1 files changed, 182 insertions, 6 deletions

diff --git a/readme.md b/readme.md
index 4eed2c776..be1510832 100644
--- a/readme.md
+++ b/readme.md
@@ -241,6 +241,7 @@ You can also add extra options at the end of the make command line, after the ta
 * `make COLOR=false` - turns off color output
 * `make SILENT=true` - turns off output besides errors/warnings
 * `make VERBOSE=true` - outputs all of the gcc stuff (not interesting, unless you need to debug)
+* `make EXTRAFLAGS=-E` - Preprocess the code without doing any compiling (useful if you are trying to debug #define commands)
 
 The make command itself also has some additional options, type `make --help` for more information. The most useful is probably `-jx`, which specifies that you want to compile using more than one CPU, the `x` represents the number of CPUs that you want to use. Setting that can greatly reduce the compile times, especially if you are compiling many keyboards/keymaps. I usually set it to one less than the number of CPUs that I have, so that I have some left for doing other things while it's compiling. Note that not all operating systems and make versions supports that option.
 
@@ -347,6 +348,10 @@ This allows you output audio on the C6 pin (needs abstracting). See the [audio s
 
 Use this to debug changes to variable values, see the [tracing variables](#tracing-variables) section for more information.
 
+`API_SYSEX_ENABLE`
+
+This enables using the Quantum SYSEX API to send strings (somewhere?)
+
 ### Customizing Makefile options on a per-keymap basis
 
 If your keymap directory has a file called `Makefile` (note the filename), any Makefile options you set in that file will take precedence over other Makefile options for your particular keyboard.
@@ -910,7 +915,33 @@ In `quantum/keymap_extras/`, you'll see various language files - these work the
 
 ## Unicode support
 
-You can currently send 4 hex digits with your OS-specific modifier key (RALT for OSX with the "Unicode Hex Input" layout, see [this article](http://www.poynton.com/notes/misc/mac-unicode-hex-input.html) to learn more) - this is currently limited to supporting one OS at a time, and requires a recompile for switching. 8 digit hex codes are being worked on. The keycode function is `UC(n)`, where *n* is a 4 digit hexidecimal. Enable from the Makefile.
+There are three Unicode keymap definition method available in QMK:
+
+### UNICODE_ENABLE
+
+Supports Unicode input up to 0xFFFF. The keycode function is `UC(n)` in
+keymap file, where *n* is a 4 digit hexadecimal.
+
+### UNICODEMAP_ENABLE
+
+Supports Unicode up to 0xFFFFFFFF. You need to maintain a separate mapping
+table `const uint32_t PROGMEM unicode_map[] = {...}` in your keymap file.
+The keycode function is `X(n)` where *n* is the array index of the mapping
+table.
+
+### UCIS_ENABLE
+
+TBD
+
+Unicode input in QMK works by inputing a sequence of characters to the OS,
+sort of like macro. Unfortunately, each OS has different ideas on how Unicode is inputted.
+
+This is the current list of Unicode input method in QMK:
+
+* UC_OSX: MacOS Unicode Hex Input support. Works only up to 0xFFFF. Disabled by default. To enable: go to System Preferences -> Keyboard -> Input Sources, and enable Unicode Hex.
+* UC_LNX: Unicode input method under Linux. Works up to 0xFFFFF. Should work almost anywhere on ibus enabled distros. Without ibus, this works under GTK apps, but rarely anywhere else.
+* UC_WIN: (not recommended) Windows built-in Unicode input. To enable: create registry key under `HKEY_CURRENT_USER\Control Panel\Input Method\EnableHexNumpad` of type `REG_SZ` called `EnableHexNumpad`, set its value to 1, and reboot. This method is not recommended because of reliability and compatibility issue, use WinCompose method below instead.
+* UC_WINC: Windows Unicode input using WinCompose. Requires [WinCompose](https://github.com/samhocevar/wincompose). Works reliably under many (all?) variations of Windows.
 
