From 9f8ad3372382536275926cd95d5e5343235faf21 Mon Sep 17 00:00:00 2001
From: Michael Mandl <mandlm@molez.net>
Date: Sun, 19 Feb 2017 12:17:54 +0100
Subject: [PATCH] Added a 74HC595 shift register

A abstract base class for 74HC595 shift registers without reset and
output-enable functionality.
---
 ShiftRegister.cpp | 27 +++++++++++++++++++++++++++
 ShiftRegister.h   | 18 ++++++++++++++++++
 2 files changed, 45 insertions(+)
 create mode 100644 ShiftRegister.cpp
 create mode 100644 ShiftRegister.h

diff --git a/ShiftRegister.cpp b/ShiftRegister.cpp
new file mode 100644
index 0000000..2294df0
--- /dev/null
+++ b/ShiftRegister.cpp
@@ -0,0 +1,27 @@
+#include "ShiftRegister.h"
+
+void ShiftRegister::set(uint8_t value)
+{
+	for (uint8_t bit = 0; bit < 8; ++bit)
+	{
+		setSerialPin(value & (1 << (7 - bit)));
+		pulseShiftPin();
+	}
+
+	pulseStoragePin();
+}
+
+void ShiftRegister::pulseShiftPin()
+{
+	setShiftPin(false);
+	setShiftPin(true);
+	setShiftPin(false);
+}
+
+void ShiftRegister::pulseStoragePin()
+{
+	setStoragePin(false);
+	setStoragePin(true);
+	setStoragePin(false);
+}
+
diff --git a/ShiftRegister.h b/ShiftRegister.h
new file mode 100644
index 0000000..f9a8e5f
--- /dev/null
+++ b/ShiftRegister.h
@@ -0,0 +1,18 @@
+#pragma once
+
+#include <stdint.h>
+
+class ShiftRegister
+{
+	public:
+		void set(uint8_t value);
+
+	private:
+		virtual void setSerialPin(bool value) = 0;
+		virtual void setShiftPin(bool value) = 0;
+		virtual void setStoragePin(bool value) = 0;
+
+		void pulseShiftPin();
+		void pulseStoragePin();
+};
+