Joystick.cpp

@@ -1,5 +1,8 @@
 #include "Joystick.h"
 #include <Arduino.h>
+#include <Mux.h>
+
+using namespace admux;
 
 bool operator ==(JoyReport a, JoyReport b){
   for (uint8_t i=0; i < JOYSTICK_NUM_AXES; i++) {
@@ -19,11 +22,16 @@ Joystick::Joystick(bool debug) {
   _debug = debug;
   _virtual_buttons = 0;
   _num_axes = 0;
+  _num_mux = 0;
+  _num_buttons = 0;
   _have_pulsed_button = false;
 
   for (uint8_t i=0; i < JOYSTICK_NUM_AXES; i++) {
     _joyReport.axis[i] = 0;
   }
+  for (uint8_t i=0; i < JOYSTICK_NUM_BYTES; i++) {
+    _joyReport.button[i] = 0;
+  }
 }
 
 void Joystick::Init() {
@@ -64,6 +72,20 @@ void Joystick::AddAxis(uint8_t pin) {
   _num_axes++;
 }
 
+void Joystick::AddMux(uint8_t signal_pin, uint8_t addr_pins[], uint8_t addr_width, bool pullup=true) {
+  Pinset pins;
+  for (uint8_t i = 0; i < addr_width; i++) {
+    pins.pins[i] = addr_pins[i];
+  }
+  pins.m_size = addr_width;
+
+  uint8_t mode = INPUT_PULLUP;
+  if (!pullup) mode = INPUT;
+  Mux mux(Pin(signal_pin, mode, PinType::Digital), pins);
+  _mux[_num_mux] = mux;
+  _num_mux++;
+}
+
 void Joystick::Update() {
   JoyReport oldReport = _joyReport;
   
@@ -138,6 +160,9 @@ void Joystick::Write() {
 
 void Joystick::_UpdateButton(uint8_t button_num) {
   Button *button = &_buttons[button_num];
+  if (button->mux) {
+    _mux[button->mux_id].channel(button->mux_channel);
+  }
   bool changed = button->bouncer.update();
   if (!changed) return;
 

Joystick.h

@@ -3,6 +3,9 @@
 
 #include <Arduino.h>
 #include <Bounce2.h>
+#include <Mux.h>
+
+using namespace admux;
 
 // If you're using the arduino-big-joystick firmware, these numbers can't be
 // changed. If you're writing your own Report Descriptor, tune these to match by
@@ -15,6 +18,10 @@
 #endif
 #define JOYSTICK_NUM_BYTES (JOYSTICK_NUM_BUTTONS+7)/8
 
+#ifndef MAX_MUX
+#define MAX_MUX 3
+#endif
+
 enum ButtonType {
   BUTTON_PASSTHRU = 0x1, // always use the (debounced) absolute state of the input
   BUTTON_PULSED = 0x2, // on button press, send an on signal followed immediately by an off signal.
@@ -35,6 +42,11 @@ struct Button {
   uint8_t vbutton1; // only used by BUTTON_PULSED_DOUBLE_ACTION_SPLIT
   bool pressed = false; // only used by BUTTON_LATCHED_MOMENTARY
   bool inverted = false; // if true, send button press on release and vice versa.
+
+  // todo: this should probably be abstracted out from this struct...
+  bool mux;
+  uint8_t mux_id;
+  uint8_t mux_channel;
 };
 
 bool operator ==(JoyReport a, JoyReport b);
@@ -46,18 +58,28 @@ class Joystick {
     void Init();
     void Update();
 
-    void AddButton(uint8_t pin, ButtonType type, bool pullup=true);
-    void AddAxis(uint8_t pin); // Axes don't actually work yet!
+    // Add a button to the joystick.
+    // Button types are documented in the ButtonType enum.
+    // If `pullup` is true, your button should connect the pin to ground. (also be sure that your board supports INPUT_PULLUP on that pin)
+    // If `pullup` is false, your button should connect the pin to VCC.
+    // Mux parameters are ignored unless `mux` is true.
+    void AddButton(uint8_t pin, ButtonType type, bool pullup=true, bool mux=false, uint8_t mux_id = 0; uint8_t mux_channel = 0);
 
