135 lines
		
	
	
	
		
			3.9 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			135 lines
		
	
	
	
		
			3.9 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /* Copyright 2022
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|  *
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|  * This program is free software: you can redistribute it and/or modify
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|  * it under the terms of the GNU General Public License as published by
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|  * the Free Software Foundation, either version 2 of the License, or
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|  * (at your option) any later version.
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|  *
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|  * This program is distributed in the hope that it will be useful,
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|  * but WITHOUT ANY WARRANTY; without even the implied warranty of
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|  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
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|  * GNU General Public License for more details.
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|  *
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|  * You should have received a copy of the GNU General Public License
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|  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
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|  */
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| 
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| #include "joystick.h"
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| 
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| #include "analog.h"
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| #include "wait.h"
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| 
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| joystick_t joystick_state = {
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|     .buttons = {0},
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|     .axes =
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|         {
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| #if JOYSTICK_AXIS_COUNT > 0
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|             0
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| #endif
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|         },
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|     .dirty = false,
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| };
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| 
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| // array defining the reading of analog values for each axis
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| __attribute__((weak)) joystick_config_t joystick_axes[JOYSTICK_AXIS_COUNT] = {};
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| 
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| __attribute__((weak)) void joystick_task(void) {
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|     joystick_read_axes();
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| }
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| 
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| void joystick_flush(void) {
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|     if (joystick_state.dirty) {
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|         host_joystick_send(&joystick_state);
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|         joystick_state.dirty = false;
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|     }
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| }
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| 
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| void register_joystick_button(uint8_t button) {
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|     if (button >= JOYSTICK_BUTTON_COUNT) return;
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|     joystick_state.buttons[button / 8] |= 1 << (button % 8);
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|     joystick_state.dirty = true;
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|     joystick_flush();
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| }
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| 
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| void unregister_joystick_button(uint8_t button) {
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|     if (button >= JOYSTICK_BUTTON_COUNT) return;
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|     joystick_state.buttons[button / 8] &= ~(1 << (button % 8));
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|     joystick_state.dirty = true;
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|     joystick_flush();
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| }
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| 
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| int16_t joystick_read_axis(uint8_t axis) {
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|     if (axis >= JOYSTICK_AXIS_COUNT) return 0;
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| 
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|     // disable pull-up resistor
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|     writePinLow(joystick_axes[axis].input_pin);
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| 
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|     // if pin was a pull-up input, we need to uncharge it by turning it low
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|     // before making it a low input
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|     setPinOutput(joystick_axes[axis].input_pin);
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| 
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|     wait_us(10);
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| 
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|     if (joystick_axes[axis].output_pin != JS_VIRTUAL_AXIS) {
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|         setPinOutput(joystick_axes[axis].output_pin);
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|         writePinHigh(joystick_axes[axis].output_pin);
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|     }
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| 
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|     if (joystick_axes[axis].ground_pin != JS_VIRTUAL_AXIS) {
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|         setPinOutput(joystick_axes[axis].ground_pin);
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|         writePinLow(joystick_axes[axis].ground_pin);
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|     }
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| 
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|     wait_us(10);
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| 
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|     setPinInput(joystick_axes[axis].input_pin);
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| 
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|     wait_us(10);
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| 
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| #if defined(ANALOG_JOYSTICK_ENABLE) && (defined(__AVR__) || defined(PROTOCOL_CHIBIOS))
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|     int16_t axis_val = analogReadPin(joystick_axes[axis].input_pin);
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| #else
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|     // default to resting position
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|     int16_t axis_val = joystick_axes[axis].mid_digit;
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| #endif
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| 
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|     // test the converted value against the lower range
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|     int32_t ref        = joystick_axes[axis].mid_digit;
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|     int32_t range      = joystick_axes[axis].min_digit;
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|     int32_t ranged_val = ((axis_val - ref) * -JOYSTICK_MAX_VALUE) / (range - ref);
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| 
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|     if (ranged_val > 0) {
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|         // the value is in the higher range
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|         range      = joystick_axes[axis].max_digit;
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|         ranged_val = ((axis_val - ref) * JOYSTICK_MAX_VALUE) / (range - ref);
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|     }
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| 
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|     // clamp the result in the valid range
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|     ranged_val = ranged_val < -JOYSTICK_MAX_VALUE ? -JOYSTICK_MAX_VALUE : ranged_val;
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|     ranged_val = ranged_val > JOYSTICK_MAX_VALUE ? JOYSTICK_MAX_VALUE : ranged_val;
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| 
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|     return ranged_val;
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| }
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| 
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| void joystick_read_axes(void) {
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| #if JOYSTICK_AXIS_COUNT > 0
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|     for (int i = 0; i < JOYSTICK_AXIS_COUNT; ++i) {
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|         if (joystick_axes[i].input_pin == JS_VIRTUAL_AXIS) {
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|             continue;
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|         }
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| 
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|         joystick_set_axis(i, joystick_read_axis(i));
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|     }
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| 
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|     joystick_flush();
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| #endif
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| }
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| 
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| void joystick_set_axis(uint8_t axis, int16_t value) {
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|     if (axis >= JOYSTICK_AXIS_COUNT) return;
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| 
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|     if (value != joystick_state.axes[axis]) {
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|         joystick_state.axes[axis] = value;
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|         joystick_state.dirty      = true;
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|     }
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| }
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