Make quantum/split_common/serial.[ch] configurable (#4419)

[qmk_firmware.git] / docs / config_options.md

diff --git a/docs/config_options.md b/docs/config_options.md
index c4921c21d7621501f0f36bfd827bc695175250e5..bea4acb010aad836e4b364002bf1c0bc87c1a45d 100644 (file)
--- a/docs/config_options.md
+++ b/docs/config_options.md
@@ -160,6 +160,8 @@ If you define these options you will enable the associated feature, which may in
   * Set this to the number of combos that you're using in the [Combo](feature_combo.md) feature.
 * `#define COMBO_TERM 200`
   * how long for the Combo keys to be detected. Defaults to `TAPPING_TERM` if not defined.
+* `#define TAP_CODE_DELAY 100`
+  * Sets the delay between `register_code` and `unregister_code`, if you're having issues with it registering properly (common on VUSB boards). The value is in milliseconds.
 
 ## RGB Light Configuration
 
@@ -196,6 +198,9 @@ Split Keyboard specific options, make sure you have 'SPLIT_KEYBOARD = yes' in yo
 * `#define USE_I2C`
   * For using I2C instead of Serial (defaults to serial)
 
+* `#define SOFT_SERIAL_PIN D0`
+  * When using serial, define this. `D0` or `D1`,`D2`,`D3`,`E6`.
+
 # The `rules.mk` File
 
 This is a [make](https://www.gnu.org/software/make/manual/make.html) file that is included by the top-level `Makefile`. It is used to set some information about the MCU that we will be compiling for as well as enabling and disabling certain features.
@@ -261,3 +266,32 @@ Use these to enable or disable building certain features. The more you have enab
   * Forces the keyboard to wait for a USB connection to be established before it starts up
 * `NO_USB_STARTUP_CHECK`
   * Disables usb suspend check after keyboard startup. Usually the keyboard waits for the host to wake it up before any tasks are performed. This is useful for split keyboards as one half will not get a wakeup call but must send commands to the master.
+
+## USB Endpoint Limitations
+
+In order to provide services over USB, QMK has to use USB endpoints.
+These are a finite resource: each microcontroller has only a certain number.
+This limits what features can be enabled together.
+If the available endpoints are exceeded, a build error is thrown.
+
+The following features can require separate endpoints:
+
+* `MOUSEKEY_ENABLE`
+* `EXTRAKEY_ENABLE`
+* `CONSOLE_ENABLE`
+* `NKRO_ENABLE`
+* `MIDI_ENABLE`
+* `RAW_ENABLE`
+* `VIRTSER_ENABLE`
+
+In order to improve utilisation of the endpoints, the HID features can be combined to use a single endpoint.
+By default, `MOUSEKEY`, `EXTRAKEY`, and `NKRO` are combined into a single endpoint.
+
+The base keyboard functionality can also be combined into the endpoint,
+by setting `KEYBOARD_SHARED_EP = yes`.
+This frees up one more endpoint,
+but it can prevent the keyboard working in some BIOSes,
+as they do not implement Boot Keyboard protocol switching.
+
+Combining the mouse also breaks Boot Mouse compatibility.
+The mouse can be uncombined by setting `MOUSE_SHARED_EP = no` if this functionality is required.