From 61e44047076b0cb7064793e882bd4f00d15e2c26 Mon Sep 17 00:00:00 2001
From: David Antliff <david@pitchblende.co.nz>
Date: Tue, 7 Apr 2020 12:07:18 +1200
Subject: [PATCH 1/3] Fix CMakeLists.txt for CMake variable changes in ESP-IDF
 v4.1-beta1 and newer.

---
 CMakeLists.txt | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 1e87312..051f8ec 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -6,4 +6,4 @@ include($ENV{IDF_PATH}/tools/cmake/project.cmake)
 project(esp32-ds18b20-example)
 
 # Ignore false clang warnings about `struct foo = { 0 }`
-target_compile_options(${IDF_PROJECT_EXECUTABLE} PRIVATE -Wno-missing-braces -Wmissing-field-initializers)
+target_compile_options(${project_elf} PRIVATE -Wno-missing-braces -Wmissing-field-initializers)

From 5a3f2244052d2390ed2fc2c842ea6c983e0972cb Mon Sep 17 00:00:00 2001
From: David Antliff <david@pitchblende.co.nz>
Date: Tue, 7 Apr 2020 16:58:35 +1200
Subject: [PATCH 2/3] Add CMake logic to support both IDF v3.3 and v4.x.

---
 CMakeLists.txt | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 051f8ec..31da009 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -5,5 +5,15 @@ cmake_minimum_required(VERSION 3.5)
 include($ENV{IDF_PATH}/tools/cmake/project.cmake)
 project(esp32-ds18b20-example)
 
+if (NOT IDF_VERSION_MAJOR)
+  set(IDF_VERSION_MAJOR 3)
+endif()
+
+if (IDF_VERSION_MAJOR GREATER 3)
+  set(PROJECT_ELF ${project_elf})
+else()
+  set(PROJECT_ELF ${IDF_PROJECT_EXECUTABLE})
+endif()
+
 # Ignore false clang warnings about `struct foo = { 0 }`
-target_compile_options(${project_elf} PRIVATE -Wno-missing-braces -Wmissing-field-initializers)
+target_compile_options(${PROJECT_ELF} PRIVATE -Wno-missing-braces -Wmissing-field-initializers)

From 912310eafdd53a269015cba5a3357fe5431285af Mon Sep 17 00:00:00 2001
From: David Antliff <david@pitchblende.co.nz>
Date: Tue, 7 Apr 2020 17:20:27 +1200
Subject: [PATCH 3/3] Add TravisCI support for ESP-IDF v4.1-beta1.

---
 .travis.yml | 58 ++++++++++++++++++++++++++++-------------------------
 1 file changed, 31 insertions(+), 27 deletions(-)

diff --git a/.travis.yml b/.travis.yml
index 4821e4b..397e57e 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -1,33 +1,37 @@
+os: linux
 dist: bionic
 language: python
 python: "3.8"
 
-before_install:
-  # Save path to the git respository
-  - PROJECT_PATH=$(pwd)
+jobs:
+  include:
+    - stage:  # IDF v3.3
+      install:
+        # Install ESP32 toochain following steps as described
+        # in http://esp-idf.readthedocs.io/en/latest/linux-setup.html
+        #
+        # Download binary toolchain for the ESP32
+        - pushd ~
+        - wget https://dl.espressif.com/dl/xtensa-esp32-elf-linux64-1.22.0-80-g6c4433a-5.2.0.tar.gz
+        - tar -xzf xtensa-esp32-elf-linux64-1.22.0-80-g6c4433a-5.2.0.tar.gz
+        # Make xtensa-esp32-elf available for all terminal sessions
+        - export PATH=$PATH:$(pwd)/xtensa-esp32-elf/bin
+        # Get ESP-IDF from github
+        - git clone --recursive --branch v3.3 --single-branch --shallow-submodules https://github.com/espressif/esp-idf.git esp-idf
+        # Set the path to ESP-IDF directory
+        - export IDF_PATH=$(pwd)/esp-idf
+        # Install python dependencies
+        - pip install --requirement $IDF_PATH/requirements.txt
+        - popd
+      script:
+        - $IDF_PATH/tools/idf.py build
 
-install:
-  # Install ESP32 toochain following steps as desribed
-  # in http://esp-idf.readthedocs.io/en/latest/linux-setup.html
-  #
-  # Get required packages - already done above, see addons: apt: packages:
-  # - sudo apt-get install git wget make libncurses-dev flex bison gperf python python-serial
-  # Prepare directory for the toolchain
-  - mkdir -p ~/esp
-  - cd ~/esp
-  # Download binary toolchain for the ESP32
-  - wget https://dl.espressif.com/dl/xtensa-esp32-elf-linux64-1.22.0-80-g6c4433a-5.2.0.tar.gz
-  - tar -xzf xtensa-esp32-elf-linux64-1.22.0-80-g6c4433a-5.2.0.tar.gz
-  # Make xtensa-esp32-elf available for all terminal sessions
-  - export PATH=$PATH:$HOME/esp/xtensa-esp32-elf/bin
-  # Get ESP-IDF from github
-  - git clone --recursive --branch v3.3 --single-branch --shallow-submodules https://github.com/espressif/esp-idf.git
-  # Set the path to ESP-IDF directory
-  - export IDF_PATH=~/esp/esp-idf
-  # Install python dependencies
-  - pip install --requirement $IDF_PATH/requirements.txt
+    - stage:  # IDF v4.1-beta1
+      install:
+        - pushd ~
+        - git clone --recursive --branch v4.1-beta1 --single-branch --shallow-submodules https://github.com/espressif/esp-idf.git esp-idf
+        - esp-idf/install.sh
+        - popd
+      script:
+        - source ~/esp-idf/export.sh && idf.py build
 
-script:
-  # Build project within the original repository
-  - cd $PROJECT_PATH
-  - $IDF_PATH/tools/idf.py build