1 files changed, 76 insertions, 0 deletions
diff --git a/converter/ps2_usb/README.md b/converter/ps2_usb/README.md
new file mode 100644
index 0000000000..65e616efb1
--- /dev/null
+++ b/converter/ps2_usb/README.md
@@ -0,0 +1,76 @@
+PS/2 to USB keyboard converter
+==============================
+This firmware converts PS/2 keyboard protocol to USB and supports only Scan Code Set 2.
+
+
+PS/2 signal handling implementations
+------------------------------------
+Following three methods are used to implement PS/2 signal handling.
+
+### Simple and stupid busy-wait(ps2_busywait.c)
+    This is expected to implemented with portable C code for reference.
+### Interrupt driven(ps2_interrupt.c)
+    Uses pin interrupt to detect falling edge of clock line.
+### USART hardware module(ps2_usart.c)
+    Uses AVR USART engine to recevie PS/2 signal.
+
+To select method edit Makefile.
+
+
+Connect Wires
+-------------
+In case of Teensy2.0(ATMega32U4):
+
+1. Connect Vcc and GND.
+2. Connect Clock and Data line. 
+    - Busywait:    Clock is on PD5 and Data on PD2.
+    - Interrupt:   Clock is on PD1 and Data on PD2.
+    - USART:       Clock is on PD5 and Data on PD2.
+3. Optionally you need pull-up register. 1K-10K Ohm is OK.
+
+To change pin configuration edit config.h.
+
+
+Build Frimware
+--------------
+Just run `make`:
+
+    $ make
+
+To select keymap:
+
+    $ make KEYMAP=[plain|jis|spacefn|...]
+
+
+Keymap
+------
+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.
+
+
+V-USB Support
+-------------
+You can also use this converter on ATmega(168/328) with V-USB instead of Teensy.
+The converter on V-USB lacks some features for now: USB NKRO and System/Media control.
+
+Circuit:
+
+                    +---+   +---------------+
+    USB            GND  |   |   ATmega168   |
+    ===                 C3  |               |
+    5V <-------+--------+---|Vcc,AVCC       |        PS/2
+               R1           |               |        ====
+    D- <----+--+-----R2-----|INT1        RXD|------->DATA
+    D+ <----|---+----R3-----|INT0        XCK|------->CLOCK
+            Z1  Z2          |               |      ->5V
+    GND<----+---+--+--+-----|GND            |      ->GND
+                   |  |     |               |
+                   |  C2-+--|XTAL1          |
+                   |     X1 |               |
+                   +--C3-+--|XTAL2          |
+                            +---------------+
+    R1:     1.5K Ohm
+    R2,R3:  68 Ohm
+    Z1,Z2:  Zenner 3.6V
+    C1,C2:  22pF
+    C3:     0.1uF
+    X1:     Crystal 20MHz(16MHz/12MHz)