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/* Teensyduino Core Library
* http://www.pjrc.com/teensy/
* Copyright (c) 2017 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 "core_pins.h"
//#include "HardwareSerial.h"
#if defined(HAS_KINETIS_TSI) || defined(HAS_KINETIS_TSI_LITE)
#if defined(__MK20DX128__) || defined(__MK20DX256__)
// These settings give approx 0.02 pF sensitivity and 1200 pF range
// Lower current, higher number of scans, and higher prescaler
// increase sensitivity, but the trade-off is longer measurement
// time and decreased range.
#define CURRENT 2 // 0 to 15 - current to use, value is 2*(current+1)
#define NSCAN 9 // number of times to scan, 0 to 31, value is nscan+1
#define PRESCALE 2 // prescaler, 0 to 7 - value is 2^(prescaler+1)
static const uint8_t pin2tsi[] = {
//0 1 2 3 4 5 6 7 8 9
9, 10, 255, 255, 255, 255, 255, 255, 255, 255,
255, 255, 255, 255, 255, 13, 0, 6, 8, 7,
255, 255, 14, 15, 255, 12, 255, 255, 255, 255,
255, 255, 11, 5
};
#elif defined(__MK66FX1M0__)
#define NSCAN 9
#define PRESCALE 2
static const uint8_t pin2tsi[] = {
//0 1 2 3 4 5 6 7 8 9
9, 10, 255, 255, 255, 255, 255, 255, 255, 255,
255, 255, 255, 255, 255, 13, 0, 6, 8, 7,
255, 255, 14, 15, 255, 255, 255, 255, 255, 11,
12, 255, 255, 255, 255, 255, 255, 255, 255, 255
};
#elif defined(__MKL26Z64__)
#define NSCAN 9
#define PRESCALE 2
static const uint8_t pin2tsi[] = {
//0 1 2 3 4 5 6 7 8 9
9, 10, 255, 2, 3, 255, 255, 255, 255, 255,
255, 255, 255, 255, 255, 13, 0, 6, 8, 7,
255, 255, 14, 15, 255, 255, 255
};
#endif
// output is approx pF * 50
// time to measure 33 pF is approx 0.25 ms
// time to measure 1000 pF is approx 4.5 ms
int touchRead(uint8_t pin)
{
uint32_t ch;
if (pin >= NUM_DIGITAL_PINS) return 0;
ch = pin2tsi[pin];
if (ch == 255) return 0;
*portConfigRegister(pin) = PORT_PCR_MUX(0);
SIM_SCGC5 |= SIM_SCGC5_TSI;
#if defined(HAS_KINETIS_TSI)
TSI0_GENCS = 0;
TSI0_PEN = (1 << ch);
TSI0_SCANC = TSI_SCANC_REFCHRG(3) | TSI_SCANC_EXTCHRG(CURRENT);
TSI0_GENCS = TSI_GENCS_NSCN(NSCAN) | TSI_GENCS_PS(PRESCALE) | TSI_GENCS_TSIEN | TSI_GENCS_SWTS;
delayMicroseconds(10);
while (TSI0_GENCS & TSI_GENCS_SCNIP) ; // wait
delayMicroseconds(1);
return *((volatile uint16_t *)(&TSI0_CNTR1) + ch);
#elif defined(HAS_KINETIS_TSI_LITE)
TSI0_GENCS = TSI_GENCS_REFCHRG(4) | TSI_GENCS_EXTCHRG(3) | TSI_GENCS_PS(PRESCALE)
| TSI_GENCS_NSCN(NSCAN) | TSI_GENCS_TSIEN | TSI_GENCS_EOSF;
TSI0_DATA = TSI_DATA_TSICH(ch) | TSI_DATA_SWTS;
delayMicroseconds(10);
while (TSI0_GENCS & TSI_GENCS_SCNIP) ; // wait
delayMicroseconds(1);
return TSI0_DATA & 0xFFFF;
#endif
}
#else
int touchRead(uint8_t pin)
{
return 0; // no Touch sensing :(
}
#endif
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