From 04f72f2bb573baef69283e8d5fd5b8205dd0baf6 Mon Sep 17 00:00:00 2001
From: Jonas Zeunert <zeunert@rhrk.uni-kl.de>
Date: Thu, 9 Jan 2020 20:26:31 +0100
Subject: [PATCH] reworked mcp initialization

---
 FlippR-Driver/src/PinController.cpp | 11 +++++++++++
 FlippR-Driver/src/PinController.h   |  2 ++
 2 files changed, 13 insertions(+)

diff --git a/FlippR-Driver/src/PinController.cpp b/FlippR-Driver/src/PinController.cpp
index 0b2f845..f122399 100644
--- a/FlippR-Driver/src/PinController.cpp
+++ b/FlippR-Driver/src/PinController.cpp
@@ -50,6 +50,17 @@ bool PinController::read_pin(uint8_t address)
 
 void PinController::initialize_port_expander(const uint8_t i2c_address, const uint8_t pin_base)
 {
+  auto initialized_port_extender = this->initialized_port_extenders.insert(std::pair<uint8_t, uint8_t>(i2c_address, pin_base);
+  if(initialized_port_extender->second)
+  {
+    if(initialized_port_extender->first->second != pin_base)
+    {
+      CLOG(ERROR, OUTPUT_LOGGER) << "Port extender with address " << i2c_address
+                                 << " is already initialized with pin base " << pin_base;
+    }
+    return;
+  }
+
   mcp23017Setup(pin_base, i2c_address);
   char hex_string[4];
   sprintf(hex_string, "%X", i2c_address);
diff --git a/FlippR-Driver/src/PinController.h b/FlippR-Driver/src/PinController.h
index 13781fa..f1aa4cc 100644
--- a/FlippR-Driver/src/PinController.h
+++ b/FlippR-Driver/src/PinController.h
@@ -39,6 +39,8 @@ public:
   static std::once_flag GPIO_LIB_INITIALIZED;
 
   static std::mutex lock;
+
+  std::map<uint8_t, uint8_t> initialized_port_extenders;
 };
 
 }