Feature-ify Send String (#17275)

12 files changed, 892 insertions, 623 deletions

diff --git a/builddefs/common_features.mk b/builddefs/common_features.mk
index c11e5688e3..5cc4508307 100644
--- a/builddefs/common_features.mk
+++ b/builddefs/common_features.mk
@@ -15,7 +15,6 @@
 
 QUANTUM_SRC += \
     $(QUANTUM_DIR)/quantum.c \
-    $(QUANTUM_DIR)/send_string.c \
     $(QUANTUM_DIR)/bitwise.c \
     $(QUANTUM_DIR)/led.c \
     $(QUANTUM_DIR)/action.c \
@@ -774,6 +773,13 @@ ifeq ($(strip $(MAGIC_ENABLE)), yes)
     OPT_DEFS += -DMAGIC_KEYCODE_ENABLE
 endif
 
+SEND_STRING_ENABLE ?= yes
+ifeq ($(strip $(SEND_STRING_ENABLE)), yes)
+    OPT_DEFS += -DSEND_STRING_ENABLE
+    COMMON_VPATH += $(QUANTUM_DIR)/send_string
+    SRC += $(QUANTUM_DIR)/send_string/send_string.c
+endif
+
 ifeq ($(strip $(AUTO_SHIFT_ENABLE)), yes)
     SRC += $(QUANTUM_DIR)/process_keycode/process_auto_shift.c
     OPT_DEFS += -DAUTO_SHIFT_ENABLE
diff --git a/docs/_summary.md b/docs/_summary.md
index da007bccb6..b5746ff6de 100644
--- a/docs/_summary.md
+++ b/docs/_summary.md
@@ -84,6 +84,7 @@
     * [One Shot Keys](one_shot_keys.md)
     * [Pointing Device](feature_pointing_device.md)
     * [Raw HID](feature_rawhid.md)
+    * [Send String](feature_send_string.md)
     * [Sequencer](feature_sequencer.md)
     * [Swap Hands](feature_swap_hands.md)
     * [Tap Dance](feature_tap_dance.md)
diff --git a/docs/feature_macros.md b/docs/feature_macros.md
index 78bc4ba0a5..f5b163d5df 100644
--- a/docs/feature_macros.md
+++ b/docs/feature_macros.md
@@ -106,6 +106,8 @@ Only basic keycodes (prefixed by `KC_`) are supported. Do not include the `KC_`
 
 ### `SEND_STRING()` & `process_record_user`
 
+See also: [Send String](feature_send_string.md)
+
 Sometimes you want a key to type out words or phrases. For the most common situations, we've provided `SEND_STRING()`, which will type out a string (i.e. a sequence of characters) for you. All ASCII characters that are easily translatable to a keycode are supported (e.g. `qmk 123\n\t`).
 
