diff --git a/companion/src/firmwares/eepromimportexport.h b/companion/src/firmwares/eepromimportexport.h
index 69944cba7..30cd2a045 100644
--- a/companion/src/firmwares/eepromimportexport.h
+++ b/companion/src/firmwares/eepromimportexport.h
@@ -387,7 +387,7 @@ class CharField: public DataField {
 };
 
 static const char specialCharsTab[] = "_-.,";
-static inline int8_t char2idx(char c)
+static inline int8_t char2zchar(char c)
 {
   if (c==' ') return 0;
   if (c>='A' && c<='Z') return 1+c-'A';
@@ -401,7 +401,7 @@ static inline int8_t char2idx(char c)
 }
 
 #define ZCHAR_MAX 40
-static inline char idx2char(int8_t idx)
+static inline char zchar2char(int8_t idx)
 {
   if (idx == 0) return ' ';
   if (idx < 0) {
@@ -429,7 +429,7 @@ class ZCharField: public DataField {
       int b = 0;
       int len = strlen(field);
       for (int i=0; i<N; i++) {
-        int idx = i>=len ? 0 : char2idx(field[i]);
+        int idx = i>=len ? 0 : char2zchar(field[i]);
         for (int j=0; j<8; j++, b++) {
           if (idx & (1<<j))
             output.setBit(b);
@@ -446,7 +446,7 @@ class ZCharField: public DataField {
           if (input[b++])
             idx |= (1<<j);
         }
-        field[i] = idx2char(idx);
+        field[i] = zchar2char(idx);
       }
 
       field[N] = '\0';
diff --git a/radio/src/bluetooth.cpp b/radio/src/bluetooth.cpp
index 476aeba38..72649950b 100644
--- a/radio/src/bluetooth.cpp
+++ b/radio/src/bluetooth.cpp
@@ -401,7 +401,7 @@ void bluetoothWakeup()
       uint8_t len = ZLEN(g_eeGeneral.bluetoothName);
       if (len > 0) {
         for (int i = 0; i < len; i++) {
-          *cur++ = idx2char(g_eeGeneral.bluetoothName[i]);
+          *cur++ = zchar2char(g_eeGeneral.bluetoothName[i]);
         }
       }
       else {
diff --git a/radio/src/gui/128x64/lcd.cpp b/radio/src/gui/128x64/lcd.cpp
index a9be302f3..d800521df 100644
--- a/radio/src/gui/128x64/lcd.cpp
+++ b/radio/src/gui/128x64/lcd.cpp
@@ -292,7 +292,7 @@ uint8_t getTextWidth(const char * s, uint8_t len, LcdFlags flags)
 {
   uint8_t width = 0;
   for (int i=0; len==0 || i<len; ++i) {
-    unsigned char c = (flags & ZCHAR) ? idx2char(*s) : *s;
+    unsigned char c = (flags & ZCHAR) ? zchar2char(*s) : *s;
     if (!c) {
       break;
     }
@@ -327,7 +327,7 @@ void lcdDrawSizedText(coord_t x, coord_t y, const char * s, uint8_t len, LcdFlag
         break;
 #if !defined(BOOT)
       case ZCHAR:
-        c = idx2char(*s);
+        c = zchar2char(*s);
         break;
 #endif
       default:
diff --git a/radio/src/gui/480x272/menu_model.cpp b/radio/src/gui/480x272/menu_model.cpp
index 100904fcf..f751b2bf2 100644
--- a/radio/src/gui/480x272/menu_model.cpp
+++ b/radio/src/gui/480x272/menu_model.cpp
@@ -82,7 +82,7 @@ void editName(coord_t x, coord_t y, char * name, uint8_t size, event_t event, ui
     if (s_editMode > 0) {
       int8_t c = name[editNameCursorPos];
       if (!(flags & ZCHAR)) {
-        c = char2idx(c);
+        c = char2zchar(c);
       }
       int8_t v = c;
 
@@ -132,7 +132,7 @@ void editName(coord_t x, coord_t y, char * name, uint8_t size, event_t event, ui
       if (c != v) {
         if (!(flags & ZCHAR)) {
           if (v != '\0' || name[editNameCursorPos+1] != '\0')
-            v = idx2char(v);
+            v = zchar2char(v);
         }
         name[editNameCursorPos] = v;
         storageDirty(menuVerticalPositions[0] == 0 ? EE_MODEL : EE_GENERAL);
@@ -140,7 +140,7 @@ void editName(coord_t x, coord_t y, char * name, uint8_t size, event_t event, ui
 
       lcdDrawSizedText(x, y, name, size, flags);
       coord_t left = (editNameCursorPos == 0 ? 0 : getTextWidth(name, editNameCursorPos, flags));
-      char s[] = { (flags & ZCHAR) ? idx2char(name[editNameCursorPos]) : name[editNameCursorPos], '\0' };
+      char s[] = { (flags & ZCHAR) ? zchar2char(name[editNameCursorPos]) : name[editNameCursorPos], '\0' };
       lcdDrawSolidFilledRect(x+left-1, y, getTextWidth(s, 1)+1, INVERT_LINE_HEIGHT, TEXT_INVERTED_BGCOLOR);
       lcdDrawText(x+left, y, s, TEXT_INVERTED_COLOR);
     }
diff --git a/radio/src/gui/common/stdlcd/widgets.cpp b/radio/src/gui/common/stdlcd/widgets.cpp
index c1b60ec32..fde626ecd 100644
--- a/radio/src/gui/common/stdlcd/widgets.cpp
+++ b/radio/src/gui/common/stdlcd/widgets.cpp
@@ -160,7 +160,7 @@ void editName(coord_t x, coord_t y, char * name, uint8_t size, event_t event, ui
       }
       
