cores/psoc6: Add the missing analog io implementation.

Signed-off-by: Ramya Subramanyam <[email protected]>

Author: ramya-subramanyam

cores/psoc6/analog_io.c

@@ -0,0 +1,91 @@
+#include "Arduino.h"
+#include "cyhal_adc.h"
+
+// Constants and Macros
+#define MIN_ACQUISITION_TIME        220
+#define adc_assert(cy_ret)          if (cy_ret != CY_RSLT_SUCCESS) { return 0xff; }
+
+// Type Definitions
+typedef struct {
+    pin_size_t pin;
+    cyhal_adc_channel_t chan_obj;
+    bool initialized;
+} adc_channel_t;
+
+// Static Variables
+static cyhal_adc_t adc_obj = {0};
+static cyhal_adc_vref_t desiredVRef = CYHAL_ADC_REF_VDDA;
+static bool adc_initialized = false;
+static adc_channel_t adc_channel[ADC_HOWMANY] = {0};
+
+// Helper Function: Initialize ADC hardware if not already done
+static cy_rslt_t initialize_adc(pin_size_t pinNumber) {
+    if (!adc_initialized) {
+        cy_rslt_t status = cyhal_adc_init(&adc_obj, mapping_gpio_pin[pinNumber], NULL);
+        adc_assert(status);
+        adc_initialized = true;
+    }
+
+    // Configure ADC settings
+    cyhal_adc_config_t adc_config = {
+        .continuous_scanning = false,
+        .resolution = ADC_RESOLUTION,
+        .average_count = 1,
+        .vneg = CYHAL_ADC_VNEG_VSSA,
+        .vref = desiredVRef,
+        .ext_vref = NC,
+        .bypass_pin = NC
+    };
+
+    return cyhal_adc_configure(&adc_obj, &adc_config);
+}
+
+static cy_rslt_t initialize_adc_channel(pin_size_t pinNumber, uint8_t adc_index) {
+    // Ensure ADC hardware is initialized
+    cy_rslt_t status = initialize_adc(pinNumber);
+    adc_assert(status);
+
+    // Configure individual ADC channel
+    cyhal_adc_channel_config_t chan_config = {
+        .enabled = true,
+        .enable_averaging = false,
+        .min_acquisition_ns = MIN_ACQUISITION_TIME
+    };
+
+    status = cyhal_adc_channel_init_diff(&adc_channel[adc_index].chan_obj, &adc_obj, mapping_gpio_pin[pinNumber], CYHAL_ADC_VNEG, &chan_config);
+    adc_assert(status);
+
+    adc_channel[adc_index].pin = pinNumber;
+    adc_channel[adc_index].initialized = true;
+
+    return status;
+}
+
+int analogRead(pin_size_t pinNumber) {
+    int adc_value = 0;
+    uint8_t adc_index = 0;
+
+    // Find existing channel or initialize a new one
+    for (adc_index = 0; adc_index < ADC_HOWMANY; adc_index++) {
+        if (adc_channel[adc_index].initialized) {
+            if (adc_channel[adc_index].pin == pinNumber) {
+                // Found an existing channel for the pin
+                break;
+            }
+        } else {
+            // Found an uninitialized channel, initialize it
+            cy_rslt_t result = initialize_adc_channel(pinNumber, adc_index);
+            adc_assert(result);
+            break;
+        }
+    }
+
+    if (adc_index < ADC_HOWMANY) {
+        adc_value = cyhal_adc_read(&adc_channel[adc_index].chan_obj);
+    }
+    return adc_value;
+}
+
+void analogReference(uint8_t mode) {
+    desiredVRef = CYHAL_ADC_REF_VDDA;
+}