From 20c8621f0bf867672eae827bf381dc64779bd79b Mon Sep 17 00:00:00 2001
From: 2bndy5 <2bndy5@gmail.com>
Date: Sat, 22 Jan 2022 17:32:49 -0800
Subject: [PATCH] conditionally build examples with pigpio

---
 examples_RPi/CMakeLists.txt | 10 ++++++++--
 examples_RPi/Makefile       | 11 ++++++++++-
 2 files changed, 18 insertions(+), 3 deletions(-)

diff --git a/examples_RPi/CMakeLists.txt b/examples_RPi/CMakeLists.txt
index cbf1ea6d..80ae0c16 100644
--- a/examples_RPi/CMakeLists.txt
+++ b/examples_RPi/CMakeLists.txt
@@ -19,10 +19,16 @@ message(STATUS "using RF24 library: ${RF24}")
 find_library(RF24Network rf24network REQUIRED)
 message(STATUS "using RF24Network library: ${RF24Network}")
 
+find_library(LibPIGPIO pigpio)
+
 foreach(example ${EXAMPLES_LIST})
     # make a target
     add_executable(${example} ${example}.cpp)
-
     # link the RF24 lib to the target. Notice we specify pthread as a linked lib here
-    target_link_libraries(${example} PUBLIC ${RF24} pthread ${RF24Network})
+    if ("${LibPIGPIO}" STREQUAL "LibPIGPIO-NOTFOUND")
+        target_link_libraries(${example} PUBLIC ${RF24} pthread ${RF24Network})
+    else()
+        message(STATUS "linking to ${LibPIGPIO} for interrupt support")
+        target_link_libraries(${example} PUBLIC ${RF24} pthread ${RF24Network} ${LibPIGPIO})
+    endif()
 endforeach()
diff --git a/examples_RPi/Makefile b/examples_RPi/Makefile
index 0b77c460..43522374 100644
--- a/examples_RPi/Makefile
+++ b/examples_RPi/Makefile
@@ -25,11 +25,20 @@ ifneq "${RPI}" "1"
 RPI=$(shell cat /proc/cpuinfo | grep Hardware | grep -c BCM2709)
 endif
 
+pigpio_detected=0
+ifeq ($(wildcard "/usr/lib/libpigpio.so"))
+pigpio_detected=1
+endif
+
 ifeq "$(RPI)" "1"
 # The recommended compiler flags for the Raspberry Pi
 CCFLAGS=-Ofast -mfpu=vfp -mfloat-abi=hard -march=$(ARCH) -mtune=arm1176jzf-s -std=c++0x
+ifeq "$(pigpio_detected)" "1"
+CCFLAGS=$(CCFLAGS) -lpigpio
+endif
+else
+CCFLAGS=$(CCFLAGS) -DRF24_NO_INTERRUPT
 endif
-
 
 # define all programs
 PROGRAMS = rx-test helloworld_rx helloworld_tx