From 9be1f999357edd37658c301d9dd5aaa1d8db26a7 Mon Sep 17 00:00:00 2001 From: px4dev Date: Mon, 31 Dec 2012 19:41:18 -0800 Subject: [PATCH] Add trivial ADC support to PX4IO. --- apps/px4io/adc.c | 163 +++++++++++++++++++++++++++++++++++++++++++++ apps/px4io/px4io.h | 6 ++ 2 files changed, 169 insertions(+) create mode 100644 apps/px4io/adc.c diff --git a/apps/px4io/adc.c b/apps/px4io/adc.c new file mode 100644 index 0000000000..62ff0b1f19 --- /dev/null +++ b/apps/px4io/adc.c @@ -0,0 +1,163 @@ +/**************************************************************************** + * + * Copyright (C) 2012 PX4 Development Team. All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in + * the documentation and/or other materials provided with the + * distribution. + * 3. Neither the name PX4 nor the names of its contributors may be + * used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS + * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE + * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, + * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, + * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS + * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED + * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN + * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE + * POSSIBILITY OF SUCH DAMAGE. + * + ****************************************************************************/ + +/** + * @file adc.c + * + * Simple ADC support for PX4IO on STM32. + */ +#include +#include + +#include +#include +#include + +#include +#include + +#define DEBUG +#include "px4io.h" + +/* + * Register accessors. + * For now, no reason not to just use ADC1. + */ +#define REG(_reg) (*(volatile uint32_t *)(STM32_ADC1_BASE + _reg)) + +#define rSR REG(STM32_ADC_SR_OFFSET) +#define rCR1 REG(STM32_ADC_CR1_OFFSET) +#define rCR2 REG(STM32_ADC_CR2_OFFSET) +#define rSMPR1 REG(STM32_ADC_SMPR1_OFFSET) +#define rSMPR2 REG(STM32_ADC_SMPR2_OFFSET) +#define rJOFR1 REG(STM32_ADC_JOFR1_OFFSET) +#define rJOFR2 REG(STM32_ADC_JOFR2_OFFSET) +#define rJOFR3 REG(STM32_ADC_JOFR3_OFFSET) +#define rJOFR4 REG(STM32_ADC_JOFR4_OFFSET) +#define rHTR REG(STM32_ADC_HTR_OFFSET) +#define rLTR REG(STM32_ADC_LTR_OFFSET) +#define rSQR1 REG(STM32_ADC_SQR1_OFFSET) +#define rSQR2 REG(STM32_ADC_SQR2_OFFSET) +#define rSQR3 REG(STM32_ADC_SQR3_OFFSET) +#define rJSQR REG(STM32_ADC_JSQR_OFFSET) +#define rJDR1 REG(STM32_ADC_JDR1_OFFSET) +#define rJDR2 REG(STM32_ADC_JDR2_OFFSET) +#define rJDR3 REG(STM32_ADC_JDR3_OFFSET) +#define rJDR4 REG(STM32_ADC_JDR4_OFFSET) +#define rDR REG(STM32_ADC_DR_OFFSET) + +perf_counter_t adc_perf; + +int +adc_init(void) +{ + adc_perf = perf_alloc(PC_ELAPSED, "adc"); + + /* do calibration if supported */ +#ifdef ADC_CR2_CAL + rCR2 |= ADC_CR2_RSTCAL; + up_udelay(1); + if (rCR2 & ADC_CR2_RSTCAL) + return -1; + rCR2 |= ADC_CR2_CAL; + up_udelay(100); + if (rCR2 & ADC_CR2_CAL) + return -1; +#endif + + /* arbitrarily configure all channels for 55 cycle sample time */ + rSMPR1 = 0b00000011011011011011011011011011; + rSMPR2 = 0b00011011011011011011011011011011; + + /* XXX for F2/4, might want to select 12-bit mode? */ + rCR1 = 0; + + /* enable the temperature sensor / Vrefint channel if supported*/ + rCR2 = +#ifdef ADC_CR2_TSVREFE + /* enable the temperature sensor in CR2 */ + ADC_CR2_TSVREFE | +#endif + 0; + +#ifdef ADC_CCR_TSVREFE + /* enable temperature sensor in CCR */ + rCCR = ADC_CCR_TSVREFE; +#endif + + /* configure for a single-channel sequence */ + rSQR1 = 0; + rSQR2 = 0; + rSQR3 = 0; /* will be updated with the channel each tick */ + + /* power-cycle the ADC and turn it on */ + rCR2 &= ~ADC_CR2_ADON; + up_udelay(10); + rCR2 |= ADC_CR2_ADON; + up_udelay(10); + rCR2 |= ADC_CR2_ADON; + up_udelay(10); + + return 0; +} + +uint16_t +adc_measure(unsigned channel) +{ + perf_begin(adc_perf); + + /* clear any previous EOC */ + if (rSR & ADC_SR_EOC) + rSR &= ~ADC_SR_EOC; + + /* run a single conversion right now - should take about 60 cycles (a few microseconds) max */ + rSQR3 = channel; + rCR2 |= ADC_CR2_ADON; + + /* wait for the conversion to complete */ + hrt_abstime now = hrt_absolute_time(); + while (!(rSR & ADC_SR_EOC)) { + + /* never spin forever - this will give a bogus result though */ + if ((hrt_absolute_time() - now) > 1000) { + debug("adc timeout"); + break; + } + } + + /* read the result and clear EOC */ + uint16_t result = rDR; + + perf_end(adc_perf); + return result; +} \ No newline at end of file diff --git a/apps/px4io/px4io.h b/apps/px4io/px4io.h index 45b7cf847a..6221b08f24 100644 --- a/apps/px4io/px4io.h +++ b/apps/px4io/px4io.h @@ -160,6 +160,12 @@ extern void safety_init(void); */ extern void comms_main(void) __attribute__((noreturn)); +/* + * Sensors/misc inputs + */ +extern int adc_init(void); +extern uint16_t adc_measure(unsigned channel); + /* * R/C receiver handling. */