Added Auto Shift, tap key = normal, hold key = shifted state.

2 files changed, 162 insertions, 0 deletions

diff --git a/docs/feature_auto_shift.md b/docs/feature_auto_shift.md
new file mode 100644
index 0000000000..a054c36528
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+++ b/docs/feature_auto_shift.md
@@ -0,0 +1,161 @@
+# Auto Shift: Why do we need a shift key?
+
+Tap a key and you get its character. Tap a key, but hold it *slightly* longer
+and you get its shifted state. Viola! No shift key needeed!
+
+## Why Auto Shift?
+
+Many people suffer from various forms of RSI. A common cause is stretching your
+fingers repeitively long distances. For us on the keyboard, the pinky does that
+all too often when reaching for the shift key. Auto Shift looks to aliviate that
+problem.
+
+## How does it work?
+
+When you tap a key, it stays depressed for a short period of time before it is
+then released. This depressed time is a different length everyone. Auto Shift
+defines a constant `AUTO_SHIFT_TIMEOUT` which is typically set to twice your
+normal pressed state time. When you press a key, a timer starts and then stops
+when you release the key. If the time depressed is greater than or equal to the
+`AUTO_SHIFT_TIMEOUT` then a shifted version of the key is emitted. If the time
+is less than the `AUTO_SHIFT_TIMEOUT` time, then the normal state is emitted.
+
+## Are there limitations to Auto Shift?
+
+Yes, unfortunately.
+
+1. Key repeat will cease to work. For example, before if you wanted 20 'a'
+   characters, you could press and hold the 'a' key for a second or two. This no
+   longer works with Auto Shift because it is timing your depressed time instead
+   of emitting a depressed key state to your operating system.
+2. Auto Shift is disabled for any key press that is accompanied by one or more
+   modifiers. Thus, Ctrl+A that you hold for a really long time is not the same
+   as Ctrl+Shift+A.
+3. You will have characters that are shifted you did not intend on shifting, and
+   other characters you wanted shifted, but were not. This simply comes down to
+   practice. As we get in a hurry, we think we might have hit the key long enough
+   for a shifted version, but we did not. On the other hand, we may think we are
+   tapping the keys, but really we have held it for a little longer than
+   anticipated.
+
+## How do I enable Auto Shift?
+
+Add to your `rules.mk` in the keymap folder:
+
+    AUTO_SHIFT_ENABLE = YES
+
+If no `rules.mk` exists, you can create one.
+
+Then compile and install your new firmware with Auto Key enabled! That's it!
+
+## Configuring Auto Shift
+
+If desired, there is some configuration that can be done to change the
+behavior of Auto Shift. This is done by setting various variables the
+`config.h` file located in your keymap folder.
+
+If no `config.h` file exists, you can create one. A sample is
+
+    #ifndef CONFIG_USER_H
+    #define CONFIG_USER_H
+
+    #include "../../config.h"
+
+    #define AUTO_SHIFT_TIMEOUT 150
+    #define NO_AUTO_SHIFT_SPECIAL
+
+    #endif
+
+### AUTO_SHIFT_TIMEOUT (value in ms)
+
+This controls how long you have to hold a key before you get the shifted state.
+Obviously, this is different for everyone. For the common person a setting of
+135 to 150 works great but one should start with a value of at least 175, which
+is the  default value. Then work down from there. The idea is to have as short
+of a time required to get the shifted state without having false positives.
+
+Play with this value until things are perfect. Many find that all will work well
+at a given value, but one or two keys will still emit the shifted state on
+occassion. This is simply due to habit and holding some keys a little longer
+than others. Once you find this value, work on tapping your problem keys a little
+quicker than normal and you will be set.
+
+{% hint style='info' %}
+Auto Shift has three special keys that can help you get this value right very
+quick. See "Auto Shift Setup" for more details!
+{% endhint %}
+
+### NO_AUTO_SHIFT_SPECIAL (simple define)
+
+Do not Auto Shift special keys, which include -_, =+, [{, ]}, ;:, '", ,<, .>,
+and /?
+
+### NO_AUTO_SHIFT_NUMERIC (simple define)
+
+Do not Auto Shift numeric keys, zero through nine.
