1 /* Teensyduino Core Library
2 * http://www.pjrc.com/teensy/
3 * Copyright (c) 2013 PJRC.COM, LLC.
4 * Modifications by Jacob Alexander 2013-2014
6 * Permission is hereby granted, free of charge, to any person obtaining
7 * a copy of this software and associated documentation files (the
8 * "Software"), to deal in the Software without restriction, including
9 * without limitation the rights to use, copy, modify, merge, publish,
10 * distribute, sublicense, and/or sell copies of the Software, and to
11 * permit persons to whom the Software is furnished to do so, subject to
12 * the following conditions:
14 * 1. The above copyright notice and this permission notice shall be
15 * included in all copies or substantial portions of the Software.
17 * 2. If the Software is incorporated into a build system that allows
18 * selection among a list of target devices, then similar target
19 * devices manufactured by PJRC.COM must be included in the list of
20 * target devices and selectable in the same manner.
22 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
23 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
24 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
25 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
26 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
27 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
28 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
32 // ----- Includes -----
35 #include <string.h> // for memcpy()
38 #include <Lib/OutputLib.h>
43 #include "usb_keyboard.h"
47 // ----- Defines -----
49 // Maximum number of transmit packets to queue so we don't starve other endpoints for memory
50 #define TX_PACKET_LIMIT 4
52 // When the PC isn't listening, how long do we wait before discarding data?
53 #define TX_TIMEOUT_MSEC 50
56 #define TX_TIMEOUT (TX_TIMEOUT_MSEC * 596)
57 #elif F_CPU == 48000000
58 #define TX_TIMEOUT (TX_TIMEOUT_MSEC * 428)
59 #elif F_CPU == 24000000
60 #define TX_TIMEOUT (TX_TIMEOUT_MSEC * 262)
65 // ----- Variables -----
67 static uint8_t transmit_previous_timeout = 0;
71 // ----- Functions -----
73 // send the contents of keyboard_keys and keyboard_modifier_keys
74 void usb_keyboard_send()
76 uint32_t wait_count = 0;
77 usb_packet_t *tx_packet;
81 if ( !usb_configuration )
83 erro_print("USB not configured...");
86 if ( usb_tx_packet_count(KEYBOARD_ENDPOINT) < TX_PACKET_LIMIT )
88 tx_packet = usb_malloc();
92 if ( ++wait_count > TX_TIMEOUT || transmit_previous_timeout )
94 transmit_previous_timeout = 1;
95 warn_print("USB Transmit Timeout...");
102 *(tx_packet->buf) = USBKeys_Modifiers;
103 *(tx_packet->buf + 1) = 0;
104 memcpy( tx_packet->buf + 2, USBKeys_Keys, USB_BOOT_MAX_KEYS );
108 usb_tx( KEYBOARD_ENDPOINT, tx_packet );
109 USBKeys_Changed = USBKeyChangeState_None;