1 /* Copyright (C) 2011 by Jacob Alexander
3 * Permission is hereby granted, free of charge, to any person obtaining a copy
4 * of this software and associated documentation files (the "Software"), to deal
5 * in the Software without restriction, including without limitation the rights
6 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
7 * copies of the Software, and to permit persons to whom the Software is
8 * furnished to do so, subject to the following conditions:
10 * The above copyright notice and this permission notice shall be included in
11 * all copies or substantial portions of the Software.
13 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
14 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
15 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
16 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
17 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
18 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
22 // ----- Includes -----
26 #include <avr/interrupt.h>
30 #include <scan_loop.h>
38 // ----- Defines -----
40 // Verified Keypress Defines
41 #define USB_TRANSFER_DIVIDER 10 // 1024 == 1 Send of keypresses per second, 1 == 1 Send of keypresses per ~1 millisecond
46 #define CPU_PRESCALE(n) (CLKPR = 0x80, CLKPR = (n))
50 // ----- Variables -----
52 // Timer Interrupt for flagging a send of the sampled key detection data to the USB host
53 uint16_t sendKeypressCounter = 0;
55 // Flag generated by the timer interrupt
56 volatile uint8_t sendKeypresses = 0;
60 // ----- Functions -----
62 // Initial Pin Setup, make sure they are sane
63 inline void pinSetup(void)
66 // For each pin, 0=input, 1=output
67 #if defined(__AVR_AT90USB1286__)
77 // Setting pins to either high or pull-up resistor
78 #if defined(__AVR_AT90USB1286__)
90 // Setup with 16 MHz clock
100 // Setup ISR Timer for flagging a kepress send to USB
101 // Set to 256 * 1024 (8 bit timer with Clock/1024 prescalar) timer
104 TIMSK0 = (1 << TOIE0);
106 // Main Detection Loop
107 uint8_t ledTimer = 15; // Enable LED for a short time
110 // Setup the scanning module
115 // Acquire Key Indices
116 // Loop continuously until scan_loop returns 0
118 while ( scan_loop() );
121 // Run Macros over Key Indices and convert to USB Keys
124 // Send keypresses over USB if the ISR has signalled that it's time
125 if ( !sendKeypresses )
131 // Clear sendKeypresses Flag
134 // Indicate Error, if valid
135 errorLED( ledTimer );
141 // Loop should never get here (indicate error)
144 // HID Debug Error message
145 erro_print("Detection loop error, this is very bad...bug report!");
149 // USB Keyboard Data Send Counter Interrupt
150 ISR( TIMER0_OVF_vect )
152 sendKeypressCounter++;
153 if ( sendKeypressCounter > USB_TRANSFER_DIVIDER ) {
154 sendKeypressCounter = 0;