 ## Backlight Breathing
 
@@ -1135,12 +1166,12 @@ For this mod, you need an unused pin wiring to DI of WS2812 strip. After wiring
 
     RGBLIGHT_ENABLE = yes
 
-In order to use the underglow timer functions, you need to have `#define RGBLIGHT_TIMER` in your `config.h`, and have audio disabled (`AUDIO_ENABLE = no` in your Makefile).
+In order to use the underglow animation functions, you need to have `#define RGBLIGHT_ANIMATIONS` in your `config.h`.
 
 Please add the following options into your config.h, and set them up according your hardware configuration. These settings are for the `F4` pin by default:
 
     #define RGB_DI_PIN F4     // The pin your RGB strip is wired to
-    #define RGBLIGHT_TIMER    // Require for fancier stuff (not compatible with audio)
+    #define RGBLIGHT_ANIMATIONS    // Require for fancier stuff (not compatible with audio)
     #define RGBLED_NUM 14     // Number of LEDs
     #define RGBLIGHT_HUE_STEP 10
     #define RGBLIGHT_SAT_STEP 17
@@ -1156,20 +1187,165 @@ The firmware supports 5 different light effects, and the color (hue, saturation,
 
 Please note the USB port can only supply a limited amount of power to the keyboard (500mA by standard, however, modern computer and most usb hubs can provide 700+mA.). According to the data of NeoPixel from Adafruit, 30 WS2812 LEDs require a 5V 1A power supply, LEDs used in this mod should not more than 20.
 
+## PS/2 Mouse Support
+
+Its possible to hook up a PS/2 mouse (for example touchpads or trackpoints) to your keyboard as a composite device.
+
+Then, decide whether to use USART (best), interrupts (better) or busywait (not recommended), and enable the relevant option.
+
+### Busywait version
+
+Note: This is not recommended, you may encounter jerky movement or unsent inputs. Please use interrupt or USART version if possible.
+
+In rules.mk:
+
+```
+PS2_MOUSE_ENABLE = yes
+PS2_USE_BUSYWAIT = yes
+```
+
+In your keyboard config.h:
+
+```
+#ifdef PS2_USE_BUSYWAIT
+#   define PS2_CLOCK_PORT  PORTD
+#   define PS2_CLOCK_PIN   PIND
+#   define PS2_CLOCK_DDR   DDRD
+#   define PS2_CLOCK_BIT   1
+#   define PS2_DATA_PORT   PORTD
+#   define PS2_DATA_PIN    PIND
+#   define PS2_DATA_DDR    DDRD
+#   define PS2_DATA_BIT    2
+#endif
+```
+
+### Interrupt version
+
+The following example uses D2 for clock and D5 for data. You can use any INT or PCINT pin for clock, and any pin for data.
+
+In rules.mk:
+
+```
+PS2_MOUSE_ENABLE = yes
+PS2_USE_INT = yes
+```
+
+In your keyboard config.h:
+
+```
+#ifdef PS2_USE_INT
+#define PS2_CLOCK_PORT  PORTD
+#define PS2_CLOCK_PIN   PIND
+#define PS2_CLOCK_DDR   DDRD
+#define PS2_CLOCK_BIT   2
+#define PS2_DATA_PORT   PORTD
+#define PS2_DATA_PIN    PIND
+#define PS2_DATA_DDR    DDRD
+#define PS2_DATA_BIT    5
+
+#define PS2_INT_INIT()  do {    \
+    EICRA |= ((1<<ISC21) |      \
+              (0<<ISC20));      \
+} while (0)
+#define PS2_INT_ON()  do {      \
+    EIMSK |= (1<<INT2);         \
+} while (0)
+#define PS2_INT_OFF() do {      \
+    EIMSK &= ~(1<<INT2);        \
+} while (0)
+#define PS2_INT_VECT   INT2_vect
+#endif
+```
+
+### USART version
+
+To use USART on the ATMega32u4, you have to use PD5 for clock and PD2 for data. If one of those are unavailable, you need to use interrupt version.
+
+In rules.mk:
+
+```
+PS2_MOUSE_ENABLE = yes
+PS2_USE_USART = yes
+```
+
+In your keyboard config.h:
+
+```
+#ifdef PS2_USE_USART
+#define PS2_CLOCK_PORT  PORTD
+#define PS2_CLOCK_PIN   PIND
+#define PS2_CLOCK_DDR   DDRD
+#define PS2_CLOCK_BIT   5
+#define PS2_DATA_PORT   PORTD
+#define PS2_DATA_PIN    PIND
+#define PS2_DATA_DDR    DDRD
+#define PS2_DATA_BIT    2
+
+/* synchronous, odd parity, 1-bit stop, 8-bit data, sample at falling edge */
+/* set DDR of CLOCK as input to be slave */
+#define PS2_USART_INIT() do {   \
+    PS2_CLOCK_DDR &= ~(1<<PS2_CLOCK_BIT);   \
+    PS2_DATA_DDR &= ~(1<<PS2_DATA_BIT);     \
+    UCSR1C = ((1 << UMSEL10) |  \
+              (3 << UPM10)   |  \
+              (0 << USBS1)   |  \
+              (3 << UCSZ10)  |  \
+              (0 << UCPOL1));   \
+    UCSR1A = 0;                 \
+    UBRR1H = 0;                 \
+    UBRR1L = 0;                 \
+} while (0)
+#define PS2_USART_RX_INT_ON() do {  \
+    UCSR1B = ((1 << RXCIE1) |       \
+              (1 << RXEN1));        \
+} while (0)
+#define PS2_USART_RX_POLL_ON() do { \
+    UCSR1B = (1 << RXEN1);          \
+} while (0)
+#define PS2_USART_OFF() do {    \
+    UCSR1C = 0;                 \
+    UCSR1B &= ~((1 << RXEN1) |  \
+                (1 << TXEN1));  \
+} while (0)
+#define PS2_USART_RX_READY      (UCSR1A & (1<<RXC1))
+#define PS2_USART_RX_DATA       UDR1
+#define PS2_USART_ERROR         (UCSR1A & ((1<<FE1) | (1<<DOR1) | (1<<UPE1)))
+#define PS2_USART_RX_VECT       USART1_RX_vect
+#endif
+#endif
+#endif
+```
+
 ## Safety Considerations
 