       if (attr == ZCHAR) {
-        lcdDrawChar(x+editNameCursorPos*FW, y, idx2char(v), ERASEBG|INVERS|FIXEDWIDTH);
+        lcdDrawChar(x+editNameCursorPos*FW, y, zchar2char(v), ERASEBG|INVERS|FIXEDWIDTH);
       }
       else {
         lcdDrawChar(x+editNameCursorPos*FW, y, v, ERASEBG|INVERS|FIXEDWIDTH);
diff --git a/radio/src/logs.cpp b/radio/src/logs.cpp
index 63c6ddb46..8a90c71c1 100644
--- a/radio/src/logs.cpp
+++ b/radio/src/logs.cpp
@@ -71,7 +71,7 @@ const char * logsOpen()
       len = i+1;
     if (len) {
       if (filename[i])
-        filename[i] = idx2char(filename[i]);
+        filename[i] = zchar2char(filename[i]);
       else
         filename[i] = '_';
     }
diff --git a/radio/src/opentx.cpp b/radio/src/opentx.cpp
index 9ee271d63..4b416ac11 100644
--- a/radio/src/opentx.cpp
+++ b/radio/src/opentx.cpp
@@ -341,7 +341,7 @@ void defaultInputs()
     }
 #else
     for (int c=0; c<3; c++) {
-      g_model.inputNames[i][c] = char2idx(STR_VSRCRAW[2+4*stick_index+c]);
+      g_model.inputNames[i][c] = char2zchar(STR_VSRCRAW[2 + 4 * stick_index + c]);
     }
 #if LEN_INPUT_NAME > 3
     g_model.inputNames[i][3] = '\0';
diff --git a/radio/src/opentx.h b/radio/src/opentx.h
index 47336de39..bc7a7e90e 100644
--- a/radio/src/opentx.h
+++ b/radio/src/opentx.h
@@ -431,8 +431,8 @@ extern struct t_inactivity inactivity;
 #endif
 
 char hex2zchar(uint8_t hex);
-char idx2char(int8_t idx);
-int8_t char2idx(char c);
+char zchar2char(int8_t idx);
+int8_t char2zchar(char c);
 void str2zchar(char *dest, const char *src, int size);
 int zchar2str(char *dest, const char *src, int size);
 
diff --git a/radio/src/storage/eeprom_rlc.cpp b/radio/src/storage/eeprom_rlc.cpp
index 07c5df730..d3b94d723 100644
--- a/radio/src/storage/eeprom_rlc.cpp
+++ b/radio/src/storage/eeprom_rlc.cpp
@@ -467,7 +467,7 @@ const char * eeBackupModel(uint8_t i_fileSrc)
       len = i+1;
     if (len) {
       if (buf[i])
-        buf[i] = idx2char(buf[i]);
+        buf[i] = zchar2char(buf[i]);
       else
         buf[i] = '_';
     }
diff --git a/radio/src/strhelpers.cpp b/radio/src/strhelpers.cpp
index 99a61996a..313775460 100644
--- a/radio/src/strhelpers.cpp
+++ b/radio/src/strhelpers.cpp
@@ -28,7 +28,7 @@ char hex2zchar(uint8_t hex)
   return (hex >= 10 ? hex-9 : 27+hex);
 }
 
-char idx2char(int8_t idx)
+char zchar2char(int8_t idx)
 {
   if (idx == 0) return ' ';
   if (idx < 0) {
@@ -44,7 +44,7 @@ char idx2char(int8_t idx)
   return ' ';
 }
 
-int8_t char2idx(char c)
+int8_t char2zchar(char c)
 {
   if (c == '_') return 37;
 #if LEN_SPECIAL_CHARS > 0
@@ -63,14 +63,14 @@ void str2zchar(char * dest, const char * src, int size)
 {
   memset(dest, 0, size);
   for (int c=0; c<size && src[c]; c++) {
-    dest[c] = char2idx(src[c]);
+    dest[c] = char2zchar(src[c]);
   }
 }
 
 int zchar2str(char * dest, const char * src, int size)
 {
   for (int c=0; c<size; c++) {
-    dest[c] = idx2char(src[c]);
+    dest[c] = zchar2char(src[c]);
   }
   do {
     dest[size--] = '\0';
@@ -122,7 +122,7 @@ char * strcat_zchar(char * dest, const char * name, uint8_t size, const char * d
         len = i+1;
       if (len) {
         if (dest[i])
-          dest[i] = idx2char(dest[i]);
+          dest[i] = zchar2char(dest[i]);
         else
           dest[i] = '_';
       }