236 lines
10 KiB
C
236 lines
10 KiB
C
/*
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* This file is part of the MicroPython project, http://micropython.org/
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*
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* The MIT License (MIT)
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*
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* Copyright (c) 2017 Dan Halbert for Adafruit Industries
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*
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* Permission is hereby granted, free of charge, to any person obtaining a copy
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* of this software and associated documentation files (the "Software"), to deal
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* in the Software without restriction, including without limitation the rights
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* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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* copies of the Software, and to permit persons to whom the Software is
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* furnished to do so, subject to the following conditions:
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*
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* The above copyright notice and this permission notice shall be included in
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* all copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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* THE SOFTWARE.
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*/
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/*
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* Includes code from ASF sample code adc_temp.h and adc_temp.c,
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* and so includes this license:
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*
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* Copyright (C) 2015 Atmel Corporation. All rights reserved.
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*
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* License
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions are met:
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*
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* 1. Redistributions of source code must retain the above copyright notice,
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* this list of conditions and the following disclaimer.
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*
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* 2. Redistributions in binary form must reproduce the above copyright notice,
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* this list of conditions and the following disclaimer in the documentation
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* and/or other materials provided with the distribution.
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*
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* 3. The name of Atmel may not be used to endorse or promote products derived
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* from this software without specific prior written permission.
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*
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* 4. This software may only be redistributed and used in connection with an
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* Atmel microcontroller product.
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*
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* THIS SOFTWARE IS PROVIDED BY ATMEL "AS IS" AND ANY EXPRESS OR IMPLIED
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* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
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* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT ARE
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* EXPRESSLY AND SPECIFICALLY DISCLAIMED. IN NO EVENT SHALL ATMEL BE LIABLE FOR
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* ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
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* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
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* ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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* POSSIBILITY OF SUCH DAMAGE.
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*/
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#include "common-hal/microcontroller/Processor.h"
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// Don't reorder these includes because they are dependencies of adc_feature.h.
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// They should really be included by adc_feature.h.
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#include <compiler.h>
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#include "asf/sam0/drivers/system/clock/gclk.h"
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#include "asf/sam0/utils/cmsis/samd21/include/component/adc.h"
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#include "asf/sam0/drivers/adc/adc_sam_d_r/adc_feature.h"
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#include "asf/sam0/drivers/adc/adc.h"
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#define ADC_TEMP_SAMPLE_LENGTH 4
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#define INT1V_VALUE_FLOAT 1.0
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#define INT1V_DIVIDER_1000 1000.0
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#define ADC_12BIT_FULL_SCALE_VALUE_FLOAT 4095.0
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typedef struct nvm_calibration_data_t {
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float tempR; // Production Room temperature
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float tempH; // Production Hot temperature
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float INT1VR; // Room temp 2's complement of the internal 1V reference value
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float INT1VH; // Hot temp 2's complement of the internal 1V reference value
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uint16_t ADCR; // Production Room temperature ADC value
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uint16_t ADCH; // Production Hot temperature ADC value
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float VADCR; // Room temperature ADC voltage
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float VADCH; // Hot temperature ADC voltage
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} nvm_calibration_data_t;
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// Decimal to fraction conversion. (adapted from ASF sample).
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STATIC float convert_dec_to_frac(uint8_t val) {
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float float_val = (float)val;
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if (val < 10) {
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return (float_val/10.0);
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} else if (val < 100) {
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return (float_val/100.0);
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} else {
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return (float_val/1000.0);
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}
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}
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STATIC void configure_adc_temp(struct adc_module *adc_instance) {
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struct adc_config config_adc;
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adc_get_config_defaults(&config_adc);
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// The parameters chosen here are from the temperature example in:
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// http://www.atmel.com/images/Atmel-42645-ADC-Configurations-with-Examples_ApplicationNote_AT11481.pdf
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// That note also recommends in general:
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// "Discard the first conversion result whenever there is a change
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// in ADC configuration like voltage reference / ADC channel change."
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config_adc.clock_prescaler = ADC_CLOCK_PRESCALER_DIV16;
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config_adc.reference = ADC_REFERENCE_INT1V;
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config_adc.positive_input = ADC_POSITIVE_INPUT_TEMP;
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config_adc.negative_input = ADC_NEGATIVE_INPUT_GND;
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config_adc.sample_length = ADC_TEMP_SAMPLE_LENGTH;
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adc_init(adc_instance, ADC, &config_adc);
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// Oversample and decimate. A higher samplenum produces a more stable result.
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ADC->AVGCTRL.reg = ADC_AVGCTRL_ADJRES(2) | ADC_AVGCTRL_SAMPLENUM_4;
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//ADC->AVGCTRL.reg = ADC_AVGCTRL_ADJRES(4) | ADC_AVGCTRL_SAMPLENUM_16;
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}
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// Extract the production calibration data information from NVM (adapted from ASF sample).
