Joystick.cpp

@@ -1,6 +1,9 @@
 #include "Joystick.h"
+#include <Mux.h>
 #include <Arduino.h>
 
+using namespace admux;
+
 bool operator ==(JoyReport a, JoyReport b){
   for (uint8_t i=0; i < JOYSTICK_NUM_AXES; i++) {
     if (a.axis[i] != b.axis[i]) return false;
@@ -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() {
@@ -32,6 +40,17 @@ void Joystick::Init() {
 }
 
 void Joystick::AddButton(uint8_t pin, ButtonType type, bool pullup) {
+  _BuildButton(pin, type, pullup);
+}
+
+void Joystick::AddMuxButton(uint8_t pin, uint8_t mux_id, uint8_t mux_channel, ButtonType type, bool pullup) {
+  Button *button = _BuildButton(pin, type, pullup);
+  button->mux = true;
+  button->mux_id = mux_id;
+  button->mux_channel = mux_channel;
+}
+
+Button* Joystick::_BuildButton(uint8_t pin, ButtonType type, bool pullup) {
   uint8_t mode;
   if (pullup) mode = INPUT_PULLUP;
   else mode = INPUT;
@@ -57,6 +76,8 @@ void Joystick::AddButton(uint8_t pin, ButtonType type, bool pullup) {
   _virtual_buttons += increment;
 
   if (type & _BUTTON_PULSED_TYPES) _have_pulsed_button = true;
+
+  return &button;
 }
 
 void Joystick::AddAxis(uint8_t pin) {
@@ -64,6 +85,16 @@ void Joystick::AddAxis(uint8_t pin) {
   _num_axes++;
 }
 
+uint8_t Joystick::AddMux(uint8_t signal_pin, Pinset addr_pins, bool pullup) {
+  uint8_t mux_id = _num_mux;
+  uint8_t mode = INPUT_PULLUP;
+  if (!pullup) mode = INPUT;
+  Mux mux(Pin(signal_pin, mode, PinType::Digital), addr_pins);
+  _mux[mux_id] = &mux;
+  _num_mux++;
+  return mux_id;
+}
+
 void Joystick::Update() {
   JoyReport oldReport = _joyReport;
   
@@ -138,6 +169,9 @@ 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

@@ -1,9 +1,12 @@
 #ifndef _JOYSTICK_H_
 #define _JOYSTICK_H_
 
+#include <Mux.h>
 #include <Arduino.h>
 #include <Bounce2.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
 // defining them *before* you include Joystick.h.
@@ -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);
@@ -45,23 +57,36 @@ class Joystick {
     Joystick(bool debug=false);
     void Init();
     void Update();
-    
+
+    // 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);
-    void AddAxis(uint8_t pin); // Axes don't actually work yet!
+    void AddMuxButton(uint8_t pin, uint8_t mux_id, uint8_t mux_channel, ButtonType type, bool pullup=true);
+
+    // 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, Pinset addr_pins, bool pullup=true);
     
-    // Public access to these functions is deprecated and they may become private in a future
-    // version. Prefer the above API instead.
+  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);
-    
+
+    Button* _BuildButton(uint8_t pin, ButtonType type, bool pullup);
+
     Button _buttons[JOYSTICK_NUM_BUTTONS];
     uint8_t _num_buttons;
     uint8_t _virtual_buttons; // a single user-defined button can have multiple virtual buttons.
@@ -72,6 +97,9 @@ 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. You'll need to `#include <Mux.h>` to access `admux::Pinset`. `AddMux()` 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`.

examples/basic/basic.ino

@@ -2,21 +2,33 @@
 // In this example, we have 3 toggle switches and 2 momentary pushbuttons.
 // Each button is configured in a different one of the available behaviors.
 
