From 2abdd7be0cc77d23ba36734704ef48cca84cf56f Mon Sep 17 00:00:00 2001
From: rkcf <rkcf@rkcf.me>
Date: Tue, 21 Feb 2023 05:57:42 -0600
Subject: [PATCH] Feat: add ADC callback on conversion done

Refs: #4
---
 src/main/esp32_eurorack_generic.c | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)

diff --git a/src/main/esp32_eurorack_generic.c b/src/main/esp32_eurorack_generic.c
index 84ff232..bd39c74 100644
--- a/src/main/esp32_eurorack_generic.c
+++ b/src/main/esp32_eurorack_generic.c
@@ -1,10 +1,14 @@
 #include <stdio.h>
 
+#include "esp_attr.h"
 #include "esp_err.h"
 #include "esp_log.h"
 #include "esp_adc/adc_cali.h"
 #include "esp_adc/adc_cali_scheme.h"
 #include "esp_adc/adc_continuous.h"
+#include "freertos/FreeRTOS.h"
+#include "freertos/task.h"
+#include "freertos/portmacro.h"
 #include "hal/adc_types.h"
 
 /* ADC input pins */
@@ -19,10 +23,20 @@ static adc_channel_t channel[4] = {ADC_CHANNEL_3, ADC_CHANNEL_5, ADC_CHANNEL_8,
 /* ADC handles */
 static adc_continuous_handle_t adc_handle;
 static adc_cali_handle_t adc_cali_handle;
+static TaskHandle_t adc_task_handle;
 
 static const char *TAG = "EERG";
 
 
+/* ADC conversion finished callback */
+static bool IRAM_ATTR adc_conv_cb(adc_continuous_handle_t handle, const adc_continuous_evt_data_t *edata, void *user_data)
+{
+  BaseType_t mustYield = pdFALSE;
+  /* Send notification to handler task */
+  vTaskNotifyGiveFromISR(adc_task_handle, &mustYield);
+  return (mustYield == pdTRUE);
+}
+
 /* Deinitializes ADC handles */
 static void adc_cleanup(void)
 {
@@ -75,6 +89,12 @@ static void adc_cont_init(void)
   }
   adc_config.adc_pattern = adc_pattern;
   ESP_ERROR_CHECK(adc_continuous_config(adc_handle, & adc_config));
+
+  /* Configure callbacks */
+  adc_continuous_evt_cbs_t cbs = {
+    .on_conv_done = adc_conv_cb
+  };
+  ESP_ERROR_CHECK(adc_continuous_register_event_callbacks(adc_handle, &cbs, NULL));
 }
 
 void app_main(void)
@@ -85,6 +105,7 @@ void app_main(void)
   /* Initialize continuous driver */
   adc_cont_init();
   /* Start the continuous driver */
+  adc_task_handle = xTaskGetCurrentTaskHandle();
   ESP_ERROR_CHECK(adc_continuous_start(adc_handle));
 
   /* Cleanup ADC */