 Here is an example `keymap.c` for a two-key keyboard:
diff --git a/docs/feature_send_string.md b/docs/feature_send_string.md
new file mode 100644
index 0000000000..67df0224e9
--- /dev/null
+++ b/docs/feature_send_string.md
@@ -0,0 +1,224 @@
+# Send String
+
+The Send String API is part of QMK's macro system. It allows for sequences of keystrokes to be sent automatically.
+
+The full ASCII character set is supported, along with all of the keycodes in the Basic Keycode range (as these are the only ones that will actually be sent to the host).
+
+?> Unicode characters are **not** supported with this API -- see the [Unicode](feature_unicode.md) feature instead.
+
+## Usage
+
+Send String is enabled by default, so there is usually no need for any special setup. However, if it is disabled, add the following to your `rules.mk`:
+
+```make
+SEND_STRING_ENABLE = yes
+```
+
+## Basic Configuration
+
+Add the following to your `config.h`:
+
+|Define           |Default         |Description                                                                                                 |
+|-----------------|----------------|------------------------------------------------------------------------------------------------------------|
+|`SENDSTRING_BELL`|*Not defined*   |If the [Audio](feature_audio.md) feature is enabled, the `\a` character (ASCII `BEL`) will beep the speaker.|
+|`BELL_SOUND`     |`TERMINAL_SOUND`|The song to play when the `\a` character is encountered. By default, this is an eighth note of C5.          |
+
+## Keycodes
+
+The Send String functions accept C string literals, but specific keycodes can be injected with the below macros. All of the keycodes in the [Basic Keycode range](keycodes_basic.md) are supported (as these are the only ones that will actually be sent to the host), but with an `X_` prefix instead of `KC_`.
+
+|Macro         |Description                                                        |
+|--------------|-------------------------------------------------------------------|
+|`SS_TAP(x)`   |Send a keydown, then keyup, event for the given Send String keycode|
+|`SS_DOWN(x)`  |Send a keydown event for the given Send String keycode             |
+|`SS_UP(x)`    |Send a keyup event for the given Send String keycode               |
+|`SS_DELAY(ms)`|Wait for `ms` milliseconds                                         |
+
+The following characters are also mapped to their respective keycodes for convenience:
+
+|Character|Hex   |ASCII|Keycode       |
+|---------|------|-----|--------------|
+|`\b`     |`\x08`|`BS` |`KC_BACKSPACE`|
+|`\e`     |`\x09`|`ESC`|`KC_ESCAPE`   |
+|`\n`     |`\x0A`|`LF` |`KC_ENTER`    |
+|`\t`     |`\x1B`|`TAB`|`KC_TAB`      |
+|         |`\x7F`|`DEL`|`KC_DELETE`   |
+
+### Language Support
+
+By default, Send String assumes your OS keyboard layout is set to US ANSI. If you are using a different keyboard layout, you can [override the lookup tables used to convert ASCII characters to keystrokes](reference_keymap_extras.md#sendstring-support).
+
+## Examples
+
+### Hello World
+
+A simple custom keycode which types out "Hello, world!" and the Enter key when pressed.
+
+Add the following to your `keymap.c`:
+
+```c
+bool process_record_user(uint16_t keycode, keyrecord_t *record) {
+    switch (keycode) {
+        case SS_HELLO:
+            if (record->event.pressed) {
+                SEND_STRING("Hello, world!\n");
+            }
+            return false;
+    }
+
+    return true;
+}
+```
+
+### Keycode Injection
+
+This example types out opening and closing curly braces, then taps the left arrow key to move the cursor between the two.
+
+```c
+SEND_STRING("{}" SS_TAP(X_LEFT));
+```
+
+This example types Ctrl+A, then Ctrl+C, without releasing Ctrl.
+
+```c
+SEND_STRING(SS_LCTL("ac"));
+```
+
+## API
+
+### `void send_string(const char *string)`
+
+Type out a string of ASCII characters.
+
+This function simply calls `send_string_with_delay(string, 0)`.
+
+#### Arguments
+
+ - `const char *string`  
+   The string to type out.
+
+---
+
+### `void send_string_with_delay(const char *string, uint8_t interval)`
+
+Type out a string of ASCII characters, with a delay between each character.
+
+#### Arguments
+
+ - `const char *string`  
+   The string to type out.
+ - `uint8_t interval`  
+   The amount of time, in milliseconds, to wait before typing the next character.
+
+---
+
+### `void send_string_P(const char *string)`
+
+Type out a PROGMEM string of ASCII characters.
+
+On ARM devices, this function is simply an alias for `send_string_with_delay(string, 0)`.
+
+#### Arguments
+
+ - `const char *string`  
+   The string to type out.
+
+---
+
+### `void send_string_with_delay_P(const char *string, uint8_t interval)`
+
+Type out a PROGMEM string of ASCII characters, with a delay between each character.
+
+On ARM devices, this function is simply an alias for `send_string_with_delay(string, interval)`.
+
+#### Arguments
+
+ - `const char *string`  
+   The string to type out.
+ - `uint8_t interval`  
+   The amount of time, in milliseconds, to wait before typing the next character.
+
+---
+
+### `void send_char(char ascii_code)`
+
+Type out an ASCII character.
+
+#### Arguments
+
+ - `char ascii_code`  
+   The character to type.
+
+---
+
+### `void send_dword(uint32_t number)`
+
+Type out an eight digit (unsigned 32-bit) hexadecimal value.
+
+The format is `[0-9a-f]{8}`, eg. `00000000` through `ffffffff`.
+
+#### Arguments
+
+ - `uint32_t number`  
+   The value to type, from 0 to 4,294,967,295.
+
+---
+
+### `void send_word(uint16_t number)`
+
+Type out a four digit (unsigned 16-bit) hexadecimal value.
+
+The format is `[0-9a-f]{4}`, eg. `0000` through `ffff`.
+
+#### Arguments
+
+ - `uint16_t number`  
+   The value to type, from 0 to 65,535.
+
+---
+
+### `void send_byte(uint8_t number)`
+
+Type out a two digit (8-bit) hexadecimal value.
+
+The format is `[0-9a-f]{2}`, eg. `00` through `ff`.
+
+#### Arguments
+
+ - `uint8_t number`  
+   The value to type, from 0 to 255.
+
+---
+
+### `void send_nibble(uint8_t number)`
+
+Type out a single hexadecimal digit.
+
+The format is `[0-9a-f]{1}`, eg. `0` through `f`.
+
+#### Arguments
+
+ - `uint8_t number`  
+   The value to type, from 0 to 15.
+
+---
+
+### `void tap_random_base64(void)`
+
+Type a pseudorandom character from the set `A-Z`, `a-z`, `0-9`, `+` and `/`.
+
+---
+
+### `SEND_STRING(string)`
+
+Shortcut macro for `send_string_with_delay_P(PSTR(string), 0)`.
+
+On ARM devices, this define evaluates to `send_string_with_delay(string, 0)`.
+
+---
+
+### `SEND_STRING_DELAY(string, interval)`
+
+Shortcut macro for `send_string_with_delay_P(PSTR(string), interval)`.
+
+On ARM devices, this define evaluates to `send_string_with_delay(string, interval)`.
diff --git a/quantum/process_keycode/process_auto_shift.c b/quantum/process_keycode/process_auto_shift.c
index e6a7c01f2a..8cb45bc0ae 100644
--- a/quantum/process_keycode/process_auto_shift.c
+++ b/quantum/process_keycode/process_auto_shift.c
@@ -325,11 +325,13 @@ void autoshift_disable(void) {
 
