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Commit 8697e9aa authored by cnlohr's avatar cnlohr
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Move touch to header.

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examples/cap_touch_adc/cap_touch_adc.c
+ 1
− 122
View file @ 8697e9aa
......@@ -21,101 +21,7 @@
#include "ch32v003fun.h"
#include <stdio.h>
#define ADC_SAMPLE_TIME 2 // Tricky: Don't change this without a lot of experimentation.
#define MAX_SCALECHECK 4
// Can either be 0 or 1.
// If 0: Measurement low and rises high. So more pressed is smaller number.
// If 1: Higher number = harder press. Good to pair with TOUCH_FLAT.
// If you are doing more prox, use mode 0, otherwise, use mode 1.
#define TOUCH_SLOPE 1
// If you set this to 1, it will glitch the line, so it will only read
// anything reasonable if the capacitance can overcome that initial spike.
// Typically, it seems if you use this you probbly don't need to do
// any pre-use calibration.
#define TOUCH_FLAT 0
void InitTouchADC( )
{
// ADCCLK = 24 MHz => RCC_ADCPRE = 0: divide sys clock by 2
RCC->CFGR0 &= ~(0x1F<<11);
// Set up single conversion on chl 2
ADC1->RSQR1 = 0;
ADC1->RSQR2 = 0;
// turn on ADC and set rule group to sw trig
ADC1->CTLR2 |= ADC_ADON | ADC_EXTSEL;
// Reset calibration
ADC1->CTLR2 |= ADC_RSTCAL;
while(ADC1->CTLR2 & ADC_RSTCAL);
// Calibrate
ADC1->CTLR2 |= ADC_CAL;
while(ADC1->CTLR2 & ADC_CAL);
}
// Run from RAM to get even more stable timing.
// This function call takes about 8.1uS to execute.
uint32_t ReadTouchPin( GPIO_TypeDef * io, int portpin, int adcno, int iterations ) __attribute__((noinline, section(".srodata")));
uint32_t ReadTouchPin( GPIO_TypeDef * io, int portpin, int adcno, int iterations )
{
uint32_t ret = 0;
ADC1->RSQR3 = adcno;
ADC1->SAMPTR2 = ADC_SAMPLE_TIME<<(3*adcno);
uint32_t CFGBASE = io->CFGLR & (~(0xf<<(4*portpin)));
uint32_t CFGFLOAT = ((GPIO_CFGLR_IN_PUPD)<<(4*portpin)) | CFGBASE;
uint32_t CFGDRIVE = (GPIO_CFGLR_OUT_2Mhz_PP)<<(4*portpin) | CFGBASE;
// If we run multiple times with slightly different wait times, we can
// reduce the impact of the ADC's DNL.
#if TOUCH_FLAT == 1
#define RELEASEIO io->OUTDR = 1<<(portpin+16*TOUCH_SLOPE); io->CFGLR = CFGFLOAT;
#else
#define RELEASEIO io->CFGLR = CFGFLOAT; io->OUTDR = 1<<(portpin+16*TOUCH_SLOPE);
#endif
#define INNER_LOOP( n ) \
{ \
/* Only lock IRQ for a very narrow window. */ \
__disable_irq(); \
\
/* Tricky - we start the ADC BEFORE we transition the pin. By doing \
this We are catching it onthe slope much more effectively. */ \
ADC1->CTLR2 = ADC_SWSTART | ADC_ADON | ADC_EXTSEL; \
\
ADD_N_NOPS( n ) \
\
RELEASEIO \
\
/* Sampling actually starts here, somewhere, so we can let other \
interrupts run */ \
__enable_irq(); \
while(!(ADC1->STATR & ADC_EOC)); \
io->CFGLR = CFGDRIVE; \
io->OUTDR = 1<<(portpin+(16*(1-TOUCH_SLOPE))); \
ret += ADC1->RDATAR; \
}
int i;
for( i = 0; i < iterations; i++ )
{
// Wait a variable amount of time based on loop iteration, in order
// to get a variety of RC points and minimize DNL.
INNER_LOOP( 0 );
INNER_LOOP( 2 );
INNER_LOOP( 4 );
}
return ret;
}
#include "ch32v003_touch.h"
int main()
{
......@@ -133,8 +39,6 @@ int main()
{
uint32_t sum[8] = { 0 };
int j;
uint32_t start = SysTick->CNT;
// Sampling all touch pads, 3x should take 6030 cycles, and runs at about 8kHz
......@@ -156,28 +60,3 @@ int main()
}
}
/*
* MIT License
*
* Copyright (c) 2023 Valve Corporation
*
* 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:
*
* The above copyright notice and this permission notice shall be included in all
* copies or substantial portions of the Software.
*
* 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.
*/
extralibs/ch32v003_touch.h 0 → 100644
+ 147
− 0
View file @ 8697e9aa
#ifndef _CH32V003_TOUCH_H
#define _CH32V003_TOUCH_H
/** ADC-based Capactive Touch Control.
see cap_touch_adc.c for an example.
