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Variable gain ADC feature #240

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merged 3 commits into from
May 5, 2023
Merged

Variable gain ADC feature #240

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efaeb6d
diff gain working
boramonideep Apr 28, 2023
e73be6f
final changes for ADC gain stage enable
boramonideep May 2, 2023
448e285
added macros for ADC variable gain
boramonideep May 5, 2023
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64 changes: 64 additions & 0 deletions cores/wiring_analog.c
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Original file line number Diff line number Diff line change
Expand Up @@ -216,6 +216,70 @@ if( channel < NUM_ANALOG_INPUTS )
return value;
}

/* analogRead_variableGain takes parameter of ADC channel number and gain value
return 0xFFFFFFFF for invalid channel

gain value gain factor
0 1
1 3
2 6
3 12
Also, refer to macros in wiring_analog.h
*/

uint32_t analogRead_variableGain( uint8_t channel, uint8_t gain_value )
{
#if(XMC_VADC_SHS_AVAILABLE == 1U)
uint32_t value;

value = 0xFFFFFFFF;
if( channel < NUM_ANALOG_INPUTS )
{
XMC_ADC_t *adc = &mapping_adc[ channel ];

#if(XMC_VADC_GROUP_AVAILABLE == 1U)
// ADC grouping
if( !(adc->enabled) )
{
XMC_VADC_CHANNEL_CONFIG_t vadc_gobal_channel_config;
memset( &vadc_gobal_channel_config, 0, sizeof( XMC_VADC_CHANNEL_CONFIG_t ) );
vadc_gobal_channel_config.input_class = XMC_VADC_CHANNEL_CONV_GROUP_CLASS1;
vadc_gobal_channel_config.result_reg_number = adc->result_reg_num;
vadc_gobal_channel_config.alias_channel = XMC_VADC_CHANNEL_ALIAS_DISABLED;

XMC_VADC_RESULT_CONFIG_t vadc_gobal_result_config = { .g_rcr = 0 };
/* Configure a channel belonging to the aforesaid conversion kernel */
XMC_VADC_GROUP_ChannelInit( adc->group, adc->channel_num, &vadc_gobal_channel_config );
/* Configure a result resource belonging to the aforesaid conversion kernel */
XMC_VADC_GROUP_ResultInit( adc->group, adc->result_reg_num, &vadc_gobal_result_config );
/* Add channel into the Background Request Source Channel Select Register */
XMC_VADC_GLOBAL_BackgroundAddChannelToSequence( VADC, (uint32_t)adc->group_num,
(uint32_t)adc->channel_num );
/* Set the gain factor of the Sample and hold module*/
XMC_VADC_GLOBAL_SHS_SetGainFactor( SHS0, gain_value, (uint32_t)adc->group_num, (uint32_t)adc->channel_num );
}
/* Start conversion manually using load event trigger*/
XMC_VADC_GLOBAL_BackgroundTriggerConversion( VADC );
value = XMC_VADC_GROUP_GetResult( adc->group, adc->result_reg_num );
#else
// XMC1100 no ADC grouping
if( !(adc->enabled) )
/* Add a channel to the background source. */
VADC->BRSSEL[ ADC_CONVERSION_GROUP ] = (uint32_t)( 1U << adc->channel_num );
/* Set the gain factor of the Sample and hold module */
XMC_VADC_GLOBAL_SHS_SetGainFactor( SHS0, gain_value, XMC_VADC_GROUP_INDEX_0, (uint32_t)adc->channel_num );
// Generates conversion request
XMC_VADC_GLOBAL_BackgroundTriggerConversion( VADC );

// Wait until conversion is ready
while( ( ( value = XMC_VADC_GLOBAL_GetDetailedResult( VADC ) ) & VADC_GLOBRES_VF_Msk) == 0u );
#endif
value = ( ( value & VADC_GLOBRES_RESULT_Msk) >> ( ADC_MAX_READ_RESOLUTION - _readResolution ) );
return value;
}
#endif
}


/* Helper function for analogWrite and setAnalogWriteFrequency to scan
mapping tables to determine for a given pin which PWM4, PWM8 or DAC
Expand Down
25 changes: 25 additions & 0 deletions cores/wiring_analog.h
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Original file line number Diff line number Diff line change
Expand Up @@ -26,6 +26,15 @@
extern "C" {
#endif

/*********************************************************************************************************************
* MACROS
********************************************************************************************************************/
// ADC gain macros
#define ADC_VAR_GAIN_FACTOR_1 0
#define ADC_VAR_GAIN_FACTOR_3 1
#define ADC_VAR_GAIN_FACTOR_6 2
#define ADC_VAR_GAIN_FACTOR_12 3

//****************************************************************************
// @External Prototypes
//****************************************************************************
Expand Down Expand Up @@ -85,6 +94,22 @@ extern "C" {
*/
extern uint32_t analogRead( uint8_t channel ) ;

/*
* \brief Reads the value from the specified analogue channel and add variable gain at input.
*
* \param channel
* \param gain_factor
*
* gain value gain factor
* 0 1
* 1 3
* 2 6
* 3 12
*
* \return Read value from selected channel, or 0xFFFFFFFF for error.
*/
extern uint32_t analogRead_variableGain( uint8_t channel, uint8_t gain_value ) ;

/*
* \brief Set the resolution of analogRead return values in number of bits.
* \note Default is 10 bits (range from 0 to 1023).
Expand Down
1 change: 1 addition & 0 deletions keywords.txt
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Expand Up @@ -16,6 +16,7 @@ getAnalogReadBits KEYWORD2
getAnalogWriteBits KEYWORD2
getAnalogReadMaximum KEYWORD2
getAnalogWriteMaximum KEYWORD2
analogRead_variableGain KEYWORD2

#######################################
# Instances (KEYWORD2)
Expand Down