 #    ifndef AUTO_SHIFT_NO_SETUP
 void autoshift_timer_report(void) {
+#        ifdef SEND_STRING_ENABLE
     char display[8];
 
     snprintf(display, 8, "\n%d\n", autoshift_timeout);
 
     send_string((const char *)display);
+#        endif
 }
 #    endif
 
diff --git a/quantum/process_keycode/process_dynamic_tapping_term.c b/quantum/process_keycode/process_dynamic_tapping_term.c
index bdc5529e33..b682f34da6 100644
--- a/quantum/process_keycode/process_dynamic_tapping_term.c
+++ b/quantum/process_keycode/process_dynamic_tapping_term.c
@@ -22,12 +22,14 @@
 #endif
 
 static void tapping_term_report(void) {
+#ifdef SEND_STRING_ENABLE
     const char *tapping_term_str = get_u16_str(g_tapping_term, ' ');
     // Skip padding spaces
     while (*tapping_term_str == ' ') {
         tapping_term_str++;
     }
     send_string(tapping_term_str);
+#endif
 }
 
 bool process_dynamic_tapping_term(uint16_t keycode, keyrecord_t *record) {
diff --git a/quantum/quantum.h b/quantum/quantum.h
index 8a7a20c706..f3a8a323c7 100644
--- a/quantum/quantum.h
+++ b/quantum/quantum.h
@@ -49,7 +49,6 @@
 #include "action_util.h"
 #include "action_tapping.h"
 #include "print.h"
-#include "send_string.h"
 #include "suspend.h"
 #include <stddef.h>
 #include <stdlib.h>
@@ -169,6 +168,10 @@ extern layer_state_t layer_state;
 #    include "hd44780.h"
 #endif
 
