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authorCristian Maglie <c.maglie@bug.st>2013-06-01 23:16:02 +0200
committerCristian Maglie <c.maglie@bug.st>2013-06-01 23:16:02 +0200
commit177ad96f866714a4962be57f69cd3d5a6334cde1 (patch)
tree1072239986340d6a239adac924eddf2e1d1ca566 /libraries/Robot_Control/SPI.cpp
parent6cff36ac5e85c74bcb45cc53491ad69d64520b36 (diff)
parentd90fcca5839d13d57ed527d4009b78d22dafbde7 (diff)
Merge branch 'merge-1.0.5' into ide-1.5.x-discovery
Diffstat (limited to 'libraries/Robot_Control/SPI.cpp')
-rw-r--r--libraries/Robot_Control/SPI.cpp66
1 files changed, 66 insertions, 0 deletions
diff --git a/libraries/Robot_Control/SPI.cpp b/libraries/Robot_Control/SPI.cpp
new file mode 100644
index 0000000..5e48073
--- /dev/null
+++ b/libraries/Robot_Control/SPI.cpp
@@ -0,0 +1,66 @@
+/*
+ * Copyright (c) 2010 by Cristian Maglie <c.maglie@bug.st>
+ * SPI Master library for arduino.
+ *
+ * This file is free software; you can redistribute it and/or modify
+ * it under the terms of either the GNU General Public License version 2
+ * or the GNU Lesser General Public License version 2.1, both as
+ * published by the Free Software Foundation.
+ */
+
+#include "pins_arduino.h"
+#include "SPI.h"
+
+SPIClass SPI;
+
+void SPIClass::begin() {
+
+ // Set SS to high so a connected chip will be "deselected" by default
+ digitalWrite(SS, HIGH);
+
+ // When the SS pin is set as OUTPUT, it can be used as
+ // a general purpose output port (it doesn't influence
+ // SPI operations).
+ pinMode(SS, OUTPUT);
+
+ // Warning: if the SS pin ever becomes a LOW INPUT then SPI
+ // automatically switches to Slave, so the data direction of
+ // the SS pin MUST be kept as OUTPUT.
+ SPCR |= _BV(MSTR);
+ SPCR |= _BV(SPE);
+
+ // Set direction register for SCK and MOSI pin.
+ // MISO pin automatically overrides to INPUT.
+ // By doing this AFTER enabling SPI, we avoid accidentally
+ // clocking in a single bit since the lines go directly
+ // from "input" to SPI control.
+ // http://code.google.com/p/arduino/issues/detail?id=888
+ pinMode(SCK, OUTPUT);
+ pinMode(MOSI, OUTPUT);
+}
+
+
+void SPIClass::end() {
+ SPCR &= ~_BV(SPE);
+}
+
+void SPIClass::setBitOrder(uint8_t bitOrder)
+{
+ if(bitOrder == LSBFIRST) {
+ SPCR |= _BV(DORD);
+ } else {
+ SPCR &= ~(_BV(DORD));
+ }
+}
+
+void SPIClass::setDataMode(uint8_t mode)
+{
+ SPCR = (SPCR & ~SPI_MODE_MASK) | mode;
+}
+
+void SPIClass::setClockDivider(uint8_t rate)
+{
+ SPCR = (SPCR & ~SPI_CLOCK_MASK) | (rate & SPI_CLOCK_MASK);
+ SPSR = (SPSR & ~SPI_2XCLOCK_MASK) | ((rate >> 2) & SPI_2XCLOCK_MASK);
+}
+