1 /* Copyright (C) 2011-2014 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 -----
25 #include <Lib/MainLib.h>
29 #include <scan_loop.h>
30 #include <output_com.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 #if defined(_at90usb162_) || defined(_atmega32u4_) || defined(_at90usb646_) || defined(_at90usb1286_)
47 #define CPU_PRESCALE(n) (CLKPR = 0x80, CLKPR = (n))
52 // ----- Variables -----
54 // Timer Interrupt for flagging a send of the sampled key detection data to the USB host
55 uint16_t sendKeypressCounter = 0;
57 // Flag generated by the timer interrupt
58 volatile uint8_t sendKeypresses = 0;
62 // ----- Functions -----
64 inline void usbTimerSetup()
67 #if defined(_at90usb162_) || defined(_atmega32u4_) || defined(_at90usb646_) || defined(_at90usb1286_)
69 // Setup with 16 MHz clock
72 // Setup ISR Timer for flagging a kepress send to USB
73 // Set to 256 * 1024 (8 bit timer with Clock/1024 prescalar) timer
76 TIMSK0 = (1 << TOIE0);
79 #elif defined(_mk20dx128_) || defined(_mk20dx128vlf5_) || defined(_mk20dx256_)
80 // 48 MHz clock by default
82 // System Clock Gating Register Disable
83 SIM_SCGC6 |= SIM_SCGC6_PIT;
88 // Setup ISR Timer for flagging a kepress send to USB
89 // 1 ms / (1 / 48 MHz) - 1 = 47999 cycles -> 0xBB7F
90 PIT_LDVAL0 = 0x0000BB7F;
91 PIT_TCTRL0 = 0x3; // Enable Timer 0 interrupts, and Enable Timer 0
93 // Insert the required vector for Timer 0
94 NVIC_ENABLE_IRQ( IRQ_PIT_CH0 );
109 // Setup ISR Timer for flagging a kepress send to USB
112 // Main Detection Loop
118 // Acquire Key Indices
119 // Loop continuously until scan_loop returns 0
121 while ( Scan_loop() );
124 // Run Macros over Key Indices and convert to USB Keys
127 // Send keypresses over USB if the ISR has signalled that it's time
128 if ( !sendKeypresses )
134 // Clear sendKeypresses Flag
140 // ----- Interrupts -----
142 // USB Keyboard Data Send Counter Interrupt
143 #if defined(_at90usb162_) || defined(_atmega32u4_) || defined(_at90usb646_) || defined(_at90usb1286_) // AVR
144 ISR( TIMER0_OVF_vect )
145 #elif defined(_mk20dx128_) || defined(_mk20dx128vlf5_) || defined(_mk20dx256_) // ARM
149 sendKeypressCounter++;
150 if ( sendKeypressCounter > USB_TRANSFER_DIVIDER ) {
151 sendKeypressCounter = 0;
155 #if defined(_mk20dx128_) || defined(_mk20dx128vlf5_) || defined(_mk20dx256_) // ARM
156 // Clear the interrupt flag