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