explanation is unclear?

           

Bob