// Enable GPIOD, C and ADC
RCC->APB2PCENR |= RCC_APB2Periph_GPIOA | RCC_APB2Periph_GPIOD | RCC_APB2Periph_GPIOC | RCC_APB2Periph_ADC1;
InitTouchADC();
// Then do this any time you want to read some touches.
sum[0] += ReadTouchPin( GPIOA, 2, 0, iterations );
sum[1] += ReadTouchPin( GPIOA, 1, 1, iterations );
sum[2] += ReadTouchPin( GPIOC, 4, 2, iterations );
sum[3] += ReadTouchPin( GPIOD, 2, 3, iterations );
sum[4] += ReadTouchPin( GPIOD, 3, 4, iterations );
sum[5] += ReadTouchPin( GPIOD, 5, 5, iterations );
sum[6] += ReadTouchPin( GPIOD, 6, 6, iterations );
sum[7] += ReadTouchPin( GPIOD, 4, 7, iterations );
*/
#define TOUCH_ADC_SAMPLE_TIME 2 // Tricky: Don't change this without a lot of experimentation.
// Can either be 0 or 1.
// If 0: Measurement low and rises high. So more pressed is smaller number.
// If 1: Higher number = harder press. Good to pair with TOUCH_FLAT.
// If you are doing more prox, use mode 0, otherwise, use mode 1.
#define TOUCH_SLOPE 1
// If you set this to 1, it will glitch the line, so it will only read
// anything reasonable if the capacitance can overcome that initial spike.
// Typically, it seems if you use this you probbly don't need to do
// any pre-use calibration.
#define TOUCH_FLAT 0
static void InitTouchADC( );
void InitTouchADC( )
{
// ADCCLK = 24 MHz => RCC_ADCPRE = 0: divide sys clock by 2
RCC->CFGR0 &= ~(0x1F<<11);
// Set up single conversion on chl 2
ADC1->RSQR1 = 0;
ADC1->RSQR2 = 0;
// turn on ADC and set rule group to sw trig
ADC1->CTLR2 |= ADC_ADON | ADC_EXTSEL;
// Reset calibration
ADC1->CTLR2 |= ADC_RSTCAL;
while(ADC1->CTLR2 & ADC_RSTCAL);
// Calibrate
ADC1->CTLR2 |= ADC_CAL;
while(ADC1->CTLR2 & ADC_CAL);
}
// Run from RAM to get even more stable timing.
// This function call takes about 8.1uS to execute.
static uint32_t ReadTouchPin( GPIO_TypeDef * io, int portpin, int adcno, int iterations ) __attribute__((noinline, section(".srodata")));
uint32_t ReadTouchPin( GPIO_TypeDef * io, int portpin, int adcno, int iterations )
{
uint32_t ret = 0;
ADC1->RSQR3 = adcno;
ADC1->SAMPTR2 = TOUCH_ADC_SAMPLE_TIME<<(3*adcno);
uint32_t CFGBASE = io->CFGLR & (~(0xf<<(4*portpin)));
uint32_t CFGFLOAT = ((GPIO_CFGLR_IN_PUPD)<<(4*portpin)) | CFGBASE;
uint32_t CFGDRIVE = (GPIO_CFGLR_OUT_2Mhz_PP)<<(4*portpin) | CFGBASE;
// If we run multiple times with slightly different wait times, we can
// reduce the impact of the ADC's DNL.
#if TOUCH_FLAT == 1
#define RELEASEIO io->OUTDR = 1<<(portpin+16*TOUCH_SLOPE); io->CFGLR = CFGFLOAT;
#else
#define RELEASEIO io->CFGLR = CFGFLOAT; io->OUTDR = 1<<(portpin+16*TOUCH_SLOPE);
#endif
#define INNER_LOOP( n ) \
{ \
/* Only lock IRQ for a very narrow window. */ \
__disable_irq(); \
\
/* Tricky - we start the ADC BEFORE we transition the pin. By doing \
this We are catching it onthe slope much more effectively. */ \
ADC1->CTLR2 = ADC_SWSTART | ADC_ADON | ADC_EXTSEL; \
\
ADD_N_NOPS( n ) \
\
RELEASEIO \
\
/* Sampling actually starts here, somewhere, so we can let other \
interrupts run */ \
__enable_irq(); \
while(!(ADC1->STATR & ADC_EOC)); \
io->CFGLR = CFGDRIVE; \
io->OUTDR = 1<<(portpin+(16*(1-TOUCH_SLOPE))); \
ret += ADC1->RDATAR; \
}
int i;
for( i = 0; i < iterations; i++ )
{
// Wait a variable amount of time based on loop iteration, in order
// to get a variety of RC points and minimize DNL.
INNER_LOOP( 0 );
INNER_LOOP( 2 );
INNER_LOOP( 4 );
}
return ret;
}
#endif
/*
* MIT License
*
* Copyright (c) 2023 Valve Corporation
*
* 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:
*
* The above copyright notice and this permission notice shall be included in all
* copies or substantial portions of the Software.
*
* 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.
*/
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