+#ifdef SEND_STRING_ENABLE
+#    include "send_string.h"
+#endif
+
 #ifdef HAPTIC_ENABLE
 #    include "haptic.h"
 #    include "process_haptic.h"
diff --git a/quantum/send_string.h b/quantum/send_string.h
deleted file mode 100644
index b90e6f6890..0000000000
--- a/quantum/send_string.h
+++ /dev/null
@@ -1,54 +0,0 @@
-/* Copyright 2021
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 2 of the License, or
- * (at your option) any later version.
- *
- * This program 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 General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
- */
-
-#include <stdint.h>
-
-#include "progmem.h"
-#include "send_string_keycodes.h"
-
-#define SEND_STRING(string) send_string_P(PSTR(string))
-#define SEND_STRING_DELAY(string, interval) send_string_with_delay_P(PSTR(string), interval)
-
-// Look-Up Tables (LUTs) to convert ASCII character to keycode sequence.
-extern const uint8_t ascii_to_shift_lut[16];
-extern const uint8_t ascii_to_altgr_lut[16];
-extern const uint8_t ascii_to_dead_lut[16];
-extern const uint8_t ascii_to_keycode_lut[128];
-
-// clang-format off
-#define KCLUT_ENTRY(a, b, c, d, e, f, g, h) \
-    ( ((a) ? 1 : 0) << 0 \
-    | ((b) ? 1 : 0) << 1 \
-    | ((c) ? 1 : 0) << 2 \
-    | ((d) ? 1 : 0) << 3 \
-    | ((e) ? 1 : 0) << 4 \
-    | ((f) ? 1 : 0) << 5 \
-    | ((g) ? 1 : 0) << 6 \
-    | ((h) ? 1 : 0) << 7 )
-// clang-format on
-
-void send_string(const char *str);
-void send_string_with_delay(const char *str, uint8_t interval);
-void send_string_P(const char *str);
-void send_string_with_delay_P(const char *str, uint8_t interval);
-void send_char(char ascii_code);
-
-void send_dword(uint32_t number);
-void send_word(uint16_t number);
-void send_byte(uint8_t number);
-void send_nibble(uint8_t number);
-
-void tap_random_base64(void);
diff --git a/quantum/send_string.c b/quantum/send_string/send_string.c
index 0de12ba12d..818a52f6dc 100644
--- a/quantum/send_string.c
+++ b/quantum/send_string/send_string.c
@@ -142,40 +142,36 @@ __attribute__((weak)) const uint8_t ascii_to_keycode_lut[128] PROGMEM = {
 // Note: we bit-pack in "reverse" order to optimize loading
 #define PGM_LOADBIT(mem, pos) ((pgm_read_byte(&((mem)[(pos) / 8])) >> ((pos) % 8)) & 0x01)
 
-void send_string(const char *str) {
-    send_string_with_delay(str, 0);
+void send_string(const char *string) {
+    send_string_with_delay(string, 0);
 }
 
-void send_string_P(const char *str) {
-    send_string_with_delay_P(str, 0);
-}
-
-void send_string_with_delay(const char *str, uint8_t interval) {
+void send_string_with_delay(const char *string, uint8_t interval) {
     while (1) {
-        char ascii_code = *str;
+        char ascii_code = *string;
         if (!ascii_code) break;
         if (ascii_code == SS_QMK_PREFIX) {
-            ascii_code = *(++str);
+            ascii_code = *(++string);
             if (ascii_code == SS_TAP_CODE) {
                 // tap
-                uint8_t keycode = *(++str);
+                uint8_t keycode = *(++string);
                 tap_code(keycode);
             } else if (ascii_code == SS_DOWN_CODE) {
                 // down
-                uint8_t keycode = *(++str);
+                uint8_t keycode = *(++string);
                 register_code(keycode);
             } else if (ascii_code == SS_UP_CODE) {
                 // up
-                uint8_t keycode = *(++str);
+                uint8_t keycode = *(++string);
                 unregister_code(keycode);
             } else if (ascii_code == SS_DELAY_CODE) {
                 // delay
                 int     ms      = 0;
-                uint8_t keycode = *(++str);
+                uint8_t keycode = *(++string);
                 while (isdigit(keycode)) {
                     ms *= 10;
                     ms += keycode - '0';
-                    keycode = *(++str);
+                    keycode = *(++string);
                 }
                 while (ms--)
                     wait_ms(1);
@@ -183,50 +179,7 @@ void send_string_with_delay(const char *str, uint8_t interval) {
         } else {
             send_char(ascii_code);
         }
-        ++str;
-        // interval
-        {
-            uint8_t ms = interval;
-            while (ms--)
-                wait_ms(1);
-        }
-    }
-}
-
-void send_string_with_delay_P(const char *str, uint8_t interval) {
-    while (1) {
-        char ascii_code = pgm_read_byte(str);
-        if (!ascii_code) break;
-        if (ascii_code == SS_QMK_PREFIX) {
-            ascii_code = pgm_read_byte(++str);
-            if (ascii_code == SS_TAP_CODE) {
-                // tap
-                uint8_t keycode = pgm_read_byte(++str);
-                tap_code(keycode);
-            } else if (ascii_code == SS_DOWN_CODE) {
-                // down
-                uint8_t keycode = pgm_read_byte(++str);
-                register_code(keycode);
-            } else if (ascii_code == SS_UP_CODE) {
-                // up
-                uint8_t keycode = pgm_read_byte(++str);
-                unregister_code(keycode);
-            } else if (ascii_code == SS_DELAY_CODE) {
-                // delay
-                int     ms      = 0;
-                uint8_t keycode = pgm_read_byte(++str);
-                while (isdigit(keycode)) {
-                    ms *= 10;
-                    ms += keycode - '0';
-                    keycode = pgm_read_byte(++str);
-                }
-                while (ms--)
-                    wait_ms(1);
-            }
-        } else {
-            send_char(ascii_code);
-        }
-        ++str;
+        ++string;
         // interval
         {
             uint8_t ms = interval;
@@ -250,17 +203,17 @@ void send_char(char ascii_code) {
     bool    is_dead    = PGM_LOADBIT(ascii_to_dead_lut, (uint8_t)ascii_code);
 