-#include <Bounce2.h>
 #include <Joystick.h>
 
 bool debug = false;
 Joystick joystick(debug);
 
 void setup() {
+  // momentary pushbutton #1
   joystick.AddButton(9, BUTTON_PASSTHRU);
+
+  // momentary pushbutton #2 - this one will toggle on or off each time it is pushed
   joystick.AddButton(10, BUTTON_LATCHED_MOMENTARY);
+
+  // a toggle switch that acts like a momentary button - every time it's toggled 'on' it briefly sends
+  // a keypresss
   joystick.AddButton(11, BUTTON_PULSED);
+
+  // like the above, but it sends its button press when toggled on *and* when toggled off
   joystick.AddButton(12, BUTTON_PULSED_DOUBLE_ACTION);
+
+  // again, similar to the above, but it sends two *different* button presses - 'on' will be one button, 'off' another.
   joystick.AddButton(13, BUTTON_PULSED_DOUBLE_ACTION_SPLIT);
+
+  // start up serial communication
   joystick.Init();
 }
 
 void loop() {
+  // check all the button states and send any changes
   joystick.Update();
 }

examples/multiplexer/Makefile

@@ -0,0 +1,8 @@
+TARGET_BOARD=arduino:avr:uno
+COM_PORT=/dev/ttyACM0
+
+build:
+	arduino-cli compile -b ${TARGET_BOARD}
+
+upload:
+	arduino-cli upload -b ${TARGET_BOARD} -p ${COM_PORT}

examples/multiplexer/multiplexer.ino

@@ -0,0 +1,50 @@
+// An example sketch using the joystick library, demonstrating multiplexer support
+// In this example, we have 21 buttons we want to attach.
+// Unfortunately, the Arduino Uno only has 17 pins we can use!
+// So we've added an 8-channel multiplexer, connected to pins A1-A5.
+//
+// Note: this may not be the best approach for this many simple buttons. Using an input matrix
+//       would require as few as 10 inputs in this scenario, for example. This is just a demo :)
+
+#include <Joystick.h>
+#include <Mux.h>
+
+bool debug = false;
+Joystick joystick(debug);
+
+void setup() {
+  // All of our digital pins and A0 are taken up with pushbuttons
+  joystick.AddButton(2, BUTTON_PASSTHRU);
+  joystick.AddButton(3, BUTTON_PASSTHRU);
+  joystick.AddButton(4, BUTTON_PASSTHRU);
+  joystick.AddButton(5, BUTTON_PASSTHRU);
+  joystick.AddButton(6, BUTTON_PASSTHRU);
+  joystick.AddButton(7, BUTTON_PASSTHRU);
+  joystick.AddButton(8, BUTTON_PASSTHRU);
+  joystick.AddButton(9, BUTTON_PASSTHRU);
+  joystick.AddButton(10, BUTTON_PASSTHRU);
+  joystick.AddButton(11, BUTTON_PASSTHRU);
+  joystick.AddButton(12, BUTTON_PASSTHRU);
+  joystick.AddButton(13, BUTTON_PASSTHRU);
+  joystick.AddButton(A0, BUTTON_PASSTHRU);
+
+  // to get more room for our inputs, we add an 8-bit multiplexer
+  uint8_t mux = joystick.AddMux(A1, admux::Pinset(A2, A3, A4, A5), 4);
+
+  // now we can add the rest of the buttons
+  joystick.AddMuxButton(A1, mux, 0, BUTTON_PASSTHRU);
+  joystick.AddMuxButton(A1, mux, 1, BUTTON_PASSTHRU);
+  joystick.AddMuxButton(A1, mux, 2, BUTTON_PASSTHRU);
+  joystick.AddMuxButton(A1, mux, 3, BUTTON_PASSTHRU);
+  joystick.AddMuxButton(A1, mux, 4, BUTTON_PASSTHRU);
+  joystick.AddMuxButton(A1, mux, 5, BUTTON_PASSTHRU);
+  joystick.AddMuxButton(A1, mux, 6, BUTTON_PASSTHRU);
+  joystick.AddMuxButton(A1, mux, 7, BUTTON_PASSTHRU);
+  
+  joystick.Init();
+}
+
+void loop() {
+  // check all the button states and send any changes
+  joystick.Update();
+}