1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
|
# Joystick :id=joystick
This feature provides game controller input as a joystick device supporting up to 6 axes and 32 buttons. Axes can be read either from an [ADC-capable input pin](adc_driver.md), or can be virtual, so that its value is provided by your code.
An analog device such as a [potentiometer](https://en.wikipedia.org/wiki/Potentiometer) found on an analog joystick's axes is based on a voltage divider, where adjusting the movable wiper controls the output voltage which can then be read by the microcontroller's ADC.
## Usage :id=usage
Add the following to your `rules.mk`:
```make
JOYSTICK_ENABLE = yes
```
By default the joystick driver is `analog`, but you can change this with:
```make
JOYSTICK_DRIVER = digital
```
## Configuration :id=configuration
By default, two axes and eight buttons are defined, with a reported resolution of 8 bits (-127 to +127). This can be changed in your `config.h`:
```c
// Min 0, max 32
#define JOYSTICK_BUTTON_COUNT 16
// Min 0, max 6: X, Y, Z, Rx, Ry, Rz
#define JOYSTICK_AXIS_COUNT 3
// Min 8, max 16
#define JOYSTICK_AXIS_RESOLUTION 10
```
?> You must define at least one button or axis. Also note that the maximum ADC resolution of the supported AVR MCUs is 10-bit, and 12-bit for most STM32 MCUs.
### Axes :id=axes
When defining axes for your joystick, you must provide a definition array typically in your `keymap.c`.
For instance, the below example configures two axes. The X axis is read from the `A4` pin. With the default axis resolution of 8 bits, the range of values between 900 and 575 are scaled to -127 through 0, and values 575 to 285 are scaled to 0 through 127. The Y axis is configured as a virtual axis, and its value is not read from any pin. Instead, the user must update the axis value programmatically.
```c
joystick_config_t joystick_axes[JOYSTICK_AXIS_COUNT] = {
JOYSTICK_AXIS_IN(A4, 900, 575, 285),
JOYSTICK_AXIS_VIRTUAL
};
```
Axes can be configured using one of the following macros:
* `JOYSTICK_AXIS_IN(input_pin, low, rest, high)`
The ADC samples the provided pin. `low`, `high` and `rest` correspond to the minimum, maximum, and resting (or centered) analog values of the axis, respectively.
* `JOYSTICK_AXIS_IN_OUT(input_pin, output_pin, low, rest, high)`
Same as `JOYSTICK_AXIS_IN()`, but the provided `output_pin` will be pulled high before `input_pin` is read.
* `JOYSTICK_AXIS_IN_OUT_GROUND(input_pin, output_pin, ground_pin, low, rest, high)`
Same as `JOYSTICK_AXIS_IN_OUT()`, but the provided `ground_pin` will be pulled low before reading from `input_pin`.
* `JOYSTICK_AXIS_VIRTUAL`
No ADC reading is performed. The value should be provided by user code.
The `low` and `high` values can be swapped to effectively invert the axis.
#### Virtual Axes :id=virtual-axes
The following example adjusts two virtual axes (X and Y) based on keypad presses, with `KC_P0` as a precision modifier:
```c
joystick_config_t joystick_axes[JOYSTICK_AXIS_COUNT] = {
JOYSTICK_AXIS_VIRTUAL, // x
JOYSTICK_AXIS_VIRTUAL // y
};
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) {
int16_t precision_val = axis_val;
if (precision) {
precision_val -= precision_mod;
}
switch (keycode) {
case KC_P8:
joystick_set_axis(1, record->event.pressed ? -precision_val : 0);
return false;
case KC_P2:
joystick_set_axis(1, record->event.pressed ? precision_val : 0);
return false;
case KC_P4:
joystick_set_axis(0, record->event.pressed ? -precision_val : 0);
return false;
case KC_P6:
joystick_set_axis(0, record->event.pressed ? precision_val : 0);
return false;
case KC_P0:
precision = record->event.pressed;
return false;
}
return true;
}
```
## Keycodes :id=keycodes
|Key |Aliases|Description|