     if (is_shifted) {
-        register_code(KC_LSFT);
+        register_code(KC_LEFT_SHIFT);
     }
     if (is_altgred) {
-        register_code(KC_RALT);
+        register_code(KC_RIGHT_ALT);
     }
     tap_code(keycode);
     if (is_altgred) {
-        unregister_code(KC_RALT);
+        unregister_code(KC_RIGHT_ALT);
     }
     if (is_shifted) {
-        unregister_code(KC_LSFT);
+        unregister_code(KC_LEFT_SHIFT);
     }
     if (is_dead) {
         tap_code(KC_SPACE);
@@ -320,3 +273,52 @@ void tap_random_base64(void) {
             break;
     }
 }
+
+#if defined(__AVR__)
+void send_string_P(const char *string) {
+    send_string_with_delay_P(string, 0);
+}
+
+void send_string_with_delay_P(const char *string, uint8_t interval) {
+    while (1) {
+        char ascii_code = pgm_read_byte(string);
+        if (!ascii_code) break;
+        if (ascii_code == SS_QMK_PREFIX) {
+            ascii_code = pgm_read_byte(++string);
+            if (ascii_code == SS_TAP_CODE) {
+                // tap
+                uint8_t keycode = pgm_read_byte(++string);
+                tap_code(keycode);
+            } else if (ascii_code == SS_DOWN_CODE) {
+                // down
+                uint8_t keycode = pgm_read_byte(++string);
+                register_code(keycode);
+            } else if (ascii_code == SS_UP_CODE) {
+                // up
+                uint8_t keycode = pgm_read_byte(++string);
+                unregister_code(keycode);
+            } else if (ascii_code == SS_DELAY_CODE) {
+                // delay
+                int     ms      = 0;
+                uint8_t keycode = pgm_read_byte(++string);
+                while (isdigit(keycode)) {
+                    ms *= 10;
+                    ms += keycode - '0';
+                    keycode = pgm_read_byte(++string);
+                }
+                while (ms--)
+                    wait_ms(1);
+            }
+        } else {
+            send_char(ascii_code);
+        }
+        ++string;
+        // interval
+        {
+            uint8_t ms = interval;
+            while (ms--)
+                wait_ms(1);
+        }
+    }
+}
+#endif
diff --git a/quantum/send_string/send_string.h b/quantum/send_string/send_string.h
new file mode 100644
index 0000000000..4eb55b88dc
--- /dev/null
+++ b/quantum/send_string/send_string.h
@@ -0,0 +1,152 @@
+/* Copyright 2021
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+/**
+ * \defgroup send_string
+ *
+ * Send String API. These functions allow you to create macros by typing out sequences of keystrokes.
+ * \{
+ */
+
+#include <stdint.h>
+
+#include "progmem.h"
+#include "send_string_keycodes.h"
+
+// Look-Up Tables (LUTs) to convert ASCII character to keycode sequence.
+extern const uint8_t ascii_to_shift_lut[16];
+extern const uint8_t ascii_to_altgr_lut[16];
+extern const uint8_t ascii_to_dead_lut[16];
+extern const uint8_t ascii_to_keycode_lut[128];
+
+// clang-format off
+#define KCLUT_ENTRY(a, b, c, d, e, f, g, h) \
+    ( ((a) ? 1 : 0) << 0 \
+    | ((b) ? 1 : 0) << 1 \
+    | ((c) ? 1 : 0) << 2 \
+    | ((d) ? 1 : 0) << 3 \
+    | ((e) ? 1 : 0) << 4 \
+    | ((f) ? 1 : 0) << 5 \
+    | ((g) ? 1 : 0) << 6 \
+    | ((h) ? 1 : 0) << 7 )
+// clang-format on
+
+/**
+ * \brief Type out a string of ASCII characters.
+ *
+ * This function simply calls `send_string_with_delay(string, 0)`.
