main.cpp

00001 /**
00002  *
00003  *
00004  * PS/2 Code from : https://os.mbed.com/cookbook/PS2
00005  * Conversion code from: https://gist.github.com/Slumber86/4439a6a5f2fcb5ece61a5c24b962535d
00006  * https://github.com/keyboardio/KeyboardioHID/blob/master/src/BootKeyboard/BootKeyboard.cpp
00007  * Explantion of PS/2 protocol: https://web.archive.org/web/20070321032851/https://www.beyondlogic.org/keyboard/keybrd.htm
00008  * Explanation of keycodes of different layouts: http://www.quadibloc.com/comp/scan.htm
00009  * Source with LED command on arduino: https://playground.arduino.cc/PS2Keyboard/Cpp/
00010  */
00011 
00012 #include "mbed.h"
00013 #include "USBKeyboard.h"
00014 #include "PS2Keyboard.h"
00015 #include "Keymaps.h"
00016 
00017 DigitalOut myled2(LED2);
00018 DigitalOut myled4(LED4);
00019 PS2Keyboard ps2kb(p22, p23); //PS/2 keyboard (Clock, Data)
00020 USBKeyboard keyboard;
00021 LAYOUTS layo = LO_DE; //Layout of connected PS/2 keyboard, important only when additional keys are used
00022 bool ext, brk;
00023 int skip;
00024 uint8_t report[9]; //array with data for USB HID report
00025 Keymaps Kmap(layo, false); //keymap for normal keys
00026 Keymaps KmapE(layo, true); //keymap for keys with E0 prefix
00027 uint8_t leds;
00028 bool send_leds;
00029 
00030 
00031 void report_add(uint8_t k); //add USB keycode to report array
00032 void report_remove(uint8_t k); //remove USB keycode from report array
00033 
00034 int main()
00035 {
00036     myled2=1;
00037     PS2Keyboard::keyboard_event_t evt_kb;
00038     while (!keyboard.configured()) {    // wait until keyboard is configured
00039     }
00040     wait(1.0);
00041     myled2=0;
00042     myled4=1;
00043     while (1) {
00044         if (ps2kb.processing(&evt_kb)) {
00045             uint8_t k = evt_kb.scancode; //scancode of PS/2 keyboard
00046             uint8_t k2 = 0; //translated keycode in USB format
00047 
00048             if (k) {
00049                 if (skip) {
00050                     --skip;
00051                 } else {
00052                     if (k == 0xE0) { //special key, lookup in KE konversion table
00053                         ext = true;
00054                     } else if (k == 0xF0) { //breakcode, following scancode will be removed from report
00055                         brk = true;
00056                     } else if (k == 0xFA) { //acknowledgement from keyboard
00057                         if (send_leds) {
00058                             send_leds = false;
00059                             //send_msg(leds); //send LED status to keyboard, not functional
00060                         }
00061                     } else {
00062                         if (k == 0xE1) { //only one multibyte scancode uses this prefix
00063                             k2 = 72;
00064                             skip = 7; //following scancodes not nesessary for indentification, are skiped
00065                             brk = true; //no longpress of this key possible
00066                             report_add(k2);
00067                             keyboard.scanCodeRep(report);
00068                         } else {
00069                             k2 = ext ? KmapE.K[k] : Kmap.K[k]; // konvesion from PS/2 to USB HID keycode
00070                         }
00071 
00072                         if (k2) {
00073                             if (brk) {
00074                                 report_remove(k2);
00075                                 if (k2 == 83 || k2 == 71 || k2 == 57) { //keys relevant for keyboard LEDs
00076                                     send_leds = true;
00077                                     if (k2 == 83) {
00078                                         leds ^= 2;
00079                                     } else if (k2 == 71) {
00080                                         leds ^= 1;
00081                                     } else if (k2 == 57) {
00082                                         leds ^= 4;
00083                                     }
00084                                     //send_msg(0xED); //send LED status to keyboard, not functional
00085                                 }
00086                             } else {
00087                                 report_add(k2);
00088                             }
00089                             keyboard.scanCodeRep(report);
00090                             brk = false;
00091                             ext = false;
00092                         }
00093                     }
00094                 }
00095             }
00096         }
00097     }
00098 }
00099 
00100 
00101 void report_remove(uint8_t k)
00102 {
00103     uint8_t i;
00104     if (k >= 224) { //is modifier key
00105         report[1] &= ~(1 << (k - 224));
00106     } else {
00107         for (i = 3; i < 9; ++i) { //loop only normal key places
00108             if (report[i] == k) { //if key in report
00109                 report[i] = 0;
00110                 break;
00111             }
00112         }
00113     }
00114 }
00115 
00116 void report_add(uint8_t k)
00117 {
00118     uint8_t i;
00119     if (k >= 224) { //is modifier key
00120         report[1] |= 1 << (k - 224);
00121     } else if (report[3] != k && report[4] != k &&
00122                report[5] != k && report[6] != k &&
00123                report[7] != k && report[8] != k) { //not already set in report
00124         for (i = 3; i < 9; ++i) { //loop only normal key
00125             if (report[i] == 0) { //first free place is set
00126                 report[i] = k;
00127                 break;
00128             }
00129         }
00130     }
00131 }