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//
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STATIC void load_calibration_data(nvm_calibration_data_t *cal) {
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volatile uint32_t val1; /* Temperature Log Row Content first 32 bits */
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volatile uint32_t val2; /* Temperature Log Row Content another 32 bits */
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uint8_t room_temp_val_int; /* Integer part of room temperature in °C */
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uint8_t room_temp_val_dec; /* Decimal part of room temperature in °C */
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uint8_t hot_temp_val_int; /* Integer part of hot temperature in °C */
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uint8_t hot_temp_val_dec; /* Decimal part of hot temperature in °C */
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int8_t room_int1v_val; /* internal 1V reference drift at room temperature */
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int8_t hot_int1v_val; /* internal 1V reference drift at hot temperature*/
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uint32_t *temp_log_row_ptr = (uint32_t *)NVMCTRL_TEMP_LOG;
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val1 = *temp_log_row_ptr;
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temp_log_row_ptr++;
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val2 = *temp_log_row_ptr;
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room_temp_val_int = (uint8_t)((val1 & NVMCTRL_FUSES_ROOM_TEMP_VAL_INT_Msk) >> NVMCTRL_FUSES_ROOM_TEMP_VAL_INT_Pos);
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room_temp_val_dec = (uint8_t)((val1 & NVMCTRL_FUSES_ROOM_TEMP_VAL_DEC_Msk) >> NVMCTRL_FUSES_ROOM_TEMP_VAL_DEC_Pos);
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hot_temp_val_int = (uint8_t)((val1 & NVMCTRL_FUSES_HOT_TEMP_VAL_INT_Msk) >> NVMCTRL_FUSES_HOT_TEMP_VAL_INT_Pos);
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hot_temp_val_dec = (uint8_t)((val1 & NVMCTRL_FUSES_HOT_TEMP_VAL_DEC_Msk) >> NVMCTRL_FUSES_HOT_TEMP_VAL_DEC_Pos);
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room_int1v_val = (int8_t)((val1 & NVMCTRL_FUSES_ROOM_INT1V_VAL_Msk) >> NVMCTRL_FUSES_ROOM_INT1V_VAL_Pos);
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hot_int1v_val = (int8_t)((val2 & NVMCTRL_FUSES_HOT_INT1V_VAL_Msk) >> NVMCTRL_FUSES_HOT_INT1V_VAL_Pos);
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cal->ADCR = (uint16_t)((val2 & NVMCTRL_FUSES_ROOM_ADC_VAL_Msk) >> NVMCTRL_FUSES_ROOM_ADC_VAL_Pos);
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cal->ADCH = (uint16_t)((val2 & NVMCTRL_FUSES_HOT_ADC_VAL_Msk) >> NVMCTRL_FUSES_HOT_ADC_VAL_Pos);
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cal->tempR = room_temp_val_int + convert_dec_to_frac(room_temp_val_dec);
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cal->tempH = hot_temp_val_int + convert_dec_to_frac(hot_temp_val_dec);
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cal->INT1VR = 1 - ((float)room_int1v_val/INT1V_DIVIDER_1000);
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cal->INT1VH = 1 - ((float)hot_int1v_val/INT1V_DIVIDER_1000);
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cal->VADCR = ((float)cal->ADCR * cal->INT1VR)/ADC_12BIT_FULL_SCALE_VALUE_FLOAT;
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cal->VADCH = ((float)cal->ADCH * cal->INT1VH)/ADC_12BIT_FULL_SCALE_VALUE_FLOAT;
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}
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/*
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* Calculate fine temperature using Equation1 and Equation
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* 1b as mentioned in data sheet section "Temperature Sensor Characteristics"
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* of Electrical Characteristics. (adapted from ASF sample code).
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*/
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STATIC float calculate_temperature(uint16_t raw_code, nvm_calibration_data_t *cal)
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{
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float VADC; /* Voltage calculation using ADC result for Coarse Temp calculation */
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float VADCM; /* Voltage calculation using ADC result for Fine Temp calculation. */
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float INT1VM; /* Voltage calculation for reality INT1V value during the ADC conversion */
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VADC = ((float)raw_code * INT1V_VALUE_FLOAT)/ADC_12BIT_FULL_SCALE_VALUE_FLOAT;
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// Hopefully compiler will remove common subepxressions here.
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/* Coarse Temp Calculation by assume INT1V=1V for this ADC conversion */
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float coarse_temp = cal->tempR + (((cal->tempH - cal->tempR)/(cal->VADCH - cal->VADCR)) * (VADC - cal->VADCR));
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/* Calculation to find the real INT1V value during the ADC conversion */
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INT1VM = cal->INT1VR + (((cal->INT1VH - cal->INT1VR) * (coarse_temp - cal->tempR))/(cal->tempH - cal->tempR));
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VADCM = ((float)raw_code * INT1VM)/ADC_12BIT_FULL_SCALE_VALUE_FLOAT;
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/* Fine Temp Calculation by replace INT1V=1V by INT1V = INT1Vm for ADC conversion */
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float fine_temp = cal->tempR + (((cal->tempH - cal->tempR)/(cal->VADCH - cal->VADCR)) * (VADCM - cal->VADCR));
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return fine_temp;
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}
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// External interface.
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//
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float common_hal_mcu_processor_get_temperature(void) {
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struct adc_module adc_instance_struct;
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system_voltage_reference_enable(SYSTEM_VOLTAGE_REFERENCE_TEMPSENSE);
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configure_adc_temp(&adc_instance_struct);
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nvm_calibration_data_t nvm_calibration_data;
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load_calibration_data(&nvm_calibration_data);
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adc_enable(&adc_instance_struct);
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uint16_t data;
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enum status_code status;
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// Read twice and discard first result, as recommended in section 14 of
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// http://www.atmel.com/images/Atmel-42645-ADC-Configurations-with-Examples_ApplicationNote_AT11481.pdf
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// "Discard the first conversion result whenever there is a change in ADC configuration
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// like voltage reference / ADC channel change"
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// Empirical observation shows the first reading is quite different than subsequent ones.
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adc_start_conversion(&adc_instance_struct);
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do {
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status = adc_read(&adc_instance_struct, &data);
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} while (status == STATUS_BUSY);
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adc_start_conversion(&adc_instance_struct);
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do {
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status = adc_read(&adc_instance_struct, &data);
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} while (status == STATUS_BUSY);
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return calculate_temperature(data, &nvm_calibration_data);
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}
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uint32_t common_hal_mcu_processor_get_frequency(void) {
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return system_cpu_clock_get_hz();
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}
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