converter/ps2_usb/README.md

   1 PS/2 to USB keyboard converter
   2 ==============================
   3 This firmware converts PS/2 keyboard protocol to USB and supports only Scan Code Set 2.
   4
   5
   6 PS/2 signal handling implementations
   7 ------------------------------------
   8 Following three methods are used to implement PS/2 signal handling.
   9
  10 ### Simple and stupid busy-wait(ps2_busywait.c)
  11     This is expected to implemented with portable C code for reference.
  12 ### Interrupt driven(ps2_interrupt.c)
  13     Uses pin interrupt to detect falling edge of clock line.
  14 ### USART hardware module(ps2_usart.c)
  15     Uses AVR USART engine to recevie PS/2 signal.
  16
  17 To select method edit Makefile.
  18
  19
  20 Connect Wires
  21 -------------
  22 In case of Teensy2.0(ATMega32U4):
  23
  24 1. Connect Vcc and GND.
  25 2. Connect Clock and Data line.
  26     - Busywait:    Clock is on PD5 and Data on PD2.
  27     - Interrupt:   Clock is on PD1 and Data on PD2.
  28     - USART:       Clock is on PD5 and Data on PD2.
  29 3. Optionally you need pull-up register. 1K-10K Ohm is OK.
  30
  31 To change pin configuration edit config.h.
  32
  33
  34 Build Frimware
  35 --------------
  36 Just run `make`:
  37
  38     $ make
  39
  40 To select keymap:
  41
  42     $ make KEYMAP=[plain|jis|spacefn|...]
  43
  44
  45 Keymap
  46 ------
  47 Several version of keymap are available in advance but you are recommended to define your favorite layout yourself. To define your own keymap create file named `keymap_<name>.c` and see keymap document(you can find in top README.md) and existent keymap files.
  48
  49
  50 V-USB Support
  51 -------------
  52 You can also use this converter on ATmega(168/328) with V-USB instead of Teensy.
  53 The converter on V-USB lacks some features for now: USB NKRO and System/Media control.
  54
  55 Circuit:
  56
  57                     +---+   +---------------+
  58     USB            GND  |   |   ATmega168   |
  59     ===                 C3  |               |
  60     5V <-------+--------+---|Vcc,AVCC       |        PS/2
  61                R1           |               |        ====
  62     D- <----+--+-----R2-----|INT1        RXD|------->DATA
  63     D+ <----|---+----R3-----|INT0        XCK|------->CLOCK
  64             Z1  Z2          |               |      ->5V
  65     GND<----+---+--+--+-----|GND            |      ->GND
  66                    |  |     |               |
  67                    |  C2-+--|XTAL1          |
  68                    |     X1 |               |
  69                    +--C3-+--|XTAL2          |
  70                             +---------------+
  71     R1:     1.5K Ohm
  72     R2,R3:  68 Ohm
  73     Z1,Z2:  Zenner 3.6V
  74     C1,C2:  22pF
  75     C3:     0.1uF
  76     X1:     Crystal 20MHz(16MHz/12MHz)