Feat: add loop to main to read adc data

Refs: #4

src/main/esp32_eurorack_generic.c

@@ -10,6 +10,7 @@
 #include "freertos/task.h"
 #include "freertos/portmacro.h"
 #include "hal/adc_types.h"
+#include "soc/soc_caps.h"
 
 /* ADC input pins */
 #define ADC_INPUT_1_PIN 4
@@ -17,6 +18,8 @@
 #define ADC_INPUT_3_PIN 9 /* TODO Reroute from pin 46 to 9 on schematic, cant do ADC */
 #define ADC_INPUT_4_PIN 10
 
+#define ADC_READ_LEN 256
+
 /* ADC channels */
 static adc_channel_t channel[4] = {ADC_CHANNEL_3, ADC_CHANNEL_5, ADC_CHANNEL_8, ADC_CHANNEL_9};
 
@@ -67,7 +70,7 @@ static void adc_cont_init(void)
   /* Create continuous mode driver handle */
   adc_continuous_handle_cfg_t adc_handle_config = {
     .max_store_buf_size = 1024,
-    .conv_frame_size = 100
+    .conv_frame_size = ADC_READ_LEN
   };
   ESP_ERROR_CHECK(adc_continuous_new_handle(&adc_handle_config, &adc_handle));
 
@@ -108,6 +111,29 @@ void app_main(void)
   adc_task_handle = xTaskGetCurrentTaskHandle();
   ESP_ERROR_CHECK(adc_continuous_start(adc_handle));
 
+  esp_err_t adc_ret;
+  uint32_t ret_num = 0;
+  uint8_t result[ADC_READ_LEN] = {0};
+
+  while (1) {
+    /* Perform a read */
+    adc_ret = adc_continuous_read(adc_handle, result, ADC_READ_LEN, &ret_num, 0);
+    if (adc_ret == ESP_OK) {
+      for (int i = 0; i < ret_num; i+= SOC_ADC_DIGI_RESULT_BYTES) {
+        /* Grab the data and channel number */
+        adc_digi_output_data_t *p_data = (void*)&result[i];
+        uint32_t chan = ((p_data)->type2.channel);
+        uint32_t data = ((p_data)->type2.data);
+        /* Check channel number to see if data is bogus */
+        if (chan < SOC_ADC_CHANNEL_NUM(ADC_UNIT_1)) {
+          ESP_LOGI("adc", "ADC_1_%"PRIu32" value: %"PRIx32, chan, data);
+        } else {
+          ESP_LOGW("adc", "Invalid data from ADC_1_%"PRIu32, chan);
+        }
+      }
+    }
+  }
+
   /* Cleanup ADC */
   adc_cleanup();
 }