1 files changed, 66 insertions, 0 deletions
diff --git a/movement/lib/morsecalc/mc.c b/movement/lib/morsecalc/mc.c
new file mode 100644
index 00000000..94f6511b
--- /dev/null
+++ b/movement/lib/morsecalc/mc.c
@@ -0,0 +1,66 @@
+/*
+ * MIT License
+ *
+ * Copyright (c) 2023 Christian Chapman
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+
+#include <string.h>
+#include "mc.h"
+
+/* mc_reset Initialize or reset an MC buffer
+ * Input: mc = location of buffer to reset
+ */
+void mc_reset(mc_state_t * mc) {
+    memset(mc->b, '\0', BUFFLEN*sizeof(mc->b[0]));
+    mc->bidx = 0;
+    return;
+   return;
+}
+
+/* mc_input Read an input into a morse code buffer 
+ * Input: mc = buffer to read into
+ *        c = character to read into buffer ('.' or '-', ignored otherwise).
+ * If the buffer is full, reset it instead of entering the new character.
+ */
+void mc_input(mc_state_t * mc, char c) {
+    if(mc->bidx >= BUFFLEN) mc_reset(mc);
+    else if( ('.' == c) || ('-' == c) ) {
+        mc->b[mc->bidx] = c;
+        mc->bidx++;
+    }
+    return;
+}
+
+/* mc_dec Decode a Morse code character (descend MC_DEC_KEY[])
+ * Input: b = BUFFLEN-length char array with '.'s and '-'s
+ * Output: c = Character b represents, or '\0' if not a Morse code. 
+ */
+char mc_dec(char b[BUFFLEN]) {
+    uint8_t pos = 1; // Binary tree position ('.'=0; '-'=1)
+    for(uint8_t idx=0; idx<BUFFLEN; idx++) {
+        if('.' == b[idx]) pos = 2*pos; // Descend in . direction
+        else if('-' == b[idx]) pos = 2*pos+1; // Descend in - direction
+        else break; // End of morse code segment; finished descending
+    }
+    return MC_DEC_KEY[pos-1];
+}
+