integer to binary array conversion

api/Binary.cpp

@@ -0,0 +1,37 @@
+/*
+  binary.cpp - Definitions for binary constants
+  Copyright (c) 2025 jsnkan. All right reserved.
+
+  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., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+*/
+
+#include "Binary.h"
+
+void intToBinaryArray(unsigned char n, int *arr) {
+  if (arr == 0) return;
+  for (int i = 7; i >= 0; i--) {
+      arr[i] = n & 1;
+      n >>= 1;
+  }
+}
+
+unsigned char binaryArrayToInt(int *arr) {
+  if (arr == 0) return 0;
+  unsigned char n = 0;
+  for (int i = 0; i < 8; i++) {
+      n = (n << 1) | (arr[i] & 1);
+  }
+  return n;
+}

api/Binary.h

@@ -34,6 +34,9 @@
   #define DEPRECATED(x)
 #endif
 
+void intToBinaryArray(unsigned char n, int *arr);
+unsigned char binaryArrayToInt(int *arr);
+
 enum {
   B0        DEPRECATED(0b0       ) = 0,
   B00       DEPRECATED(0b00      ) = 0,