Archived
1
0
This repo is archived. You can view files and clone it, but cannot push or open issues or pull requests.
controller/Output/pjrcUSB/arm/usb_keyboard.c

53 lines
1.2 KiB
C
Raw Normal View History

#include "usb_dev.h"
#include "usb_keyboard.h"
#include <Lib/USBLib.h>
#include <string.h> // for memcpy()
// Maximum number of transmit packets to queue so we don't starve other endpoints for memory
#define TX_PACKET_LIMIT 4
static uint8_t transmit_previous_timeout=0;
// When the PC isn't listening, how long do we wait before discarding data?
#define TX_TIMEOUT_MSEC 50
#if F_CPU == 96000000
#define TX_TIMEOUT (TX_TIMEOUT_MSEC * 596)
#elif F_CPU == 48000000
#define TX_TIMEOUT (TX_TIMEOUT_MSEC * 428)
#elif F_CPU == 24000000
#define TX_TIMEOUT (TX_TIMEOUT_MSEC * 262)
#endif
// send the contents of keyboard_keys and keyboard_modifier_keys
uint8_t usb_keyboard_send(void)
{
uint32_t wait_count=0;
usb_packet_t *tx_packet;
while (1) {
if (!usb_configuration) {
return -1;
}
if (usb_tx_packet_count(KEYBOARD_ENDPOINT) < TX_PACKET_LIMIT) {
tx_packet = usb_malloc();
if (tx_packet) break;
}
if (++wait_count > TX_TIMEOUT || transmit_previous_timeout) {
transmit_previous_timeout = 1;
return -1;
}
yield();
}
*(tx_packet->buf) = USBKeys_Modifiers;
*(tx_packet->buf + 1) = 0;
memcpy(tx_packet->buf + 2, USBKeys_Array, USB_MAX_KEY_SEND);
tx_packet->len = 8;
usb_tx(KEYBOARD_ENDPOINT, tx_packet);
return 0;
}