-    // Public access to these functions is deprecated and they may become private in a future
-    // version. Prefer the above API instead.
+    // Add an analog axis to the joystick. THIS METHOD IS NOT CURRENTLY TESTED OR SUPPORTED. It might work, but probably not.
+    void AddAxis(uint8_t pin);
+
+    // Add control for a multiplexer. To add a button that's connected via the multiplexer,
+    // pass the mux's signal pin as the pin parameter to AddButton(), along with the mux* parameters.
+    // mux_id is the array index of the mux (in the order you added them via AddMux())
+    uint8_t AddMux(uint8_t signal_pin, uint8_t addr_pins[], uint8_t addr_width);
+    
+  private:
     void SetAxis(uint8_t axis, int16_t value);
     void PressButton(uint8_t button);
     void ReleaseButton(uint8_t button);
     void ReleaseAllButtons();
     void Write();
 
-  private:
     void _ReleasePulsedButtons();
     void _UpdateButton(uint8_t index);
     void _UpdateAxis(uint8_t index);
@@ -72,6 +94,9 @@ class Joystick {
     
     JoyReport _joyReport;
     bool _debug;
+
+    Mux     _mux[MAX_MUX];
+    uint8_t _num_mux;
 };
 
 // Internal use only.

Readme.md

@@ -2,17 +2,28 @@
 This is a library that builds and sends USB HID Joystick reports, making it easy to build USB Joysticks with Arduino.
 
 ## Dependencies
-* Your Arduino's USB communication chip must be programmed with the arduino-big-joystick firmware (or similar). See <https://github.com/harlequin-tech/arduino-usb> for more info.
+* After uploading your sketch, your Arduino's USB communication chip will need to be programmed with the arduino-big-joystick firmware (or similar). See <https://github.com/harlequin-tech/arduino-usb> for more info.
 * The Bounce2 library, available at <https://github.com/thomasfredericks/Bounce2>.
+* The Analog-Digital Multiplexers library, available at <https://github.com/stechio/arduino-ad-mux-lib>.
 
 ## Installation
-1. Put the arduino-joystick directory into your Arduino libraries directory.
-2. Make sure Bounce2 is installed!
+1. Install dependencies as above, or if using `arduino-cli`, with:
+    arduino-cli lib install Bounce2
+    arduino-cli lib install "Analog-Digital Multiplexers"
+2. Put the arduino-joystick directory into your Arduino libraries directory.
 
 ## Usage
 1. In your arduino sketch, add the includes:
-    #include <Bounce2.h>
     #include <Joystick.h>
 2. Create a Joystick object:
-    Joystick joystick;
-3. Add buttons and axes in setup() with Joystick::AddButton(), and call Joystick::Update() in loop(). That's it!
+    Joystick joystick(true);
+3. Add buttons and axes in setup() with Joystick::AddButton(), and call Joystick::Update() in loop().
+4. Upload the sketch, connect to the serial monitor (at 115200 baud) and test the buttons.
+5. Set the joystick's `debug` parameter to `false` and re-upload the sketch. The arduino will NOT work in joystick mode with debug set to `true`!
+6. Flash the `arduino-big-joystick` firmware onto the USB Controller.
+
+### Advanced usage: multiplexers
+
+If you need more buttons than your board has pins, multiplexers (such as [this one](https://www.sparkfun.com/products/13906) and [this one](https://www.sparkfun.com/products/9056)) are a popular solution. This library supports multiplexers! To use them, you need to do some extra work.
+
+Call the `AddMux()` method and pass it the pins the multiplexer is connected to. It will return a `mux_id` for subsequently passing to `AddButton()`. The `pin` parameter for all multiplexed buttons should be the same as the multiplexer's `signal_pin`.