Gets potentiometer and button reading from a joystick (https://proto-pic.co.uk/thumb-joystick-analogue/)
Dependents: L2_SpaceInvaders 6-Joystick
Joystick.cpp@1:78d3e8b50d19, 2016-05-02 (annotated)
- Committer:
- avi23
- Date:
- Mon May 02 16:27:49 2016 +0000
- Revision:
- 1:78d3e8b50d19
- Parent:
- 0:56a82b52e0d4
- Child:
- 2:c9f2a9e2f304
Documented using Doxygen
Who changed what in which revision?
User | Revision | Line number | New contents of line |
---|---|---|---|
avi23 | 1:78d3e8b50d19 | 1 | /** |
avi23 | 1:78d3e8b50d19 | 2 | @file Joystick.cpp |
avi23 | 1:78d3e8b50d19 | 3 | |
avi23 | 1:78d3e8b50d19 | 4 | @brief Member functions implementations |
avi23 | 1:78d3e8b50d19 | 5 | |
avi23 | 1:78d3e8b50d19 | 6 | */ |
avi23 | 0:56a82b52e0d4 | 7 | #include "Joystick.h" |
avi23 | 0:56a82b52e0d4 | 8 | #include "mbed.h" |
avi23 | 0:56a82b52e0d4 | 9 | |
avi23 | 0:56a82b52e0d4 | 10 | Joystick::Joystick(PinName x_axis_pin, PinName y_axis_pin, PinName button_pin) { |
avi23 | 0:56a82b52e0d4 | 11 | x_axis_ = new AnalogIn(x_axis_pin); |
avi23 | 0:56a82b52e0d4 | 12 | y_axis_ = new AnalogIn(y_axis_pin); |
avi23 | 0:56a82b52e0d4 | 13 | button_ = new InterruptIn(button_pin); |
avi23 | 0:56a82b52e0d4 | 14 | button_debounce_ = new Timeout(); |
avi23 | 0:56a82b52e0d4 | 15 | } |
avi23 | 0:56a82b52e0d4 | 16 | |
avi23 | 0:56a82b52e0d4 | 17 | Joystick::~Joystick() { |
avi23 | 0:56a82b52e0d4 | 18 | delete x_axis_; |
avi23 | 0:56a82b52e0d4 | 19 | delete y_axis_; |
avi23 | 0:56a82b52e0d4 | 20 | delete button_; |
avi23 | 0:56a82b52e0d4 | 21 | delete button_debounce_; |
avi23 | 0:56a82b52e0d4 | 22 | } |
avi23 | 0:56a82b52e0d4 | 23 | |
avi23 | 0:56a82b52e0d4 | 24 | void Joystick::init() { |
avi23 | 0:56a82b52e0d4 | 25 | //Sets up the button ISR |
avi23 | 0:56a82b52e0d4 | 26 | button_->mode(PullDown); |
avi23 | 0:56a82b52e0d4 | 27 | button_->rise(this, &Joystick::button_isr); |
avi23 | 0:56a82b52e0d4 | 28 | |
avi23 | 0:56a82b52e0d4 | 29 | //Initalises the vairables and flags |
avi23 | 0:56a82b52e0d4 | 30 | x_offset_ = 0; |
avi23 | 0:56a82b52e0d4 | 31 | y_offset_ = 0; |
avi23 | 0:56a82b52e0d4 | 32 | g_button_flag_ = false; |
avi23 | 0:56a82b52e0d4 | 33 | g_button_debounce_flag_ = false; |
avi23 | 0:56a82b52e0d4 | 34 | |
avi23 | 0:56a82b52e0d4 | 35 | //Samples the joystick 5 times and takes an average to get the offset |
avi23 | 0:56a82b52e0d4 | 36 | float x_sum = 0; |
avi23 | 0:56a82b52e0d4 | 37 | float y_sum = 0; |
avi23 | 0:56a82b52e0d4 | 38 | |
avi23 | 0:56a82b52e0d4 | 39 | for (int i = 0; i < 5; ++i) { |
avi23 | 0:56a82b52e0d4 | 40 | x_sum += x_axis_->read(); |
avi23 | 0:56a82b52e0d4 | 41 | y_sum += y_axis_->read(); |
avi23 | 0:56a82b52e0d4 | 42 | } |
avi23 | 0:56a82b52e0d4 | 43 | |
avi23 | 0:56a82b52e0d4 | 44 | x_offset_ = 0.5f - x_sum/5.0f; |
avi23 | 0:56a82b52e0d4 | 45 | y_offset_ = 0.5f - y_sum/5.0f; |
avi23 | 0:56a82b52e0d4 | 46 | } |
avi23 | 0:56a82b52e0d4 | 47 | |
avi23 | 0:56a82b52e0d4 | 48 | float Joystick::GetXValue() { |
avi23 | 0:56a82b52e0d4 | 49 | |
