Hotboards_keypad.cpp

00001 /*
00002 ||
00003 || @file Hotboards_Keypad.h
00004 || @version 3.2
00005 || @ported by Diego (Hotboards)
00006 || This Keypad fork library allow to work with keyboard that
00007 || has physical pull-ups on columns (rather than rows)
00008 ||
00009 || Keypad library originaly develop by:
00010 || @author Mark Stanley, Alexander Brevig
00011 || @contact mstanley@technologist.com, alexanderbrevig@gmail.com
00012 ||
00013 || @description
00014 || | This library provides a simple interface for using matrix
00015 || | keypads. It supports multiple keypresses while maintaining
00016 || | backwards compatibility with the old single key library.
00017 || | It also supports user selectable pins and definable keymaps.
00018 || #
00019 ||
00020 || @license
00021 || | This library is free software; you can redistribute it and/or
00022 || | modify it under the terms of the GNU Lesser General Public
00023 || | License as published by the Free Software Foundation; version
00024 || | 2.1 of the License.
00025 || |
00026 || | This library is distributed in the hope that it will be useful,
00027 || | but WITHOUT ANY WARRANTY; without even the implied warranty of
00028 || | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00029 || | Lesser General Public License for more details.
00030 || |
00031 || | You should have received a copy of the GNU Lesser General Public
00032 || | License along with this library; if not, write to the Free Software
00033 || | Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
00034 || #
00035 ||
00036 */
00037 #include "Hotboards_keypad.h"
00038 
00039 #define bitRead( var, bit )           (((var) >> (bit)) & 0x01)
00040 #define bitWrite( var, bit, val )     (val) ? (var) |= (1<<(bit)) : (var) &= ~(1<<(bit))
00041 
00042 // <<constructor>> Allows custom keymap, pin configuration, and keypad sizes.
00043 Keypad::Keypad(char *userKeymap, DigitalInOut *row, DigitalInOut *col, uint8_t numRows, uint8_t numCols) {
00044     rowPins = row;
00045     columnPins = col;
00046     sizeKpd.rows = numRows;
00047     sizeKpd.columns = numCols;
00048 
00049     begin(userKeymap);
00050 
00051     setDebounceTime(10);
00052     setHoldTime(500);
00053     keypadEventListener = 0;
00054 
00055     startTime = 0;
00056     debounce.start();
00057     single_key = false;
00058 }
00059 
00060 // Let the user define a keymap - assume the same row/column count as defined in constructor
00061 void Keypad::begin(char *userKeymap) {
00062     keymap = userKeymap;
00063 }
00064 
00065 // Returns a single key only. Retained for backwards compatibility.
00066 char Keypad::getKey() {
00067     single_key = true;
00068 
00069     if (getKeys() && key[0].stateChanged && (key[0].kstate==PRESSED))
00070         return key[0].kchar;
00071 
00072     single_key = false;
00073 
00074     return NO_KEY;
00075 }
00076 
00077 // Populate the key list.
00078 bool Keypad::getKeys() {
00079     bool keyActivity = false;
00080 
00081     // Limit how often the keypad is scanned. This makes the loop() run 10 times as fast.
00082     if ( (debounce.read_ms()-startTime)>debounceTime ) {
00083         scanKeys();
00084         keyActivity = updateList();
00085         startTime = debounce.read_ms();
00086     }
00087 
00088     return keyActivity;
00089 }
00090 
00091 // Private : Hardware scan
00092 void Keypad::scanKeys() {
00093     // Re-intialize the row pins. Allows sharing these pins with other hardware.
00094     for (uint8_t c=0; c<sizeKpd.columns; c++) {
00095         columnPins[c].input();
00096     }
00097 
00098     // bitMap stores ALL the keys that are being pressed.
00099     for (uint8_t r=0; r<sizeKpd.rows; r++) {
00100         rowPins[r].output();
00101         rowPins[r].write( 0 );  // Begin column pulse output.
00102         for (uint8_t c=0; c<sizeKpd.columns; c++) {
00103             bitWrite(bitMap[c], r, !columnPins[c].read());  // keypress is active low so invert to high.
00104         }
00105         // Set pin to high impedance input. Effectively ends column pulse.
00106         rowPins[r].write( 1 );
00107         rowPins[r].input();
00108     }
00109 }
00110 
00111 // Manage the list without rearranging the keys. Returns true if any keys on the list changed state.
