Implement real ADC readings with VND7050AJ sensor multiplexing

- Switch from simulated to real ADC readings in adc_sensor library
- Add GPIO control for VND7050AJ sensor selection (sen, s0, s1 pins)
- Implement proper ADC device and channel setup for voltage/current measurements
- Enable ADC driver in prj.conf (CONFIG_ADC=y)
- Disable simulation mode (CONFIG_ADC_SENSOR_SIMULATED=n)
- Add devicetree bindings for custom supply voltage and motor current sensors
- Update overlay with adc_sensors nodes using PB4, PB5, PB6 pins
- Integrate real ADC readings into Modbus server registers
- Support HSE/HSI clock source toggling in overlay configuration

software/apps/slave_node/prj.conf

@@ -22,4 +22,5 @@ CONFIG_MODBUS_BUFFER_SIZE=256
 
 # ADC Sensor Configuration - Use real ADC readings
 CONFIG_ADC_SENSOR_SIMULATED=n
+CONFIG_ADC=y
 

software/lib/adc_sensor/adc_sensor.c

@@ -24,6 +24,34 @@ LOG_MODULE_REGISTER(adc_sensor, LOG_LEVEL_INF);
 #define VOLTAGE_SENSOR_NODE DT_NODELABEL(supply_voltage)
 #define CURRENT_SENSOR_NODE DT_NODELABEL(motor_current)
 
+#ifndef CONFIG_ADC_SENSOR_SIMULATED
+// ADC device reference
+#if DT_NODE_EXISTS(VOLTAGE_SENSOR_NODE)
+#define ADC_NODE DT_PHANDLE(VOLTAGE_SENSOR_NODE, io_channels)
+#define ADC_CHANNEL DT_PHA(VOLTAGE_SENSOR_NODE, io_channels, input)
+#define ADC_RESOLUTION 12
+#define ADC_REFERENCE_MV DT_PROP(VOLTAGE_SENSOR_NODE, reference_mv)
+#define VOLTAGE_DIVIDER_RATIO \
+  DT_PROP(VOLTAGE_SENSOR_NODE, voltage_divider_ratio)
+
+static const struct device *adc_dev;
+static struct adc_channel_cfg adc_channel_cfg = {
+    .gain = ADC_GAIN_1,
+    .reference = ADC_REF_INTERNAL,
+    .acquisition_time = ADC_ACQ_TIME_DEFAULT,
+    .channel_id = ADC_CHANNEL,
+    .differential = 0};
+
+static struct adc_sequence adc_sequence = {
+    .channels = BIT(ADC_CHANNEL),
+    .buffer_size = sizeof(uint16_t),
+    .resolution = ADC_RESOLUTION,
+};
+
+static uint16_t adc_buffer;
+#endif
+#endif
+
 static bool initialized = false;
 
 #ifndef CONFIG_ADC_SENSOR_SIMULATED
@@ -165,6 +193,65 @@ static int set_current_sensor_gpios(bool enable, bool s0_state, bool s1_state) {
 }
 #endif /* !CONFIG_ADC_SENSOR_SIMULATED */
 
+#ifndef CONFIG_ADC_SENSOR_SIMULATED
+/**
+ * @brief Read ADC value and convert to millivolts
+ * @return ADC reading in millivolts, or 0 on error
+ */
+static uint16_t read_adc_voltage_mv(void) {
+#if DT_NODE_EXISTS(VOLTAGE_SENSOR_NODE)
+  int ret = adc_read(adc_dev, &adc_sequence);
+  if (ret < 0) {
+    LOG_ERR("ADC read failed: %d", ret);
+    return 0;
+  }
+
+  // Convert ADC reading to millivolts
+  // ADC reading is 12-bit (0-4095) representing 0 to ADC_REFERENCE_MV
+  uint32_t adc_value = adc_buffer;
+  uint32_t voltage_mv = (adc_value * ADC_REFERENCE_MV) / 4095;
+
+  // Apply voltage divider scaling
+  voltage_mv *= VOLTAGE_DIVIDER_RATIO;
+
+  LOG_DBG("ADC raw: %u, voltage: %u mV", adc_value, (uint16_t)voltage_mv);
+
+  return (uint16_t)voltage_mv;
+#else
+  return 0;
+#endif
+}
+
+/**
+ * @brief Read ADC value and convert to milliamps (for current sensor)
+ * @return ADC reading in milliamps, or 0 on error
+ */
+static uint16_t read_adc_current_ma(void) {
+#if DT_NODE_EXISTS(CURRENT_SENSOR_NODE)
+  int ret = adc_read(adc_dev, &adc_sequence);
+  if (ret < 0) {
+    LOG_ERR("ADC read failed: %d", ret);
+    return 0;
+  }
+
+  // Convert ADC reading to millivolts first
+  uint32_t adc_value = adc_buffer;
+  uint32_t voltage_mv = (adc_value * ADC_REFERENCE_MV) / 4095;
+
+  // Convert voltage to current based on current sensor characteristics
+  // Assuming a linear current sensor with specific mV/mA ratio
+  // This will need to be calibrated for your specific current sensor
+  uint32_t current_ma = voltage_mv / 10;  // Example: 10mV per mA
+
+  LOG_DBG("ADC raw: %u, current: %u mA", adc_value, (uint16_t)current_ma);
+
+  return (uint16_t)current_ma;
+#else
+  return 0;
+#endif
+}
+#endif
+
 int adc_sensor_init(void) {
   if (initialized) {
     return 0;
@@ -182,7 +269,25 @@ int adc_sensor_init(void) {
     return ret;
   }
 
-  // TODO: Initialize real ADC hardware
+  // Initialize ADC hardware
+#if DT_NODE_EXISTS(VOLTAGE_SENSOR_NODE)
+  adc_dev = DEVICE_DT_GET(ADC_NODE);
+  if (!device_is_ready(adc_dev)) {
+    LOG_ERR("ADC device not ready");
+    return -ENODEV;
+  }
+
+  adc_sequence.buffer = &adc_buffer;
+
+  ret = adc_channel_setup(adc_dev, &adc_channel_cfg);
+  if (ret < 0) {
+    LOG_ERR("Failed to setup ADC channel: %d", ret);
+    return ret;
+  }
+
+  LOG_INF("ADC device ready: %s", adc_dev->name);
+#endif
+
   LOG_INF("ADC sensor initialized (real ADC mode with GPIO control)");
 
 #if DT_NODE_EXISTS(VOLTAGE_SENSOR_NODE)
@@ -209,9 +314,8 @@ uint16_t adc_sensor_get_voltage_mv(void) {
   // Set GPIOs for voltage measurement (example: s0=0, s1=0 for channel 0)
   set_voltage_sensor_gpios(true, false, false);
 
-  // TODO: Read real ADC value for voltage
-  // For now return simulated value
-  uint16_t voltage = SIMULATED_VOLTAGE_MV;
+  // Read real ADC value for voltage
+  uint16_t voltage = read_adc_voltage_mv();
 
   // Disable sensor after measurement to save power
   set_voltage_sensor_gpios(false, false, false);
@@ -232,9 +336,8 @@ uint16_t adc_sensor_get_current_ma(void) {
   // Set GPIOs for current measurement (example: s0=1, s1=0 for channel 1)
   set_current_sensor_gpios(true, true, false);
 
-  // TODO: Read real ADC value for current
-  // For now return simulated value
-  uint16_t current = SIMULATED_CURRENT_MA;
+  // Read real ADC value for current
+  uint16_t current = read_adc_current_ma();
 
   // Disable sensor after measurement to save power
   set_current_sensor_gpios(false, false, false);