Revision: 4365 Author: hans URL: http://bknr.net/trac/changeset/4365 documentation A trunk/projects/symbolics-keyboard/teensy-firmware/README.txt U trunk/projects/symbolics-keyboard/teensy-firmware/symbolics.c Added: trunk/projects/symbolics-keyboard/teensy-firmware/README.txt =================================================================== --- trunk/projects/symbolics-keyboard/teensy-firmware/README.txt (rev 0) +++ trunk/projects/symbolics-keyboard/teensy-firmware/README.txt 2009-04-07 11:47:42 UTC (rev 4365) @@ -0,0 +1,53 @@ +Symbolics keyboard adapter, based on Teensy keyboard example. + +The Symbolics keyboard acts as a shift register with 128 bits. Each +key is represented by one bit in the shift register. The hardware +interface consists of a clear line which is used to signal the +beginning of a read cycle, a clock line, and a data line. All signals +are active low. The keyboard changes the data line on the rising edge +of the clock. It should be read near the falling edge of the clock by +the host. + +The keyboard needs to be interfaced to the Teensy board as +follows. The wire colors specified are those used in the original +modular cable supplied with the keyboard: + +blue 5V +green GND +red D4 DIN +black D5 CLK +white D6 CLR + +The keyboard implements two locking functions, caps lock and mode +lock. Both of these are implemented as switches, not as buttons. +Host systems do not usually expect switches on keyboards, so +precautions must be taken to synchronize their state to the host's +state. + +The "Caps Lock" key is implemented so that it works as usual, i.e. it +is transmitted to the host as if it were a button. The host sends +back its caps lock state through the keyboard LEDs. Thus, the +controller firmware can synchronize the host's state with the state of +the caps lock switch on the keyboard. + +The "Mode Lock" key is used to switch the keyboard between the classic +Symbolics layout and a variant that assigns the modifier keys on the +right side of the space bar to be cursor keys. This mode is called +f_mode. + +The "Local" key is used as a modifier key to trigger functions in the +converter firmware. The following functions are implemented: + +Local-B boots the AVR into the boot loader so that it can be +reprogrammed through USB by the host. + +Local-V sends the Subversion revision number of this file to the host. + +Mapping of the symbolics key number to an USB key number is done +through the mapping table defined in the file keymap.inc. There are +two separate tables, one for normal mode and one for f_mode. The +mapping table is normally autogenerated by the keymap generation +program contained in make-keymap.lisp, but it can be manually edited +if no Lisp evironment is available. + +Author: Hans Huebner (hans.huebner@gmail.com). Property changes on: trunk/projects/symbolics-keyboard/teensy-firmware/README.txt ___________________________________________________________________ Name: svn:executable + * Modified: trunk/projects/symbolics-keyboard/teensy-firmware/symbolics.c =================================================================== --- trunk/projects/symbolics-keyboard/teensy-firmware/symbolics.c 2009-04-07 10:56:59 UTC (rev 4364) +++ trunk/projects/symbolics-keyboard/teensy-firmware/symbolics.c 2009-04-07 11:47:42 UTC (rev 4365) @@ -1,29 +1,16 @@ // -*- C++ -*- (this is really C) -// Symbolics keyboard adapter, based on Teensy keyboard example. +// -*- C++ -*- -// The Symbolics keyboard acts as a shift register with 128 bits. The -// hardware interface consists of a clear line which is used to signal -// the beginning of a read cycle, a clock line, and a data line. All -// signals are active low. The keyboard changes the data line on the -// rising edge of the clock. It should be read near the falling edge -// of the clock by the host. +// Symbolics keyboard to USB adapter -// The keyboard needs to be interfaced to the Teensy board as -// follows. The wire colors specified are those used in the original -// modular cable supplied with the keyboard: -// -// blue 5V -// green GND -// red D4 DIN -// black D5 CLK -// white D6 CLR +// See the README.txt file for documentation -// The keyboard implements two locking functions, caps lock and mode -// lock. Both of these are implemented as switches, not as buttons, -// so precautions must be made to synchronize their state to the -// host's caps lock state. +// Copyright 2009 by Hans Huebner (hans.huebner@gmail.com). +// Additional copyrights apply. +// This is the original copyright notice for this file: + /* Keyboard example for Teensy USB Development Board * http://www.pjrc.com/teensy/usb_keyboard.html * Copyright (c) 2008 PJRC.COM, LLC @@ -87,6 +74,8 @@ void init_keyboard_interface(void) { + // Initialize I/O ports used to interface to the keyboard + DDRD = MASK_CLOCK | MASK_CLEAR; PORTD = MASK_CLOCK | MASK_CLEAR | MASK_DIN; } @@ -94,30 +83,34 @@ void poll_keyboard(uint8_t* state) { - PORTD &= ~MASK_CLEAR; - _delay_us(10); - PORTD |= MASK_CLEAR; - _delay_us(100); - for (int i = 0; i < 16; i++) { - uint8_t buf = 0; - for (int j = 0; j < 8; j++) { - buf >>= 1; - PORTD &= ~MASK_CLOCK; - _delay_us(10); - PORTD |= MASK_CLOCK; - _delay_us(40); - if (!(PIND & MASK_DIN)) { - buf |= 0x80; - } + // Read the keyboard shift register into the memory region pointed + // to by state. + + PORTD &= ~MASK_CLEAR; + _delay_us(10); + PORTD |= MASK_CLEAR; + _delay_us(100); + for (int i = 0; i < 16; i++) { + uint8_t buf = 0; + for (int j = 0; j < 8; j++) { + buf >>= 1; + PORTD &= ~MASK_CLOCK; + _delay_us(10); + PORTD |= MASK_CLOCK; + _delay_us(40); + if (!(PIND & MASK_DIN)) { + buf |= 0x80; } - state[i] = buf; } + state[i] = buf; + } } void jump_to_loader(void) { // Jump to the HalfKay (or any other) boot loader + USBCON = 0; asm("jmp 0x3000"); } @@ -159,9 +152,11 @@ // Evaluate key press. switch (keyboard_keys[0]) { + case KEY_B: jump_to_loader(); break; + case KEY_V: report_version(); break; @@ -171,8 +166,8 @@ void send_keys(uint8_t* state) { - // A change of state has been detected by the main loop, report all - // currently pressed keys to the host. + // Report all currently pressed keys to the host. This function + // will be called when a change of state has been detected. uint8_t local = 0; uint8_t caps_lock_pressed = 0;