avi23 | 0:56a82b52e0d4 | 50 | float x_sum = 0; |
avi23 | 0:56a82b52e0d4 | 51 | //Iterates 5 times and calculates an average |
avi23 | 0:56a82b52e0d4 | 52 | for (int i = 0; i < 5; ++i) { |
avi23 | 0:56a82b52e0d4 | 53 | x_sum += x_axis_->read(); |
avi23 | 0:56a82b52e0d4 | 54 | } |
avi23 | 0:56a82b52e0d4 | 55 | |
avi23 | 0:56a82b52e0d4 | 56 | float x_value = x_sum/5.0f + x_offset_; |
avi23 | 0:56a82b52e0d4 | 57 | |
avi23 | 0:56a82b52e0d4 | 58 | //Caps the value for the POT between 0 and 1 |
avi23 | 0:56a82b52e0d4 | 59 | if (x_value < 0.0f) { |
avi23 | 0:56a82b52e0d4 | 60 | return 0; |
avi23 | 0:56a82b52e0d4 | 61 | } else if (x_value > 1.0f) { |
avi23 | 0:56a82b52e0d4 | 62 | return 1; |
avi23 | 0:56a82b52e0d4 | 63 | } else { |
avi23 | 0:56a82b52e0d4 | 64 | return x_value; |
avi23 | 0:56a82b52e0d4 | 65 | } |
avi23 | 0:56a82b52e0d4 | 66 | } |
avi23 | 0:56a82b52e0d4 | 67 | |
avi23 | 0:56a82b52e0d4 | 68 | float Joystick::GetYValue() { |
avi23 | 0:56a82b52e0d4 | 69 | |
avi23 | 0:56a82b52e0d4 | 70 | float y_sum = 0; |
avi23 | 0:56a82b52e0d4 | 71 | //Iterates 5 times and calculates an average |
avi23 | 0:56a82b52e0d4 | 72 | for (int i = 0; i < 5; ++i) { |
avi23 | 0:56a82b52e0d4 | 73 | y_sum += y_axis_->read(); |
avi23 | 0:56a82b52e0d4 | 74 | } |
avi23 | 0:56a82b52e0d4 | 75 | |
avi23 | 0:56a82b52e0d4 | 76 | float y_value = y_sum/5.0f + y_offset_; |
avi23 | 0:56a82b52e0d4 | 77 | |
avi23 | 0:56a82b52e0d4 | 78 | //Caps the value for the POT between 0 and 1 |
avi23 | 0:56a82b52e0d4 | 79 | if (y_value < 0.0f) { |
avi23 | 0:56a82b52e0d4 | 80 | return 0; |
avi23 | 0:56a82b52e0d4 | 81 | } else if (y_value > 1.0f) { |
avi23 | 0:56a82b52e0d4 | 82 | return 1; |
avi23 | 0:56a82b52e0d4 | 83 | } else { |
avi23 | 0:56a82b52e0d4 | 84 | return y_value; |
avi23 | 0:56a82b52e0d4 | 85 | } |
avi23 | 0:56a82b52e0d4 | 86 | } |
avi23 | 0:56a82b52e0d4 | 87 | |
avi23 | 0:56a82b52e0d4 | 88 | int Joystick::get_button_flag() { |
avi23 | 0:56a82b52e0d4 | 89 | return g_button_flag_; |
avi23 | 0:56a82b52e0d4 | 90 | } |
avi23 | 0:56a82b52e0d4 | 91 | |
avi23 | 0:56a82b52e0d4 | 92 | void Joystick::set_button_flag(bool value) { |
avi23 | 0:56a82b52e0d4 | 93 | g_button_flag_ = value; |
avi23 | 0:56a82b52e0d4 | 94 | } |
avi23 | 0:56a82b52e0d4 | 95 | |
avi23 | 0:56a82b52e0d4 | 96 | void Joystick::button_isr() { |
avi23 | 0:56a82b52e0d4 | 97 | if (!g_button_debounce_flag_) { |
avi23 | 0:56a82b52e0d4 | 98 | g_button_flag_ = true; |
avi23 | 0:56a82b52e0d4 | 99 | g_button_debounce_flag_ = true; |
avi23 | 0:56a82b52e0d4 | 100 | |
avi23 | 0:56a82b52e0d4 | 101 | //Sets up the debounce ticker to fire in 0.2s |
avi23 | 0:56a82b52e0d4 | 102 | button_debounce_->attach(this, &Joystick::button_debounce_isr, 0.2); |
avi23 | 0:56a82b52e0d4 | 103 | } |
avi23 | 0:56a82b52e0d4 | 104 | } |
avi23 | 0:56a82b52e0d4 | 105 | |
avi23 | 0:56a82b52e0d4 | 106 | void Joystick::button_debounce_isr() { |
avi23 | 0:56a82b52e0d4 | 107 | g_button_debounce_flag_ = false; |
avi23 | 0:56a82b52e0d4 | 108 | } |