shiftin/shiftout

cores/esp32/wiring_shift.c

@@ -0,0 +1,57 @@
+/*
+ wiring_shift.c - shiftOut() function
+ Part of Arduino - http://www.arduino.cc/
+
+ Copyright (c) 2005-2006 David A. Mellis
+
+ Note: file renamed with a core_esp8266_ prefix to simplify linker
+ script rules for moving code into irom0_text section.
+
+ This library 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 2.1 of the License, or (at your option) any later version.
+
+ This library 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 this library; if not, write to the
+ Free Software Foundation, Inc., 59 Temple Place, Suite 330,
+ Boston, MA  02111-1307  USA
+
+ $Id: wiring.c 248 2007-02-03 15:36:30Z mellis $
+ */
+
+#include "wiring_private.h"
+
+uint8_t shiftIn(uint8_t dataPin, uint8_t clockPin, uint8_t bitOrder) {
+    uint8_t value = 0;
+    uint8_t i;
+
+    for(i = 0; i < 8; ++i) {
+        digitalWrite(clockPin, HIGH);
+        if(bitOrder == LSBFIRST)
+            value |= digitalRead(dataPin) << i;
+        else
+            value |= digitalRead(dataPin) << (7 - i);
+        digitalWrite(clockPin, LOW);
+    }
+    return value;
+}
+
+void shiftOut(uint8_t dataPin, uint8_t clockPin, uint8_t bitOrder, uint8_t val) {
+    uint8_t i;
+
+    for(i = 0; i < 8; i++) {
+        if(bitOrder == LSBFIRST)
+            digitalWrite(dataPin, !!(val & (1 << i)));
+        else
+            digitalWrite(dataPin, !!(val & (1 << (7 - i))));
+
+        digitalWrite(clockPin, HIGH);
+        digitalWrite(clockPin, LOW);
+    }
+}