00112 bool Keypad::updateList() {
00113 
00114     bool anyActivity = false;
00115 
00116     // Delete any IDLE keys
00117     for (uint8_t i=0; i<LIST_MAX; i++) {
00118         if (key[i].kstate==IDLE) {
00119             key[i].kchar = NO_KEY;
00120             key[i].kcode = -1;
00121             key[i].stateChanged = false;
00122         }
00123     }
00124 
00125     // Add new keys to empty slots in the key list.
00126     for (uint8_t c=0; c<sizeKpd.columns; c++) {
00127         for (uint8_t r=0; r<sizeKpd.rows; r++) {
00128             bool button = bitRead(bitMap[r],c);
00129             char keyChar = keymap[c * sizeKpd.rows + r];
00130             int keyCode = r * sizeKpd.columns + c;
00131             int idx = findInList (keyCode);
00132             // Key is already on the list so set its next state.
00133             if (idx > -1)   {
00134                 nextKeyState(idx, button);
00135             }
00136             // Key is NOT on the list so add it.
00137             if ((idx == -1) && button) {
00138                 for (uint8_t i=0; i<LIST_MAX; i++) {
00139                     if (key[i].kchar==NO_KEY) {     // Find an empty slot or don't add key to list.
00140                         key[i].kchar = keyChar;
00141                         key[i].kcode = keyCode;
00142                         key[i].kstate = IDLE;       // Keys NOT on the list have an initial state of IDLE.
00143                         nextKeyState (i, button);
00144                         break;  // Don't fill all the empty slots with the same key.
00145                     }
00146                 }
00147             }
00148         }
00149     }
00150 
00151     // Report if the user changed the state of any key.
00152     for (uint8_t i=0; i<LIST_MAX; i++) {
00153         if (key[i].stateChanged) anyActivity = true;
00154     }
00155 
00156     return anyActivity;
00157 }
00158 
00159 // Private
00160 // This function is a state machine but is also used for debouncing the keys.
00161 void Keypad::nextKeyState(uint8_t idx, bool button) {
00162     key[idx].stateChanged = false;
00163 
00164     switch (key[idx].kstate) {
00165         case IDLE:
00166             if (button==CLOSED) {
00167                 transitionTo (idx, PRESSED);
00168                 holdTimer = debounce.read_ms(); }     // Get ready for next HOLD state.
00169             break;
00170         case PRESSED:
00171             if ((debounce.read_ms()-holdTimer)>holdTime)  // Waiting for a key HOLD...
00172                 transitionTo (idx, HOLD);
00173             else if (button==OPEN)              // or for a key to be RELEASED.
00174                 transitionTo (idx, RELEASED);
00175             break;
00176         case HOLD:
00177             if (button==OPEN)
00178                 transitionTo (idx, RELEASED);
00179             break;
00180         case RELEASED:
00181             transitionTo (idx, IDLE);
00182             break;
00183     }
00184 }
00185 
00186 // New in 2.1
00187 bool Keypad::isPressed(char keyChar) {
00188     for (uint8_t i=0; i<LIST_MAX; i++) {
00189         if ( key[i].kchar == keyChar ) {
00190             if ( (key[i].kstate == PRESSED) && key[i].stateChanged )
00191                 return true;
00192         }
00193     }
00194     return false;   // Not pressed.
00195 }
00196 
00197 // Search by character for a key in the list of active keys.
00198 // Returns -1 if not found or the index into the list of active keys.
00199 int Keypad::findInList (char keyChar) {
00200     for (uint8_t i=0; i<LIST_MAX; i++) {
00201         if (key[i].kchar == keyChar) {
00202             return i;
00203         }
00204     }
00205     return -1;
00206 }
00207 
00208 // Search by code for a key in the list of active keys.
00209 // Returns -1 if not found or the index into the list of active keys.
00210 int Keypad::findInList (int keyCode) {
00211     for (uint8_t i=0; i<LIST_MAX; i++) {
00212         if (key[i].kcode == keyCode) {
00213             return i;
00214         }
00215     }
00216     return -1;
00217 }
00218 
00219 // New in 2.0
00220 char Keypad::waitForKey() {
00221     char waitKey = NO_KEY;
00222     while( (waitKey = getKey()) == NO_KEY );    // Block everything while waiting for a keypress.
00223     return waitKey;
00224 }
00225 
00226 // Backwards compatibility function.
