ADC K64 output

[ahmedhrabi]

Hi everyone, 

I'am using the ADC16 of the k64. 

I'am using ADC0_DP1/ADC0_DM1 as differential Analogic voltage inputs.

The problem that i'am always getting as result the same value (3.3v that is the Vref) even when i change the input voltage value on the ADC0_DP1. 

Here is my code : 

#define ADC16_BASEADDR ADC0  //ID
#define ADC16_CHANNEL 0u //SC1A
#define ADC16_CHANNEL_NUMBER 1u //CHANNEL 1 (DP1)

#define VREF_BRD 3.300
#define SE_16BIT 65536.0
volatile uint32_t g_Adc16ConversionValue = 0;

ADC16_GetDefaultConfig(&adc16ConfigStruct);
ADC16_Init(ADC16_BASEADDR , &adc16ConfigStruct);
ADC16_EnableHardwareTrigger(ADC16_BASEADDR , false); 
if (kStatus_Success == ADC16_DoAutoCalibration(ADC0)) {
PRINTF("\r\nADC16_DoAutoCalibration() Done.");
} else {
PRINTF("ADC16_DoAutoCalibration() Failed.\r\n");
}
adc16ChannelConfigStruct.channelNumber = ADC16_CHANNEL_NUMBER ;
adc16ChannelConfigStruct.enableInterruptOnConversionCompleted = false;
adc16ChannelConfigStruct.enableDifferentialConversion = true; // enable diff mode
while (1)
{

//start new conversion
ADC16_SetChannelConfig(ADC16_BASEADDR , ADC16_CHANNEL , &adc16ChannelConfigStruct);

//wait conversion

while (0U == (kADC16_ChannelConversionDoneFlag & ADC16_GetChannelStatusFlags(ADC16_BASEADDR , ADC16_CHANNEL )))
{
}

//read converted value in ADC0 result register
g_Adc16ConversionValue = ADC16_GetChannelConversionValue(ADC16_BASEADDR , ADC16_CHANNEL);
voltRead = (float)(g_Adc16ConversionValue * (VREF_BRD / SE_16BIT));
PRINTF("\r\nADC Voltage: %0.3f v\r\n", voltRead);
}

[Hui_Ma]

Hi

Please refer attached tested code, which using FRDM-K64F board and can get ADC0_DP1 & ADC0_DM1 differential ADC conversion result.

I am using KSDK v2.0 for FRDM-K64F software. The project default path is :

C:\Freescale\SDK_2.0_FRDM-K64F\boards\frdmk64f\driver_examples\adc16\polling

Wish it helps.

Have a great day,
Ma Hui
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[ahmedhrabi]

Thx Hui_Ma i resolved my problem it was a hardware issue.