 You probably don't want to "brick" your keyboard, making it impossible
 to rewrite firmware onto it.  Here are some of the parameters to show
 what things are (and likely aren't) too risky.
 
-- If a keyboard map does not include RESET, then, to get into DFU
+- If your keyboard map does not include RESET, then, to get into DFU
   mode, you will need to press the reset button on the PCB, which
-  requires unscrewing some bits.
+  requires unscrewing the bottom.
 - Messing with tmk_core / common files might make the keyboard
   inoperable
 - Too large a .hex file is trouble; `make dfu` will erase the block,
   test the size (oops, wrong order!), which errors out, failing to
-  flash the keyboard
+  flash the keyboard, leaving it in DFU mode.
+  - To this end, note that the maximum .hex file size on Planck is
+    7000h (28672 decimal)
+```Linking: .build/planck_rev4_cbbrowne.elf                                                            [OK]
+Creating load file for Flash: .build/planck_rev4_cbbrowne.hex                                       [OK]
+
+Size after:
+   text    data     bss     dec     hex filename
+      0   22396       0   22396    577c planck_rev4_cbbrowne.hex
+```
+  - The above file is of size 22396/577ch, which is less than
+    28672/7000h
+  - As long as you have a suitable alternative .hex file around, you
+    can retry, loading that one
+  - Some of the options you might specify in your keyboard's Makefile
+    consume extra memory; watch out for BOOTMAGIC_ENABLE,
+    MOUSEKEY_ENABLE, EXTRAKEY_ENABLE, CONSOLE_ENABLE, API_SYSEX_ENABLE
 - DFU tools do /not/ allow you to write into the bootloader (unless
   you throw in extra fruitsalad of options), so there is little risk
   there.