|-----------------------|-------|-----------|
|`QK_JOYSTICK_BUTTON_0` |`JS_0` |Button 0 |
|`QK_JOYSTICK_BUTTON_1` |`JS_1` |Button 1 |
|`QK_JOYSTICK_BUTTON_2` |`JS_2` |Button 2 |
|`QK_JOYSTICK_BUTTON_3` |`JS_3` |Button 3 |
|`QK_JOYSTICK_BUTTON_4` |`JS_4` |Button 4 |
|`QK_JOYSTICK_BUTTON_5` |`JS_5` |Button 5 |
|`QK_JOYSTICK_BUTTON_6` |`JS_6` |Button 6 |
|`QK_JOYSTICK_BUTTON_7` |`JS_7` |Button 7 |
|`QK_JOYSTICK_BUTTON_8` |`JS_8` |Button 8 |
|`QK_JOYSTICK_BUTTON_9` |`JS_9` |Button 9 |
|`QK_JOYSTICK_BUTTON_10`|`JS_10`|Button 10 |
|`QK_JOYSTICK_BUTTON_11`|`JS_11`|Button 11 |
|`QK_JOYSTICK_BUTTON_12`|`JS_12`|Button 12 |
|`QK_JOYSTICK_BUTTON_13`|`JS_13`|Button 13 |
|`QK_JOYSTICK_BUTTON_14`|`JS_14`|Button 14 |
|`QK_JOYSTICK_BUTTON_15`|`JS_15`|Button 15 |
|`QK_JOYSTICK_BUTTON_16`|`JS_16`|Button 16 |
|`QK_JOYSTICK_BUTTON_17`|`JS_17`|Button 17 |
|`QK_JOYSTICK_BUTTON_18`|`JS_18`|Button 18 |
|`QK_JOYSTICK_BUTTON_19`|`JS_19`|Button 19 |
|`QK_JOYSTICK_BUTTON_20`|`JS_20`|Button 20 |
|`QK_JOYSTICK_BUTTON_21`|`JS_21`|Button 21 |
|`QK_JOYSTICK_BUTTON_22`|`JS_22`|Button 22 |
|`QK_JOYSTICK_BUTTON_23`|`JS_23`|Button 23 |
|`QK_JOYSTICK_BUTTON_24`|`JS_24`|Button 24 |
|`QK_JOYSTICK_BUTTON_25`|`JS_25`|Button 25 |
|`QK_JOYSTICK_BUTTON_26`|`JS_26`|Button 26 |
|`QK_JOYSTICK_BUTTON_27`|`JS_27`|Button 27 |
|`QK_JOYSTICK_BUTTON_28`|`JS_28`|Button 28 |
|`QK_JOYSTICK_BUTTON_29`|`JS_29`|Button 29 |
|`QK_JOYSTICK_BUTTON_30`|`JS_30`|Button 30 |
|`QK_JOYSTICK_BUTTON_31`|`JS_31`|Button 31 |
## API :id=api
### `struct joystick_t` :id=api-joystick-t
Contains the state of the joystick.
#### Members :id=api-joystick-t-members
- `uint8_t buttons[]`
A bit-packed array containing the joystick button states. The size is calculated as `(JOYSTICK_BUTTON_COUNT - 1) / 8 + 1`.
- `int16_t axes[]`
An array of analog values for each defined axis.
- `bool dirty`
Whether the current state needs to be sent to the host.
---
### `struct joystick_config_t` :id=api-joystick-config-t
Describes a single axis.
#### Members :id=api-joystick-config-t-members
- `pin_t output_pin`
A pin to set as output high when reading the analog value, or `JS_VIRTUAL_AXIS`.
- `pin_t input_pin`
The pin to read the analog value from, or `JS_VIRTUAL_AXIS`.
- `pin_t ground_pin`
A pin to set as output low when reading the analog value, or `JS_VIRTUAL_AXIS`.
- `uint16_t min_digit`
The minimum analog value.
- `uint16_t mid_digit`
The resting or midpoint analog value.
- `uint16_t max_digit`
The maximum analog value.
---
### `void joystick_flush(void)` :id=api-joystick-flush
Send the joystick report to the host, if it has been marked as dirty.
---
### `void register_joystick_button(uint8_t button)` :id=api-register-joystick-button
Set the state of a button, and flush the report.
#### Arguments :id=api-register-joystick-button-arguments
- `uint8_t button`
The index of the button to press, from 0 to 31.
---
### `void unregister_joystick_button(uint8_t button)` :id=api-unregister-joystick-button
Reset the state of a button, and flush the report.
#### Arguments :id=api-unregister-joystick-button-arguments
- `uint8_t button`
The index of the button to release, from 0 to 31.
---
### `int16_t joystick_read_axis(uint8_t axis)` :id=api-joystick-read-axis
Sample and process the analog value of the given axis.
#### Arguments :id=api-joystick-read-axis-arguments
- `uint8_t axis`
The axis to read.
#### Return Value :id=api-joystick-read-axis-return
A signed 16-bit integer, where 0 is the resting or mid point.
### `void joystick_set_axis(uint8_t axis, int16_t value)` :id=api-joystick-set-axis
Set the value of the given axis.
#### Arguments :id=api-joystick-set-axis-arguments
- `uint8_t axis`
The axis to set the value of.
- `int16_t value`
The value to set.
|
