From 4a379ec085c6a9ef400839e99c9af885830899e0 Mon Sep 17 00:00:00 2001
From: Gordon Henderson <projects@drogon.net>
Date: Thu, 27 Jun 2013 21:52:42 +0100
Subject: [PATCH] Properly added the max31855 files now

---
 wiringPi/max31855.c | 81 +++++++++++++++++++++++++++++++++++++++++++++++++++++
 wiringPi/max31855.h | 33 ++++++++++++++++++++++
 2 files changed, 114 insertions(+)
 create mode 100644 wiringPi/max31855.c
 create mode 100644 wiringPi/max31855.h

diff --git a/wiringPi/max31855.c b/wiringPi/max31855.c
new file mode 100644
index 0000000..2185839
--- /dev/null
+++ b/wiringPi/max31855.c
@@ -0,0 +1,81 @@
+/*
+ * max31855.c:
+ *	Extend wiringPi with the max31855 SPI Analog to Digital convertor
+ *	Copyright (c) 2012-2013 Gordon Henderson
+ ***********************************************************************
+ * This file is part of wiringPi:
+ *	https://projects.drogon.net/raspberry-pi/wiringpi/
+ *
+ *    wiringPi is free software: you can redistribute it and/or modify
+ *    it under the terms of the GNU Lesser General Public License as
+ *    published by the Free Software Foundation, either version 3 of the
+ *    License, or (at your option) any later version.
+ *
+ *    wiringPi is distributed in the hope that it will be useful,
+ *    but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *    GNU Lesser General Public License for more details.
+ *
+ *    You should have received a copy of the GNU Lesser General Public
+ *    License along with wiringPi.
+ *    If not, see <http://www.gnu.org/licenses/>.
+ ***********************************************************************
+ */
+
+#include <wiringPi.h>
+#include <wiringPiSPI.h>
+
+#include "max31855.h"
+
+/*
+ * myAnalogRead:
+ *	Return the analog value of the given pin
+ *	Note: The chip really only has one read "channel", but we're faking it
+ *	here so we can read the error registers. Channel 0 will be the data
+ *	channel, and 1 is the error register code.
+ *	Note: Temperature returned is temp in C * 4, so divide result by 4
+ *********************************************************************************
+ */
+
+static int myAnalogRead (struct wiringPiNodeStruct *node, int pin)
+{
+  unsigned int spiData ;
+  int temp ;
+  int chan = pin - node->pinBase ;
+
+  wiringPiSPIDataRW (node->fd, (unsigned char *)&spiData, 4) ;
+
+  if (chan == 0)			// Read temp in C
+  {
+    spiData >>= 18 ;
+    temp = spiData & 0x3FFF ;		// Bottom 13 bits
+    if ((spiData & 0x2000) != 0)	// Negative
+      temp = -temp ;
+    return temp ;
+  }
+  else					// Return error bits
+    return spiData & 0x7 ;
+}
+
+
+/*
+ * max31855Setup:
+ *	Create a new wiringPi device node for an max31855 on the Pi's
+ *	SPI interface.
+ *********************************************************************************
+ */
+
+int max31855Setup (const int pinBase, int spiChannel)
+{
+  struct wiringPiNodeStruct *node ;
+
+  if (wiringPiSPISetup (spiChannel, 5000000) < 0)	// 5MHz - prob 4 on the Pi
+    return -1 ;
+
+  node = wiringPiNewNode (pinBase, 2) ;
+
+  node->fd         = spiChannel ;
+  node->analogRead = myAnalogRead ;
+
+  return 0 ;
+}
diff --git a/wiringPi/max31855.h b/wiringPi/max31855.h
new file mode 100644
index 0000000..385c4bd
--- /dev/null
+++ b/wiringPi/max31855.h
@@ -0,0 +1,33 @@
+/*
+ * max31855.c:
+ *	Extend wiringPi with the MAX31855 SPI Thermocouple driver
+ *	Copyright (c) 2012-2013 Gordon Henderson
+ ***********************************************************************
+ * This file is part of wiringPi:
+ *	https://projects.drogon.net/raspberry-pi/wiringpi/
+ *
+ *    wiringPi is free software: you can redistribute it and/or modify
+ *    it under the terms of the GNU Lesser General Public License as
+ *    published by the Free Software Foundation, either version 3 of the
+ *    License, or (at your option) any later version.
+ *
+ *    wiringPi is distributed in the hope that it will be useful,
+ *    but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *    GNU Lesser General Public License for more details.
+ *
+ *    You should have received a copy of the GNU Lesser General Public
+ *    License along with wiringPi.
+ *    If not, see <http://www.gnu.org/licenses/>.
+ ***********************************************************************
+ */
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+extern int max31855Setup (int pinBase, int spiChannel) ;
+
+#ifdef __cplusplus
+}
+#endif