Further refactoring of joystick feature (qmk#18437)

docs/feature_joystick.md

@@ -70,71 +70,44 @@ When the ADC reads 900 or higher, the returned axis value will be -127, whereas
 
 In this example, the first axis will be read from the `A4` pin while `B0` is set high and `A7` is set low, using `analogReadPin()`, whereas the second axis will not be read.
 
-In order to give a value to the second axis, you can do so in any customizable entry point: as an action, in `process_record_user()` or in `matrix_scan_user()`, or even in `joystick_task()` which is called even when no key has been pressed.
-You assign a value by writing to `joystick_status.axes[axis_index]` a signed 8-bit value (ranging from -127 to 127). Then it is necessary to assign the flag `JS_UPDATED` to `joystick_status.status` in order for an updated HID report to be sent.
+#### Virtual Axes
 
-The following example writes two axes based on keypad presses, with `KC_P5` as a precision modifier:
+To give a value to virtual axes, call `joystick_set_axis(axis, value)`.
+
+The following example adjusts two virtual axes (X and Y) based on keypad presses, with `KC_P5` as a precision modifier:
 
 ```c
-#ifdef ANALOG_JOYSTICK_ENABLE
-static uint8_t precision_val = 70;
-static uint8_t axesFlags = 0;
-enum axes {
-    Precision = 1,
-    Axis1High = 2,
-    Axis1Low = 4,
-    Axis2High = 8,
-    Axis2Low = 16
+joystick_config_t joystick_axes[JOYSTICK_AXES_COUNT] = {
+    [0] = JOYSTICK_AXIS_VIRTUAL, // x
+    [1] = JOYSTICK_AXIS_VIRTUAL  // y
 };
-#endif
+
+static bool precision = false;
+static uint16_t precision_mod = 64;
+static uint16_t axis_val = 127;
 
 bool process_record_user(uint16_t keycode, keyrecord_t *record) {
-    switch(keycode) {
-#ifdef ANALOG_JOYSTICK_ENABLE
-        // virtual joystick
-#    if JOYSTICK_AXES_COUNT > 1
+    int16_t precision_val = axis_val;
+    if (precision) {
+        precision_val -= precision_mod;
+    }
+
+    switch (keycode) {
         case KC_P8:
-            if (record->event.pressed) {
-                axesFlags |= Axis2Low;
-            } else {
-                axesFlags &= ~Axis2Low;
-            }
-            joystick_status.status |= JS_UPDATED;
-            break;
+            joystick_set_axis(1, record->event.pressed ? -precision_val : 0);
+            return false;
         case KC_P2:
-            if (record->event.pressed) {
-                axesFlags |= Axis2High;
-            } else {
-                axesFlags &= ~Axis2High;
-            }
-            joystick_status.status |= JS_UPDATED;
-            break;
-#    endif
+            joystick_set_axis(1, record->event.pressed ? precision_val : 0);
+            return false;
         case KC_P4:
-            if (record->event.pressed) {
-                axesFlags |= Axis1Low;
-            } else {
-                axesFlags &= ~Axis1Low;
-            }
-            joystick_status.status |= JS_UPDATED;
-            break;
+            joystick_set_axis(0, record->event.pressed ? -precision_val : 0);
+            return false;
         case KC_P6:
-            if (record->event.pressed) {
-                axesFlags |= Axis1High;
-            } else {
-                axesFlags &= ~Axis1High;
-            }
-            joystick_status.status |= JS_UPDATED;
-            break;
+            joystick_set_axis(0, record->event.pressed ? precision_val : 0);
+            return false;
         case KC_P5:
-            if (record->event.pressed) {
-                axesFlags |= Precision;
-            } else {
-                axesFlags &= ~Precision;
-            }
-            joystick_status.status |= JS_UPDATED;
-            break;
-#endif
+            precision = record->event.pressed;
+            return false;
     }
     return true;
 }

keyboards/handwired/onekey/keymaps/joystick/keymap.c

@@ -10,11 +10,7 @@ const uint16_t PROGMEM keymaps[][MATRIX_ROWS][MATRIX_COLS] = {
 
 void matrix_scan_user() {
     int16_t val = (((uint32_t)timer_read() % 5000 - 2500) * 255) / 5000;
-
-    if (val != joystick_status.axes[1]) {
-        joystick_status.axes[1] = val;
-        joystick_status.status |= JS_UPDATED;
-    }
+    joystick_set_axis(1, val);
 }
 
 // Joystick config

keyboards/synthlabs/solo/keymaps/gamepad/keymap.c

@@ -3,8 +3,6 @@
 
 #include QMK_KEYBOARD_H
 
-#include "joystick.h"
-
 const uint16_t PROGMEM keymaps[][MATRIX_ROWS][MATRIX_COLS] = {
     [0] = LAYOUT_all(
                                     JS_BUTTON0,JS_BUTTON1,JS_BUTTON2,JS_BUTTON3,JS_BUTTON4,JS_BUTTON5,JS_BUTTON6,
@@ -24,11 +22,8 @@ joystick_config_t joystick_axes[JOYSTICK_AXES_COUNT] = {
 
