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 -----
25 #include <avr/interrupt.h>
32 #include "scan_loop.h"
33 #include "matrix_scan.h"
37 // ----- Defines -----
40 #define SAMPLE_THRESHOLD 110
41 #define MAX_SAMPLES 127 // Max is 127, reaching 128 is very bad
47 // Loop over all of the sampled keys of the given array
48 // If the number of samples is higher than the sample threshold, flag the high bit, clear otherwise
49 // This should be resetting VERY quickly, cutting off a potentially valid keypress is not an issue
50 #define DEBOUNCE_ASSESS(table,size) \
51 for ( uint8_t key = 1; key < size + 1; key++ ) \
52 table[key] = ( table[key] & ~(1 << 7) ) > SAMPLE_THRESHOLD ? (1 << 7) : 0x00
56 // ----- Variables -----
58 // Keeps track of the number of scans, so we only do a debounce assess when it would be valid (as it throws away data)
59 uint8_t scan_count = 0;
61 // This is where the matrix scan data is held, as well as debouncing is evaluated to, which (depending on the read value) is handled
62 // by the macro module
63 uint8_t KeyIndex_Array[KEYBOARD_SIZE + 1];
67 // ----- Functions -----
70 inline void scan_setup()
72 matrix_pinSetup( (uint8_t*)matrix_pinout );
75 // Main Detection Loop
76 inline uint8_t scan_loop()
78 // Check count to see if the sample threshold may have been reached, otherwise collect more data
79 if ( scan_count < MAX_SAMPLES )
81 matrix_scan( (uint8_t*)matrix_pinout, KeyIndex_Array );
83 // scanDual requires 2 passes, and thus needs more memory per matrix_scan pass
84 #if scanMode == scanDual
90 // Signal Main Detection Loop to continue scanning
94 // Reset Sample Counter
97 // Assess debouncing sample table
98 DEBOUNCE_ASSESS( KeyIndex_Array, KeyIndex_Size );
100 // Ready to allow for USB send