Initial potentiometer support

Author: zvecr

builddefs/common_features.mk

@@ -905,6 +905,10 @@ ifeq ($(strip $(ENCODER_ENABLE)), yes)
     endif
 endif
 
+ifeq ($(strip $(POTENTIOMETER_ENABLE)), yes)
+    ANALOG_DRIVER_REQUIRED = yes
+endif
+
 VALID_WS2812_DRIVER_TYPES := bitbang custom i2c pwm spi vendor
 
 WS2812_DRIVER ?= bitbang

builddefs/generic_features.mk

@@ -40,6 +40,7 @@ GENERIC_FEATURES = \
     MOUSEKEY \
     MUSIC \
     OS_DETECTION \
+    POTENTIOMETER \
     PROGRAMMABLE_BUTTON \
     REPEAT_KEY \
     SECURE \

data/mappings/info_config.hjson

@@ -117,6 +117,9 @@
     "ONESHOT_TIMEOUT": {"info_key": "oneshot.timeout", "value_type": "int"},
     "ONESHOT_TAP_TOGGLE": {"info_key": "oneshot.tap_toggle", "value_type": "int"},
 
+    // Potentiometer
+    "POTENTIOMETER_PINS": {"info_key": "potentiometer.pins", "value_type": "array"},
+
     // PS/2
     "PS2_CLOCK_PIN": {"info_key": "ps2.clock_pin"},
     "PS2_DATA_PIN": {"info_key": "ps2.data_pin"},

data/mappings/info_rules.hjson

@@ -32,6 +32,7 @@
     "NO_USB_STARTUP_CHECK": {"info_key": "usb.no_startup_check", "value_type": "bool"},
     "PIN_COMPATIBLE": {"info_key": "pin_compatible"},
     "PLATFORM_KEY": {"info_key": "platform_key", "to_json": false},
+    "POTENTIOMETER_ENABLE": {"info_key": "potentiometer.enabled", "value_type": "bool"},
     "PS2_DRIVER": {"info_key": "ps2.driver"},
     "PS2_ENABLE": {"info_key": "ps2.enabled", "value_type": "bool"},
     "PS2_MOUSE_ENABLE": {"info_key": "ps2.mouse_enabled", "value_type": "bool"},

data/schemas/keyboard.jsonschema

@@ -417,6 +417,13 @@
                 "timeout": {"$ref": "qmk.definitions.v1#/unsigned_int"}
             }
         },
+        "potentiometer": {
+            "type": "object",
+            "properties": {
+                "enabled": {"type": "boolean"},
+                "pins": {"$ref": "qmk.definitions.v1#/mcu_pin_array"}
+            }
+        },
         "led_matrix": {
             "type": "object",
             "properties": {

docs/_summary.md

@@ -123,6 +123,7 @@
     * [LED Indicators](feature_led_indicators.md)
     * [MIDI](feature_midi.md)
     * [Pointing Device](feature_pointing_device.md)
+    * [Potentiometer](feature_potentiometers.md)
     * [PS/2 Mouse](feature_ps2_mouse.md)
     * [Split Keyboard](feature_split_keyboard.md)
     * [Stenography](feature_stenography.md)

docs/feature_potentiometers.md

@@ -0,0 +1,35 @@
+# Potentiometers
+
+Add this to your `rules.mk`:
+
+```make
+POTENTIOMETER_ENABLE = yes
+```
+
+and this to your `config.h`:
+
+```c
+#define POTENTIOMETER_PINS { B0 }
+```
+
+## Callbacks
+
+The callback functions can be inserted into your `<keyboard>.c`:
+
+```c
+bool potentiometer_update_kb(uint8_t index, uint16_t value) {
+    if (!potentiometer_update_user(index, value)) {
+        midi_send_cc(&midi_device, 2, 0x3E, 0x7F + (value >> 3));
+    }
+    return true;
+}
+```
+
+or `keymap.c`:
+
+```c
+bool potentiometer_update_user(uint8_t index, uint16_t value) {
+    midi_send_cc(&midi_device, 2, 0x3E, 0x7F + (value >> 3));
+    return false;
+}
+```

docs/reference_info_json.md

@@ -478,6 +478,17 @@ Configures [One Shot keys](one_shot_keys.md).
     * `timeout`
         * The amount of time before the key is released in milliseconds.
 
+## Potentiometer :id=potentiometer
+
+Configures the [Potentiometer](feature_Potentiometers.md) feature.
+
+* `potentiometer`
+    * `enabled`
+        * Enable the Potentiometer feature.
+        * Default: `false`
+    * `pins` (Required)
+        * The GPIO pin(s) connected to the Potentiometer(s).
+
 ## PS/2 :id=ps2
 
 Configures the [PS/2](feature_ps2_mouse.md) feature.

keyboards/gmmk/numpad/config.h

@@ -17,7 +17,7 @@
 
 #pragma once
 
-#define SLIDER_PIN B0
+#define POTENTIOMETER_PINS { B0 }
 #define MIDI_ADVANCED
 
 #define LOCKING_SUPPORT_ENABLE

keyboards/gmmk/numpad/keymaps/default/keymap.c

@@ -16,8 +16,6 @@ along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
 #include QMK_KEYBOARD_H
-#include "analog.h"
-#include "qmk_midi.h"
 
 // clang-format off
 const uint16_t PROGMEM keymaps[][MATRIX_ROWS][MATRIX_COLS] = {
@@ -43,18 +41,3 @@ const uint16_t PROGMEM keymaps[][MATRIX_ROWS][MATRIX_COLS] = {
     RGB_TOG,                         QK_BOOT
   )
 };
-
-// Potentiometer Slider, MIDI Control
-
-uint8_t divisor = 0;
-
-void slider(void) {
-    if (divisor++) { /* only run the slider function 1/256 times it's called */
-        return;
-    }
-    midi_send_cc(&midi_device, 2, 0x3E, 0x7F + (analogReadPin(SLIDER_PIN) >> 3));
-}
-
-void housekeeping_task_user(void) {
-    slider();
-}