+ *
+ * Most keycodes from the basic keycode range are also supported by way of a special sequence - see `send_string_keycodes.h`.
+ *
+ * \param string The string to type out.
+ */
+void send_string(const char *string);
+
+/**
+ * \brief Type out a string of ASCII characters, with a delay between each character.
+ *
+ * \param string The string to type out.
+ * \param interval The amount of time, in milliseconds, to wait before typing the next character.
+ */
+void send_string_with_delay(const char *string, uint8_t interval);
+
+/**
+ * \brief Type out an ASCII character.
+ *
+ * \param ascii_code The character to type.
+ */
+void send_char(char ascii_code);
+
+/**
+ * \brief Type out an eight digit (unsigned 32-bit) hexadecimal value.
+ *
+ * The format is `[0-9a-f]{8}`, eg. `00000000` through `ffffffff`.
+ *
+ * \param number The value to type, from 0 to 4,294,967,295.
+ */
+void send_dword(uint32_t number);
+
+/**
+ * \brief Type out a four digit (unsigned 16-bit) hexadecimal value.
+ *
+ * The format is `[0-9a-f]{4}`, eg. `0000` through `ffff`.
+ *
+ * \param number The value to type, from 0 to 65,535.
+ */
+void send_word(uint16_t number);
+
+/**
+ * \brief Type out a two digit (8-bit) hexadecimal value.
+ *
+ * The format is `[0-9a-f]{2}`, eg. `00` through `ff`.
+ *
+ * \param number The value to type, from 0 to 255.
+ */
+void send_byte(uint8_t number);
+
+/**
+ * \brief Type out a single hexadecimal digit.
+ *
+ * The format is `[0-9a-f]{1}`, eg. `0` through `f`.
+ *
+ * \param number The value to type, from 0 to 15.
+ */
+void send_nibble(uint8_t number);
+
+/**
+ * \brief Type a pseudorandom character from the set `A-Z`, `a-z`, `0-9`, `+` and `/`.
+ */
+void tap_random_base64(void);
+
+#if defined(__AVR__) || defined(__DOXYGEN__)
+/**
+ * \brief Type out a PROGMEM string of ASCII characters.
+ *
+ * On ARM devices, this function is simply an alias for send_string_with_delay(string, 0).
+ *
+ * \param string The string to type out.
+ */
+void send_string_P(const char *string);
+
+/**
+ * \brief Type out a PROGMEM string of ASCII characters, with a delay between each character.
+ *
+ * On ARM devices, this function is simply an alias for send_string_with_delay(string, interval).
+ *
+ * \param string The string to type out.
+ * \param interval The amount of time, in milliseconds, to wait before typing the next character.
+ */
+void send_string_with_delay_P(const char *string, uint8_t interval);
+#else
+#    define send_string_P(string) send_string_with_delay(string, 0)
+#    define send_string_with_delay_P(string, interval) send_string_with_delay(string, interval)
+#endif
+
+/**
+ * \brief Shortcut macro for send_string_with_delay_P(PSTR(string), 0).
+ *
+ * On ARM devices, this define evaluates to send_string_with_delay(string, 0).
+ */
+#define SEND_STRING(string) send_string_with_delay_P(PSTR(string), 0)
+
+/**
+ * \brief Shortcut macro for send_string_with_delay_P(PSTR(string), interval).
+ *
+ * On ARM devices, this define evaluates to send_string_with_delay(string, interval).
+ */
+#define SEND_STRING_DELAY(string, interval) send_string_with_delay_P(PSTR(string), interval)
+
+/** \} */
diff --git a/quantum/send_string/send_string_keycodes.h b/quantum/send_string/send_string_keycodes.h
new file mode 100644
index 0000000000..7017e03d5a
--- /dev/null
