Diff: app/ad4110_support.c

Revision:

0:6ca37a8f8ba9

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/app/ad4110_support.c	Wed Jul 27 17:04:15 2022 +0530
@@ -0,0 +1,106 @@
+/***************************************************************************//*
+ * @file    ad4110_support.c
+ * @brief   AD4110 No-OS driver support file
+******************************************************************************
+ * Copyright (c) 2022 Analog Devices, Inc. All Rights Reserved.
+ *
+ * This software is proprietary to Analog Devices, Inc. and its licensors.
+ * By using this software you agree to the terms of the associated
+ * Analog Devices Software License Agreement.
+******************************************************************************/
+
+/******************************************************************************/
+/***************************** Include Files **********************************/
+/******************************************************************************/
+
+#include "app_config.h"
+#include "ad4110_iio.h"
+
+/******************************************************************************/
+/********************* Macros and Constants Definitions ***********************/
+/******************************************************************************/
+
+#define AD4110_LV_CHANNEL_PGA	    1
+
+/******************************************************************************/
+/******************** Variables and User Defined Data Types *******************/
+/******************************************************************************/
+
+/******************************************************************************/
+/************************** Functions Definitions *****************************/
+/******************************************************************************/
+
+/*!
+ * @brief Perform sign conversion for handling negative voltages in bipolar mode
+ * @param adc_raw_data[in] - ADC raw value
+ * @return ADC data after signed conversion
+ */
+int32_t perform_sign_conversion(uint32_t adc_raw_data)
+{
+	int32_t adc_data;
+	bool bipolar = ad4110_dev_inst->bipolar;
+
+	if (bipolar) {
+		adc_data =  adc_raw_data - ADC_MAX_COUNT_BIPOLAR;
+	} else {
+		adc_data = adc_raw_data;
+	}
+
+	return adc_data;
+}
+
+
+/*!
+ * @brief Convert the ADC raw value into equivalent RTD resistance
+ * @param adc_raw[in] - ADC raw sample
+ * @param rtd_ref[in] - RTD reference resistance in ohms
+ * @return RTD resistance value
+ * @note RTD is biased with constant excitation current. Below formula
+ *			is based on ratiometric measurement, where fixed value of RTD RREF
+ *			(reference resistor) and gain is taken into account
+ */
+float convert_adc_raw_into_rtd_resistance(uint32_t adc_raw, float rtd_ref)
+{
+	int32_t adc_data;
+	bool bipolar = ad4110_dev_inst->bipolar;
+
+	adc_data = perform_sign_conversion(adc_raw);
+
+	if (bipolar) {
+		return (((float)adc_data * rtd_ref) / (ADC_MAX_COUNT_BIPOLAR *
+						       AD4110_DEFAULT_PGA));
+	} else {
+		return (((float)adc_data * rtd_ref) / (ADC_MAX_COUNT_UNIPOLAR *
+						       AD4110_DEFAULT_PGA));
+	}
+}
+
+
+/*!
+ * @brief Convert the ADC raw value into equivalent voltage
+ * @param adc_raw[in]- ADC raw data
+ * @param channel_id - Channel ID (number)
+ * @return ADC voltage value
+ */
+float convert_adc_sample_into_voltage(uint32_t adc_raw, uint8_t channel_id)
+{
+	int32_t adc_data;
+	bool bipolar = ad4110_dev_inst->bipolar;
+	uint8_t gain = 0;
+
+	adc_data = perform_sign_conversion(adc_raw);
+
+	/* NOTE: PGA can be configured only for channel-0. The gain for the
+	 * other channels (LV Channels) is always 1 */
+	if (channel_id == HV_CHANNEL) {
+		gain = AD4110_DEFAULT_PGA;
+	} else {
+		gain = AD4110_LV_CHANNEL_PGA;
+	}
+
+	if (bipolar) {
+		return (adc_data * (AD4110_REF_VOLTAGE / (ADC_MAX_COUNT_BIPOLAR * gain)));
+	} else {
+		return (adc_data * (AD4110_REF_VOLTAGE / (ADC_MAX_COUNT_UNIPOLAR * gain)));
+	}
+}
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