+
+### NO_AUTO_SHIFT_ALPHA (simple define)
+
+Do not Auto Shift alpha characters, which include A through Z.
+
+## Using Auto Shift Setup
+
+This will enable you to define three keys temporailiy to increase, decrease and report your `AUTO_SHIFT_TIMEOUT`.
+
+### Setup
+
+Map three keys temporarily in your keymap:
+
+| Key Name | Description                                         |
+|----------|-----------------------------------------------------|
+| KC_ASDN  | Lower the Auto Shift timeout variable (down)        |
+| KC_ASUP  | Raise the Auto Shift timeout variable (up)          |
+| KC_ASRP  | Report your current Auto Shift timeout value        |
+
+Compile and upload your new firmware.
+
+### Use
+
+It is important to note that during these tests, you should be typing
+completely normal and with no intention of shifted keys.
+
+1. Type multiple sentences of alphabetical letters.
+2. Observe any upper case letters.
+3. If there are none, press the key you have mapped to `KC_ASDN` to decrease
+   time Auto Shift timeout value and go back to step 1.
+4. If there are some upper case letters, decide if you need to work on tapping
+   those keys with less down time, or if you need to increase the timeout.
+5. If you decide to increase the timeout, press the key you have mapped to
+   `KC_ASUP` and go back to step 1.
+6. Once you are happy with your results, press the key you have mapped to
+   `KC_ASRP`. The keyboard will type by itself the value of your
+   `AUTO_SHIFT_TIMEOUT`.
+7. Update `AUTO_SHIFT_TIMEOUT` in your `config.h` with the value reported.
+8. Remove `AUTO_SHIFT_SETUP` from your `config.h`.
+9. Remove the key bindings `KC_ASDN`, `KC_ASUP` and `KC_ASRP`.
+10. Compile and upload your new firmware.
+
+#### An example run
+
+\'\'\'
+hello world. my name is john doe. i am a computer programmer playing with
+keyboards right now.
+
+[PRESS KC_ASDN quite a few times]
+
+heLLo woRLd. mY nAMe is JOHn dOE. i AM A compUTeR proGRaMMER PlAYiNG witH
+KEYboArDS RiGHT NOw.
+
+[PRESS KC_ASUP a few times]
+
+hello world. my name is john Doe. i am a computer programmer play with
+keyboarDs right now.
+
+[PRESS KC_ASRP]
+
+115
+\'\'\'
+
+The keyboard typed `115` which represents your current `AUTO_SHIFT_TIMEOUT`
+value. You are now set! Practice on the *D* key a little bit that showed up
+in the testing and you'll be golden.
diff --git a/docs/understanding_qmk.md b/docs/understanding_qmk.md
index 2ac4f30365..99c2306d66 100644
--- a/docs/understanding_qmk.md
+++ b/docs/understanding_qmk.md
@@ -147,6 +147,7 @@ The `process_record()` function itself is deceptively simple, but hidden within
     * [`bool process_unicode(uint16_t keycode, keyrecord_t *record)`](https://github.com/qmk/qmk_firmware/blob/master/quantum/process_keycode/process_unicode.c#L22)
     * [`bool process_ucis(uint16_t keycode, keyrecord_t *record)`](https://github.com/qmk/qmk_firmware/blob/master/quantum/process_keycode/process_ucis.c#L91)
     * [`bool process_printer(uint16_t keycode, keyrecord_t *record)`](https://github.com/qmk/qmk_firmware/blob/master/quantum/process_keycode/process_printer.c#L77)
+    * [`bool process_auto_shift(uint16_t keycode, keyrecord_t *record)`](https://github.com/qmk/qmk_firmware/blob/master/quantum/process_keycode/process_auto_shift.c#L47)
     * [`bool process_unicode_map(uint16_t keycode, keyrecord_t *record)`](https://github.com/qmk/qmk_firmware/blob/master/quantum/process_keycode/process_unicodemap.c#L47)
     * [Identify and process quantum specific keycodes](https://github.com/qmk/qmk_firmware/blob/master/quantum/quantum.c#L211)