From aea0c90b3e4c1de1ac3dfba2cd549916f8678355 Mon Sep 17 00:00:00 2001
From: Otto Winter <otto@otto-winter.com>
Date: Fri, 10 May 2019 15:02:59 +0200
Subject: [PATCH] Fix ADC VCC

Fixes https://github.com/esphome/issues/issues/289

Was a linker problem, the macro needs to be defined in global C++ scope (no namespace, not in extern "C" block)
---
 esphome/components/adc/adc_sensor.cpp | 4 ++++
 esphome/components/adc/adc_sensor.h   | 5 +----
 2 files changed, 5 insertions(+), 4 deletions(-)

diff --git a/esphome/components/adc/adc_sensor.cpp b/esphome/components/adc/adc_sensor.cpp
index aef952f27b..d0cea53d49 100644
--- a/esphome/components/adc/adc_sensor.cpp
+++ b/esphome/components/adc/adc_sensor.cpp
@@ -1,6 +1,10 @@
 #include "esphome/components/adc/adc_sensor.h"
 #include "esphome/core/log.h"
 
+#ifdef USE_ADC_SENSOR_VCC
+ADC_MODE(ADC_VCC)
+#endif
+
 namespace esphome {
 namespace adc {
 
diff --git a/esphome/components/adc/adc_sensor.h b/esphome/components/adc/adc_sensor.h
index 7d26a67ae4..3a08ff6be4 100644
--- a/esphome/components/adc/adc_sensor.h
+++ b/esphome/components/adc/adc_sensor.h
@@ -2,16 +2,13 @@
 
 #include "esphome/core/component.h"
 #include "esphome/core/esphal.h"
+#include "esphome/core/defines.h"
 #include "esphome/components/sensor/sensor.h"
 #include "esphome/components/voltage_sampler/voltage_sampler.h"
 
 namespace esphome {
 namespace adc {
 
-#ifdef USE_ADC_SENSOR_VCC
-ADC_MODE(ADC_VCC)
-#endif
-
 class ADCSensor : public sensor::Sensor, public PollingComponent, public voltage_sampler::VoltageSampler {
  public:
 #ifdef ARDUINO_ARCH_ESP32