Problem with ADC

[Anonymous]

Hello everybody. I 'm trying to learn about ADC converter in PSOC using CY8CKIT-049-4xxx. I made a simple test by using a pot. However there are a few problems:

1. I never get 2047 on 3.3v. I get around 1375 counts.

2. I didn't figure how to use ADC_CountsTo_Volts function. When I call it it returns nothing - or at least this is what see on Uart Termonal.

Please see the attached files.

Thank you in advance

[Bob_Marlowe]

To print a float set in System view the heap size to 0x0200

Bob

[Anonymous]

Thank you for your answer.

Unfortunately it did not work.

I changed the CY8CKIT-049-4xxx with CY8CKIT-042 and now i'm able to read full scale. Maybe a faulty board? Don't know.

After I debugged the project now I know that ADC_CountsTo_Volts() function returns the correct value.

I have another question:

In datasheet is stated that ADC_IsEndConversion(ADC_WAIT_FOR_RESULT) "Does not return a result until the ADC conversion of all sequential channels is complete". What is the best way to use this function?

Again, thanks for your help.

[Anonymous]

Hello. What is your vref? 1.024v internal or vdd to vss?. And for float operation projrct build-linker float none must be true and also heap size must be 0x0200.

[Anonymous]

Hi.

Vref is 3.3V, so the range is VDAA to VSS.

[Anonymous · Accepted solution]

Hi all.

I finally managed to find the answer. And the board works now as expected.

According to the datasheet of the kit (page 63) VDDD and VDDA are tied together to VDD. In my case - the kit is powered from USB - VDD is 5V.

In PSoC Creator in "Design Wide Resources - System " VDDA and VDDD were set to 3.3V. By changing to 5.00V the problem is solved.

Thanks again everybody for help.