00227 KeyState Keypad::getState() {
00228     return key[0].kstate;
00229 }
00230 
00231 // The end user can test for any changes in state before deciding
00232 // if any variables, etc. needs to be updated in their code.
00233 bool Keypad::keyStateChanged() {
00234     return key[0].stateChanged;
00235 }
00236 
00237 // The number of keys on the key list, key[LIST_MAX], equals the number
00238 // of bytes in the key list divided by the number of bytes in a Key object.
00239 uint8_t Keypad::numKeys() {
00240     return sizeof(key)/sizeof(Key);
00241 }
00242 
00243 // Minimum debounceTime is 1 mS. Any lower *will* slow down the loop().
00244 void Keypad::setDebounceTime(uint debounce) {
00245     debounce<1 ? debounceTime=1 : debounceTime=debounce;
00246 }
00247 
00248 void Keypad::setHoldTime(uint hold) {
00249     holdTime = hold;
00250 }
00251 
00252 void Keypad::addEventListener(void (*listener)(char)){
00253     keypadEventListener = listener;
00254 }
00255 
00256 void Keypad::transitionTo(uint8_t idx, KeyState nextState) {
00257     key[idx].kstate = nextState;
00258     key[idx].stateChanged = true;
00259 
00260     // Sketch used the getKey() function.
00261     // Calls keypadEventListener only when the first key in slot 0 changes state.
00262     if (single_key)  {
00263         if ( (keypadEventListener!=NULL) && (idx==0) )  {
00264             keypadEventListener(key[0].kchar);
00265         }
00266     }
00267     // Sketch used the getKeys() function.
00268     // Calls keypadEventListener on any key that changes state.
00269     else {
00270         if (keypadEventListener!=NULL)  {
00271             keypadEventListener(key[idx].kchar);
00272         }
00273     }
00274 }
00275 
00276 /*
00277 || @changelog
00278 || | 3.1 2013-01-15 - Mark Stanley     : Fixed missing RELEASED & IDLE status when using a single key.
00279 || | 3.0 2012-07-12 - Mark Stanley     : Made library multi-keypress by default. (Backwards compatible)
00280 || | 3.0 2012-07-12 - Mark Stanley     : Modified pin functions to support Keypad_I2C
00281 || | 3.0 2012-07-12 - Stanley & Young  : Removed static variables. Fix for multiple keypad objects.
00282 || | 3.0 2012-07-12 - Mark Stanley     : Fixed bug that caused shorted pins when pressing multiple keys.
00283 || | 2.0 2011-12-29 - Mark Stanley     : Added waitForKey().
00284 || | 2.0 2011-12-23 - Mark Stanley     : Added the public function keyStateChanged().
00285 || | 2.0 2011-12-23 - Mark Stanley     : Added the private function scanKeys().
00286 || | 2.0 2011-12-23 - Mark Stanley     : Moved the Finite State Machine into the function getKeyState().
00287 || | 2.0 2011-12-23 - Mark Stanley     : Removed the member variable lastUdate. Not needed after rewrite.
00288 || | 1.8 2011-11-21 - Mark Stanley     : Added decision logic to compile WProgram.h or Arduino.h
00289 || | 1.8 2009-07-08 - Alexander Brevig : No longer uses arrays
00290 || | 1.7 2009-06-18 - Alexander Brevig : Every time a state changes the keypadEventListener will trigger, if set.
00291 || | 1.7 2009-06-18 - Alexander Brevig : Added setDebounceTime. setHoldTime specifies the amount of
00292 || |                                          microseconds before a HOLD state triggers
00293 || | 1.7 2009-06-18 - Alexander Brevig : Added transitionTo
00294 || | 1.6 2009-06-15 - Alexander Brevig : Added getState() and state variable
00295 || | 1.5 2009-05-19 - Alexander Brevig : Added setHoldTime()
00296 || | 1.4 2009-05-15 - Alexander Brevig : Added addEventListener
00297 || | 1.3 2009-05-12 - Alexander Brevig : Added lastUdate, in order to do simple debouncing
00298 || | 1.2 2009-05-09 - Alexander Brevig : Changed getKey()
00299 || | 1.1 2009-04-28 - Alexander Brevig : Modified API, and made variables private
00300 || | 1.0 2007-XX-XX - Mark Stanley : Initial Release
00301 || #
00302 */