+++ b/quantum/send_string/send_string_keycodes.h
@@ -0,0 +1,434 @@
+/* Copyright 2019
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+
+// clang-format off
+
+/* Punctuation */
+#define X_ENT  X_ENTER
+#define X_ESC  X_ESCAPE
+#define X_BSPC X_BSPACE
+#define X_SPC  X_SPACE
+#define X_MINS X_MINUS
+#define X_EQL  X_EQUAL
+#define X_LBRC X_LBRACKET
+#define X_RBRC X_RBRACKET
+#define X_BSLS X_BSLASH
+#define X_NUHS X_NONUS_HASH
+#define X_SCLN X_SCOLON
+#define X_QUOT X_QUOTE
+#define X_GRV  X_GRAVE
+#define X_COMM X_COMMA
+#define X_SLSH X_SLASH
+#define X_NUBS X_NONUS_BSLASH
+
+/* Lock Keys */
+#define X_CLCK X_CAPSLOCK
+#define X_CAPS X_CAPSLOCK
+#define X_SLCK X_SCROLLLOCK
+#define X_NLCK X_NUMLOCK
+#define X_LCAP X_LOCKING_CAPS
+#define X_LNUM X_LOCKING_NUM
+#define X_LSCR X_LOCKING_SCROLL
+
+/* Commands */
+#define X_PSCR X_PSCREEN
+#define X_PAUS X_PAUSE
+#define X_BRK  X_PAUSE
+#define X_INS  X_INSERT
+#define X_DEL  X_DELETE
+#define X_PGDN X_PGDOWN
+#define X_RGHT X_RIGHT
+#define X_APP  X_APPLICATION
+#define X_EXEC X_EXECUTE
+#define X_SLCT X_SELECT
+#define X_AGIN X_AGAIN
+#define X_PSTE X_PASTE
+#define X_ERAS X_ALT_ERASE
+#define X_CLR  X_CLEAR
+
+/* Keypad */
+#define X_PSLS X_KP_SLASH
+#define X_PAST X_KP_ASTERISK
+#define X_PMNS X_KP_MINUS
+#define X_PPLS X_KP_PLUS
+#define X_PENT X_KP_ENTER
+#define X_P1   X_KP_1
+#define X_P2   X_KP_2
+#define X_P3   X_KP_3
+#define X_P4   X_KP_4
+#define X_P5   X_KP_5
+#define X_P6   X_KP_6
+#define X_P7   X_KP_7
+#define X_P8   X_KP_8
+#define X_P9   X_KP_9
+#define X_P0   X_KP_0
+#define X_PDOT X_KP_DOT
+#define X_PEQL X_KP_EQUAL
+#define X_PCMM X_KP_COMMA
+
+/* Japanese specific */
+#define X_ZKHK X_GRAVE
+#define X_RO   X_INT1
+#define X_KANA X_INT2
+#define X_JYEN X_INT3
+#define X_HENK X_INT4
+#define X_MHEN X_INT5
+
+/* Korean specific */
+#define X_HAEN X_LANG1
+#define X_HANJ X_LANG2
+
+/* Modifiers */
+#define X_LCTL X_LCTRL
+#define X_LSFT X_LSHIFT
+#define X_LOPT X_LALT
+#define X_LCMD X_LGUI
+#define X_LWIN X_LGUI
+#define X_RCTL X_RCTRL
+#define X_RSFT X_RSHIFT
+#define X_ALGR X_RALT
+#define X_ROPT X_RALT
+#define X_RCMD X_RGUI
+#define X_RWIN X_RGUI
+
+/* Generic Desktop Page (0x01) */
+#define X_PWR  X_SYSTEM_POWER
+#define X_SLEP X_SYSTEM_SLEEP
+#define X_WAKE X_SYSTEM_WAKE
+
+/* Consumer Page (0x0C) */
+#define X_MUTE X_AUDIO_MUTE
+#define X_VOLU X_AUDIO_VOL_UP
+#define X_VOLD X_AUDIO_VOL_DOWN
+#define X_MNXT X_MEDIA_NEXT_TRACK
+#define X_MPRV X_MEDIA_PREV_TRACK
+#define X_MSTP X_MEDIA_STOP
+#define X_MPLY X_MEDIA_PLAY_PAUSE
+#define X_MSEL X_MEDIA_SELECT
+#define X_EJCT X_MEDIA_EJECT
+#define X_CALC X_CALCULATOR
+#define X_MYCM X_MY_COMPUTER
+#define X_WSCH X_WWW_SEARCH
+#define X_WHOM X_WWW_HOME
+#define X_WBAK X_WWW_BACK
+#define X_WFWD X_WWW_FORWARD
+#define X_WSTP X_WWW_STOP
+#define X_WREF X_WWW_REFRESH
+#define X_WFAV X_WWW_FAVORITES
+#define X_MFFD X_MEDIA_FAST_FORWARD
+#define X_MRWD X_MEDIA_REWIND
+#define X_BRIU X_BRIGHTNESS_UP
+#define X_BRID X_BRIGHTNESS_DOWN
+
+/* System Specific */
+#define X_BRMU X_PAUSE
+#define X_BRMD X_SCROLLLOCK
+
+/* Mouse Keys */
+#define X_MS_U X_MS_UP
+#define X_MS_D X_MS_DOWN
+#define X_MS_L X_MS_LEFT
+#define X_MS_R X_MS_RIGHT
+#define X_BTN1 X_MS_BTN1
+#define X_BTN2 X_MS_BTN2
+#define X_BTN3 X_MS_BTN3
+#define X_BTN4 X_MS_BTN4
+#define X_BTN5 X_MS_BTN5
+#define X_WH_U X_MS_WH_UP
