Files
zOS/teensy3/usb_touch.c

142 lines
4.3 KiB
C

/* Teensyduino Core Library
* http://www.pjrc.com/teensy/
* Copyright (c) 2018 PJRC.COM, LLC.
*
* Permission is hereby granted, free of charge, to any person obtaining
* a copy of this software and associated documentation files (the
* "Software"), to deal in the Software without restriction, including
* without limitation the rights to use, copy, modify, merge, publish,
* distribute, sublicense, and/or sell copies of the Software, and to
* permit persons to whom the Software is furnished to do so, subject to
* the following conditions:
*
* 1. The above copyright notice and this permission notice shall be
* included in all copies or substantial portions of the Software.
*
* 2. If the Software is incorporated into a build system that allows
* selection among a list of target devices, then similar target
* devices manufactured by PJRC.COM must be included in the list of
* target devices and selectable in the same manner.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
* BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
* ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*/
#include "usb_dev.h"
#include "usb_touch.h"
#include "core_pins.h" // for millis()
#include "HardwareSerial.h"
#ifdef MULTITOUCH_INTERFACE // defined by usb_dev.h -> usb_desc.h
#if F_CPU >= 20000000
static uint8_t prev_id=0;
static uint8_t scan_index=0;
static uint8_t scan_count=0;
static uint8_t contactid[MULTITOUCH_FINGERS];
static uint8_t pressure[MULTITOUCH_FINGERS];
static uint16_t xpos[MULTITOUCH_FINGERS];
static uint16_t ypos[MULTITOUCH_FINGERS];
static uint16_t scan_timestamp;
void usb_touchscreen_press(uint8_t finger, uint32_t x, uint32_t y, uint32_t press)
{
if (finger >= MULTITOUCH_FINGERS) return;
if (press > 255) press = 255;
if (x > 32767) x = 32767;
if (y > 32767) y = 32767;
__disable_irq();
if (pressure[finger] == 0 && press > 0) {
// Begin a new finger touch, assign a
// new Contact Identifier (usage 0x51)
uint8_t id = prev_id + 1;
if (id == 0 || id > 127) id = 1;
prev_id = id;
contactid[finger] = (id << 1) | 1;
}
xpos[finger] = x;
ypos[finger] = y;
pressure[finger] = press;
__enable_irq();
}
// User should allow at least 12 ms after release before starting a
// new touch with press, in case the host's driver does not properly
// parse a change in contact identifier to mean a new touch.
void usb_touchscreen_release(uint8_t finger)
{
if (finger >= MULTITOUCH_FINGERS) return;
pressure[finger] = 0;
}
// touch report
// 0: contact id + on/off
// 1: pressure
// 2: X lsb
// 3: X msb
// 4: Y lsb
// 5: Y msb
// 6: scan time lsb
// 7: scan time msb
// Called by the start-of-frame interrupt.
//
void usb_touchscreen_update_callback(void)
{
if (scan_index == 0) {
if (usb_tx_packet_count(MULTITOUCH_ENDPOINT) > 1) {
// wait to begin another scan if if more than
// one prior packet remains to transmit
return;
}
scan_timestamp = millis() * 10;
scan_count = 0;
}
while (scan_index < MULTITOUCH_FINGERS) {
uint32_t press = pressure[scan_index];
uint32_t id = contactid[scan_index];
if (id) {
usb_packet_t *tx_packet;
tx_packet = usb_malloc();
if (tx_packet == NULL) return;
if (press == 0) {
// End a finger touch. One final packet sent
// with same Contact Identifier (usage 0x51)
// and Tip Switch (usage 0x42) = zero
id &= 0xFE;
contactid[scan_index] = 0;
}
*(tx_packet->buf + 0) = id;
*(tx_packet->buf + 1) = press;
*(tx_packet->buf + 2) = xpos[scan_index];
*(tx_packet->buf + 3) = xpos[scan_index] >> 8;
*(tx_packet->buf + 4) = ypos[scan_index];
*(tx_packet->buf + 5) = ypos[scan_index] >> 8;
*(tx_packet->buf + 6) = scan_timestamp;
*(tx_packet->buf + 7) = scan_timestamp >> 8;
tx_packet->len = 8;
usb_tx(MULTITOUCH_ENDPOINT, tx_packet);
scan_index++;
return;
}
scan_index++;
}
if (++scan_count >= MULTITOUCH_FINGERS) {
// when done early, wait to restart another scan
scan_index = 0;
}
}
#endif // F_CPU
#endif // MULTITOUCH_INTERFACE