From 6a787b415596c522aaa9165dcc22a2af4b67a395 Mon Sep 17 00:00:00 2001
From: wolfv6 <wolfv6@users.noreply.github.com>
Date: Tue, 15 Nov 2016 20:01:42 -0700
Subject: [PATCH] add LED_PortOpenDrain

---
 examples/keybrd_MCP23018/keybrd_MCP23018.ino |  4 +--
 src/LED_Port.h                               |  5 ++-
 src/LED_PortOpenDrain.cpp                    | 12 +++++++
 src/LED_PortOpenDrain.h                      | 36 ++++++++++++++++++++
 4 files changed, 54 insertions(+), 3 deletions(-)
 create mode 100644 src/LED_PortOpenDrain.cpp
 create mode 100644 src/LED_PortOpenDrain.h

diff --git a/examples/keybrd_MCP23018/keybrd_MCP23018.ino b/examples/keybrd_MCP23018/keybrd_MCP23018.ino
index 2dabd8e..b108ae5 100644
--- a/examples/keybrd_MCP23018/keybrd_MCP23018.ino
+++ b/examples/keybrd_MCP23018/keybrd_MCP23018.ino
@@ -39,7 +39,7 @@ DESTINATION  PIN PIN_NUMBER  PIN    DESTINATION
 //right matrix
 #include <Port_MCP23018.h>
 #include <Scanner_IOE.h>
-#include <LED_Port.h>
+#include <LED_PortOpenDrain.h>
 
 // ============ SPEED CONFIGURATION ============
 ScanDelay scanDelay(9000);
@@ -60,7 +60,7 @@ Port_MCP23018 portB(IOE_ADDR, 1, 0);
 Scanner_IOE scanner_R(LOW, portB, portA);
 
 // ================= RIGHT LED =================
-LED_Port LED_capsLck(portA, 1<<7);
+LED_PortOpenDrain LED_capsLck(portA, 1<<7);
 
 // =================== CODES ===================
 Code_Sc s_a(KEY_A);
diff --git a/src/LED_Port.h b/src/LED_Port.h
index d1d49d5..cbf48f2 100644
--- a/src/LED_Port.h
+++ b/src/LED_Port.h
@@ -5,9 +5,12 @@
 #include <LEDInterface.h>
 #include <PortWriteInterface.h>
 
-/* An LED_Port object is an I/O expander pin that is connected to an LED indicator light.
+/* An LED_Port object is an I/O expander output pin that is connected to an LED indicator light.
 LED_Port functions turn LED on and off.
 
+This is for push-pull ouput pins.
+For LEDs connected to open drain output types, use LED_Port class.
+
 Example initialization:
     const uint8_t IOE_ADDR = 0x20;
     Port_MCP23S17 portA(IOE_ADDR, 0, 1<<0 | 1<<1 );
diff --git a/src/LED_PortOpenDrain.cpp b/src/LED_PortOpenDrain.cpp
new file mode 100644
index 0000000..36a3abb
--- /dev/null
+++ b/src/LED_PortOpenDrain.cpp
@@ -0,0 +1,12 @@
+#include "LED_PortOpenDrain.h"
+/* functions are like LED_Port, but writeLow() writeHigh() are swapped.
+*/
+void LED_PortOpenDrain::on()
+{
+    refPort.writeLow(pin);
+}
+
+void LED_PortOpenDrain::off()
+{
+    refPort.writeHigh(pin);
+}
diff --git a/src/LED_PortOpenDrain.h b/src/LED_PortOpenDrain.h
new file mode 100644
index 0000000..2887db5
--- /dev/null
+++ b/src/LED_PortOpenDrain.h
@@ -0,0 +1,36 @@
+#ifndef LED_PORT_H
+#define LED_PORT_H
+#include <Arduino.h>
+#include <inttypes.h>
+#include <LEDInterface.h>
+#include <PortWriteInterface.h>
+
+/* An LED_PortOpenDrain object is an I/O expander ouput pin that is connected to an LED.
+LED_PortOpenDrain functions turn LED on and off.
+
+This is for open drain ouput pins.
+For LEDs connected to push-pull output types, use LED_Port class.
+
+Example initialization:
+    const uint8_t IOE_ADDR = 0x20;
+    Port_MCP23S17 portA(IOE_ADDR, 0, 1<<0 | 1<<1 );
+    LED_PortOpenDrain LED_fn(portA, 1<<5);
+
+Example initialization:
+    Port_ShiftRegs shiftRegs(8);
+    LED_PortOpenDrain LED_fn(shiftRegs, 1<<6);
+    
+*/
+class LED_PortOpenDrain : public LEDInterface
+{
+    private:
+        PortWriteInterface& refPort;
+        const uint8_t pin;                      //bit pattern, 1 is pin connected to LED
+
+    public:
+        LED_PortOpenDrain(PortWriteInterface& refPort, const uint8_t pin)
+            : refPort(refPort), pin(pin) {}
+        virtual void on();
+        virtual void off();
+};
+#endif