+#define X_WH_D X_MS_WH_DOWN
+#define X_WH_L X_MS_WH_LEFT
+#define X_WH_R X_MS_WH_RIGHT
+#define X_ACL0 X_MS_ACCEL0
+#define X_ACL1 X_MS_ACCEL1
+#define X_ACL2 X_MS_ACCEL2
+
+/* Keyboard/Keypad Page (0x07) */
+#define X_A                  04
+#define X_B                  05
+#define X_C                  06
+#define X_D                  07
+#define X_E                  08
+#define X_F                  09
+#define X_G                  0a
+#define X_H                  0b
+#define X_I                  0c
+#define X_J                  0d
+#define X_K                  0e
+#define X_L                  0f
+#define X_M                  10
+#define X_N                  11
+#define X_O                  12
+#define X_P                  13
+#define X_Q                  14
+#define X_R                  15
+#define X_S                  16
+#define X_T                  17
+#define X_U                  18
+#define X_V                  19
+#define X_W                  1a
+#define X_X                  1b
+#define X_Y                  1c
+#define X_Z                  1d
+#define X_1                  1e
+#define X_2                  1f
+#define X_3                  20
+#define X_4                  21
+#define X_5                  22
+#define X_6                  23
+#define X_7                  24
+#define X_8                  25
+#define X_9                  26
+#define X_0                  27
+#define X_ENTER              28
+#define X_ESCAPE             29
+#define X_BSPACE             2a
+#define X_TAB                2b
+#define X_SPACE              2c
+#define X_MINUS              2d
+#define X_EQUAL              2e
+#define X_LBRACKET           2f
+#define X_RBRACKET           30
+#define X_BSLASH             31
+#define X_NONUS_HASH         32
+#define X_SCOLON             33
+#define X_QUOTE              34
+#define X_GRAVE              35
+#define X_COMMA              36
+#define X_DOT                37
+#define X_SLASH              38
+#define X_CAPSLOCK           39
+#define X_F1                 3a
+#define X_F2                 3b
+#define X_F3                 3c
+#define X_F4                 3d
+#define X_F5                 3e
+#define X_F6                 3f
+#define X_F7                 40
+#define X_F8                 41
+#define X_F9                 42
+#define X_F10                43
+#define X_F11                44
+#define X_F12                45
+#define X_PSCREEN            46
+#define X_SCROLLLOCK         47
+#define X_PAUSE              48
+#define X_INSERT             49
+#define X_HOME               4a
+#define X_PGUP               4b
+#define X_DELETE             4c
+#define X_END                4d
+#define X_PGDOWN             4e
+#define X_RIGHT              4f
+#define X_LEFT               50
+#define X_DOWN               51
+#define X_UP                 52
+#define X_NUMLOCK            53
+#define X_KP_SLASH           54
+#define X_KP_ASTERISK        55
+#define X_KP_MINUS           56
+#define X_KP_PLUS            57
+#define X_KP_ENTER           58
+#define X_KP_1               59
+#define X_KP_2               5a
+#define X_KP_3               5b
+#define X_KP_4               5c
+#define X_KP_5               5d
+#define X_KP_6               5e
+#define X_KP_7               5f
+#define X_KP_8               60
+#define X_KP_9               61
+#define X_KP_0               62
+#define X_KP_DOT