 bool encoder_update_kb(uint8_t index, bool clockwise) {
     joystick_position += (clockwise ? 2 : -2) * (full_joystick_value / pulses_per_revolution);  // +2 and -2 are used, since +1.0 and -1.0 axis output refers to positions at half of a full rotation
+    joystick_set_axis(0, joystick_position);
 
-    if (joystick_position != joystick_status.axes[0]) {
-        joystick_status.axes[0] = joystick_position;
-        joystick_status.status |= JS_UPDATED;
-    }
     return true;
 }
 

quantum/joystick.c

@@ -1,5 +1,24 @@
+/* Copyright 2022
+ *
+ * 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 "joystick.h"
 
+#include "analog.h"
+#include "wait.h"
+
 // clang-format off
 joystick_t joystick_status = {
     .buttons = {0},
@@ -15,12 +34,13 @@ joystick_t joystick_status = {
 // array defining the reading of analog values for each axis
 __attribute__((weak)) joystick_config_t joystick_axes[JOYSTICK_AXES_COUNT] = {};
 
-// to be implemented in the hid protocol library
-void send_joystick_packet(joystick_t *joystick);
+__attribute__((weak)) void joystick_task(void) {
+    joystick_read_axes();
+}
 
 void joystick_flush(void) {
     if ((joystick_status.status & JS_UPDATED) > 0) {
-        send_joystick_packet(&joystick_status);
+        host_joystick_send(&joystick_status);
         joystick_status.status &= ~JS_UPDATED;
     }
 }
@@ -36,3 +56,75 @@ void unregister_joystick_button(uint8_t button) {
     joystick_status.status |= JS_UPDATED;
     joystick_flush();
 }
+
+int16_t joystick_read_axis(uint8_t axis) {
+    // disable pull-up resistor
+    writePinLow(joystick_axes[axis].input_pin);
+
+    // if pin was a pull-up input, we need to uncharge it by turning it low
+    // before making it a low input
+    setPinOutput(joystick_axes[axis].input_pin);
+
+    wait_us(10);
+
+    if (joystick_axes[axis].output_pin != JS_VIRTUAL_AXIS) {
+        setPinOutput(joystick_axes[axis].output_pin);
+        writePinHigh(joystick_axes[axis].output_pin);
+    }
+
+    if (joystick_axes[axis].ground_pin != JS_VIRTUAL_AXIS) {
+        setPinOutput(joystick_axes[axis].ground_pin);
+        writePinLow(joystick_axes[axis].ground_pin);
+    }
+
+    wait_us(10);
+
+    setPinInput(joystick_axes[axis].input_pin);
+
+    wait_us(10);
+
+#if defined(ANALOG_JOYSTICK_ENABLE) && (defined(__AVR__) || defined(PROTOCOL_CHIBIOS))
+    int16_t axis_val = analogReadPin(joystick_axes[axis].input_pin);
+#else
+    // default to resting position
+    int16_t axis_val = joystick_axes[axis].mid_digit;
+#endif
+
+    // test the converted value against the lower range
+    int32_t ref        = joystick_axes[axis].mid_digit;
+    int32_t range      = joystick_axes[axis].min_digit;
+    int32_t ranged_val = ((axis_val - ref) * -JOYSTICK_RESOLUTION) / (range - ref);
+
+    if (ranged_val > 0) {
+        // the value is in the higher range
+        range      = joystick_axes[axis].max_digit;
+        ranged_val = ((axis_val - ref) * JOYSTICK_RESOLUTION) / (range - ref);
+    }
+
+    // clamp the result in the valid range
+    ranged_val = ranged_val < -JOYSTICK_RESOLUTION ? -JOYSTICK_RESOLUTION : ranged_val;
+    ranged_val = ranged_val > JOYSTICK_RESOLUTION ? JOYSTICK_RESOLUTION : ranged_val;
+
+    return ranged_val;
+}
+
+void joystick_read_axes() {
+#if JOYSTICK_AXES_COUNT > 0
+    for (int i = 0; i < JOYSTICK_AXES_COUNT; ++i) {
+        if (joystick_axes[i].input_pin == JS_VIRTUAL_AXIS) {
+            continue;
+        }
+
+        joystick_set_axis(i, joystick_read_axis(i));
+    }
+
+    joystick_flush();
+#endif
+}
+
+void joystick_set_axis(uint8_t axis, int16_t value) {
+    if (value != joystick_status.axes[axis]) {
+        joystick_status.axes[axis] = value;
+        joystick_status.status |= JS_UPDATED;
+    }
+}

quantum/joystick.h

@@ -1,3 +1,19 @@
+/* Copyright 2022
+ *
+ * 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
 
 #include <stdint.h>
@@ -54,7 +70,10 @@ typedef struct {
 
 extern joystick_config_t joystick_axes[JOYSTICK_AXES_COUNT];
 
-enum joystick_status { JS_INITIALIZED = 1, JS_UPDATED = 2 };
+enum joystick_status {
+    JS_INITIALIZED = 1,
+    JS_UPDATED,
+};
 
 typedef struct {
     uint8_t buttons[(JOYSTICK_BUTTON_COUNT - 1) / 8 + 1];
@@ -65,7 +84,14 @@ typedef struct {
 
 extern joystick_t joystick_status;
 
+void joystick_task(void);
 void joystick_flush(void);
 
 void register_joystick_button(uint8_t button);
 void unregister_joystick_button(uint8_t button);
+
+int16_t joystick_read_axis(uint8_t axis);
+void    joystick_read_axes(void);
+void    joystick_set_axis(uint8_t axis, int16_t value);
+
+void host_joystick_send(joystick_t *joystick);