From 01a4b4e82f9037b25565f694207b2be329d7f40d Mon Sep 17 00:00:00 2001
From: Otto Winter <otto@otto-winter.com>
Date: Tue, 20 Jul 2021 07:05:56 +0200
Subject: [PATCH] ESP32 ADC use esp-idf (#2024)

Co-authored-by: Jesse Hills <3060199+jesserockz@users.noreply.github.com>
---
 esphome/components/adc/adc_sensor.cpp | 52 +++++++++++++++++++++------
 esphome/components/adc/adc_sensor.h   |  8 +++--
 esphome/components/adc/sensor.py      |  8 ++---
 3 files changed, 51 insertions(+), 17 deletions(-)

diff --git a/esphome/components/adc/adc_sensor.cpp b/esphome/components/adc/adc_sensor.cpp
index 960d9ed8e2..d6469ab785 100644
--- a/esphome/components/adc/adc_sensor.cpp
+++ b/esphome/components/adc/adc_sensor.cpp
@@ -11,7 +11,30 @@ namespace adc {
 static const char *const TAG = "adc";
 
 #ifdef ARDUINO_ARCH_ESP32
-void ADCSensor::set_attenuation(adc_attenuation_t attenuation) { this->attenuation_ = attenuation; }
+void ADCSensor::set_attenuation(adc_atten_t attenuation) { this->attenuation_ = attenuation; }
+
+inline adc1_channel_t gpio_to_adc1(uint8_t pin) {
+  switch (pin) {
+    case 36:
+      return ADC1_CHANNEL_0;
+    case 37:
+      return ADC1_CHANNEL_1;
+    case 38:
+      return ADC1_CHANNEL_2;
+    case 39:
+      return ADC1_CHANNEL_3;
+    case 32:
+      return ADC1_CHANNEL_4;
+    case 33:
+      return ADC1_CHANNEL_5;
+    case 34:
+      return ADC1_CHANNEL_6;
+    case 35:
+      return ADC1_CHANNEL_7;
+    default:
+      return ADC1_CHANNEL_MAX;
+  }
+}
 #endif
 
 void ADCSensor::setup() {
@@ -21,7 +44,9 @@ void ADCSensor::setup() {
 #endif
 
 #ifdef ARDUINO_ARCH_ESP32
-  analogSetPinAttenuation(this->pin_, this->attenuation_);
+  adc1_config_channel_atten(gpio_to_adc1(pin_), attenuation_);
+  adc1_config_width(ADC_WIDTH_BIT_12);
+  adc_gpio_init(ADC_UNIT_1, (adc_channel_t) gpio_to_adc1(pin_));
 #endif
 }
 void ADCSensor::dump_config() {
@@ -36,18 +61,20 @@ void ADCSensor::dump_config() {
 #ifdef ARDUINO_ARCH_ESP32
   ESP_LOGCONFIG(TAG, "  Pin: %u", this->pin_);
   switch (this->attenuation_) {
-    case ADC_0db:
+    case ADC_ATTEN_DB_0:
       ESP_LOGCONFIG(TAG, " Attenuation: 0db (max 1.1V)");
       break;
-    case ADC_2_5db:
+    case ADC_ATTEN_DB_2_5:
       ESP_LOGCONFIG(TAG, " Attenuation: 2.5db (max 1.5V)");
       break;
-    case ADC_6db:
+    case ADC_ATTEN_DB_6:
       ESP_LOGCONFIG(TAG, " Attenuation: 6db (max 2.2V)");
       break;
-    case ADC_11db:
+    case ADC_ATTEN_DB_11:
       ESP_LOGCONFIG(TAG, " Attenuation: 11db (max 3.9V)");
       break;
+    default:  // This is to satisfy the unused ADC_ATTEN_MAX
+      break;
   }
 #endif
   LOG_UPDATE_INTERVAL(this);
@@ -60,20 +87,23 @@ void ADCSensor::update() {
 }
 float ADCSensor::sample() {
 #ifdef ARDUINO_ARCH_ESP32
-  float value_v = analogRead(this->pin_) / 4095.0f;  // NOLINT
+  int raw = adc1_get_raw(gpio_to_adc1(pin_));
+  float value_v = raw / 4095.0f;
   switch (this->attenuation_) {
-    case ADC_0db:
+    case ADC_ATTEN_DB_0:
       value_v *= 1.1;
       break;
-    case ADC_2_5db:
+    case ADC_ATTEN_DB_2_5:
       value_v *= 1.5;
       break;
-    case ADC_6db:
+    case ADC_ATTEN_DB_6:
       value_v *= 2.2;
       break;
-    case ADC_11db:
+    case ADC_ATTEN_DB_11:
       value_v *= 3.9;
       break;
+    default:  // This is to satisfy the unused ADC_ATTEN_MAX
+      break;
   }
   return value_v;
 #endif
diff --git a/esphome/components/adc/adc_sensor.h b/esphome/components/adc/adc_sensor.h
index 3a08ff6be4..4591ed758d 100644
--- a/esphome/components/adc/adc_sensor.h
+++ b/esphome/components/adc/adc_sensor.h
@@ -6,6 +6,10 @@
 #include "esphome/components/sensor/sensor.h"
 #include "esphome/components/voltage_sampler/voltage_sampler.h"
 
+#ifdef ARDUINO_ARCH_ESP32
+#include "driver/adc.h"
+#endif
+
 namespace esphome {
 namespace adc {
 
@@ -13,7 +17,7 @@ class ADCSensor : public sensor::Sensor, public PollingComponent, public voltage
  public:
 #ifdef ARDUINO_ARCH_ESP32
   /// Set the attenuation for this pin. Only available on the ESP32.
-  void set_attenuation(adc_attenuation_t attenuation);
+  void set_attenuation(adc_atten_t attenuation);
 #endif
 
   /// Update adc values.
@@ -34,7 +38,7 @@ class ADCSensor : public sensor::Sensor, public PollingComponent, public voltage
   uint8_t pin_;
 
 #ifdef ARDUINO_ARCH_ESP32
-  adc_attenuation_t attenuation_{ADC_0db};
+  adc_atten_t attenuation_{ADC_ATTEN_DB_0};
 #endif
 };
 
diff --git a/esphome/components/adc/sensor.py b/esphome/components/adc/sensor.py
index 90561679b7..7a944a7260 100644
--- a/esphome/components/adc/sensor.py
+++ b/esphome/components/adc/sensor.py
@@ -16,10 +16,10 @@ from esphome.const import (
 AUTO_LOAD = ["voltage_sampler"]
 
 ATTENUATION_MODES = {
-    "0db": cg.global_ns.ADC_0db,
-    "2.5db": cg.global_ns.ADC_2_5db,
-    "6db": cg.global_ns.ADC_6db,
-    "11db": cg.global_ns.ADC_11db,
+    "0db": cg.global_ns.ADC_ATTEN_DB_0,
+    "2.5db": cg.global_ns.ADC_ATTEN_DB_2_5,
+    "6db": cg.global_ns.ADC_ATTEN_DB_6,
+    "11db": cg.global_ns.ADC_ATTEN_DB_11,
 }