/* * This file is part of the MicroPython project, http://micropython.org/ * * The MIT License (MIT) * * Copyright (c) 2017 Dan Halbert for Adafruit Industries * * 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. */ /* * Includes code from ASF sample code adc_temp.h and adc_temp.c, * and so includes this license: * * Copyright (C) 2015 Atmel Corporation. All rights reserved. * * License * * 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. The name of Atmel may not be used to endorse or promote products derived * from this software without specific prior written permission. * * 4. This software may only be redistributed and used in connection with an * Atmel microcontroller product. * * THIS SOFTWARE IS PROVIDED BY ATMEL "AS IS" AND ANY EXPRESS OR IMPLIED * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT ARE * EXPRESSLY AND SPECIFICALLY DISCLAIMED. IN NO EVENT SHALL ATMEL 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. */ #include "common-hal/microcontroller/Processor.h" // Don't reorder these includes because they are dependencies of adc_feature.h. // They should really be included by adc_feature.h. #include #include "asf/sam0/drivers/system/clock/gclk.h" #include "asf/sam0/utils/cmsis/samd21/include/component/adc.h" #include "asf/sam0/drivers/adc/adc_sam_d_r/adc_feature.h" #include "asf/sam0/drivers/adc/adc.h" #define ADC_TEMP_SAMPLE_LENGTH 4 #define INT1V_VALUE_FLOAT 1.0 #define INT1V_DIVIDER_1000 1000.0 #define ADC_12BIT_FULL_SCALE_VALUE_FLOAT 4095.0 typedef struct nvm_calibration_data_t { float tempR; // Production Room temperature float tempH; // Production Hot temperature float INT1VR; // Room temp 2's complement of the internal 1V reference value float INT1VH; // Hot temp 2's complement of the internal 1V reference value uint16_t ADCR; // Production Room temperature ADC value uint16_t ADCH; // Production Hot temperature ADC value float VADCR; // Room temperature ADC voltage float VADCH; // Hot temperature ADC voltage } nvm_calibration_data_t; // Decimal to fraction conversion. (adapted from ASF sample). STATIC float convert_dec_to_frac(uint8_t val) { float float_val = (float)val; if (val < 10) { return (float_val/10.0); } else if (val < 100) { return (float_val/100.0); } else { return (float_val/1000.0); } } STATIC void configure_adc_temp(struct adc_module *adc_instance) { struct adc_config config_adc; adc_get_config_defaults(&config_adc); // The parameters chosen here are from the temperature example in: // http://www.atmel.com/images/Atmel-42645-ADC-Configurations-with-Examples_ApplicationNote_AT11481.pdf // That note also recommends in general: // "Discard the first conversion result whenever there is a change // in ADC configuration like voltage reference / ADC channel change." // Default input clock is GCLK0 (48 MHz) // 48Mhz / 32 = 1.5MHz. Max ADC clock is 2.1MHz config_adc.clock_prescaler = ADC_CLOCK_PRESCALER_DIV32; config_adc.reference = ADC_REFERENCE_INT1V; config_adc.positive_input = ADC_POSITIVE_INPUT_TEMP; config_adc.negative_input = ADC_NEGATIVE_INPUT_GND; config_adc.sample_length = ADC_TEMP_SAMPLE_LENGTH; adc_init(adc_instance, ADC, &config_adc); // Oversample and decimate. A higher samplenum produces a more stable result. ADC->AVGCTRL.reg = ADC_AVGCTRL_ADJRES(2) | ADC_AVGCTRL_SAMPLENUM_4; //ADC->AVGCTRL.reg = ADC_AVGCTRL_ADJRES(4) | ADC_AVGCTRL_SAMPLENUM_16; } // Extract the production calibration data information from NVM (adapted from ASF sample). // STATIC void load_calibration_data(nvm_calibration_data_t *cal) { volatile uint32_t val1; /* Temperature Log Row Content first 32 bits */ volatile uint32_t val2; /* Temperature Log Row Content another 32 bits */ uint8_t room_temp_val_int; /* Integer part of room temperature in °C */ uint8_t room_temp_val_dec; /* Decimal part of room temperature in °C */ uint8_t hot_temp_val_int; /* Integer part of hot temperature in °C */ uint8_t hot_temp_val_dec; /* Decimal part of hot temperature in °C */ int8_t room_int1v_val; /* internal 1V reference drift at room temperature */ int8_t hot_int1v_val; /* internal 1V reference drift at hot temperature*/ uint32_t *temp_log_row_ptr = (uint32_t *)NVMCTRL_TEMP_LOG; val1 = *temp_log_row_ptr; temp_log_row_ptr++; val2 = *temp_log_row_ptr; room_temp_val_int = (uint8_t)((val1 & NVMCTRL_FUSES_ROOM_TEMP_VAL_INT_Msk) >> NVMCTRL_FUSES_ROOM_TEMP_VAL_INT_Pos); room_temp_val_dec = (uint8_t)((val1 & NVMCTRL_FUSES_ROOM_TEMP_VAL_DEC_Msk) >> NVMCTRL_FUSES_ROOM_TEMP_VAL_DEC_Pos); hot_temp_val_int = (uint8_t)((val1 & NVMCTRL_FUSES_HOT_TEMP_VAL_INT_Msk) >> NVMCTRL_FUSES_HOT_TEMP_VAL_INT_Pos); hot_temp_val_dec = (uint8_t)((val1 & NVMCTRL_FUSES_HOT_TEMP_VAL_DEC_Msk) >> NVMCTRL_FUSES_HOT_TEMP_VAL_DEC_Pos); room_int1v_val = (int8_t)((val1 & NVMCTRL_FUSES_ROOM_INT1V_VAL_Msk) >> NVMCTRL_FUSES_ROOM_INT1V_VAL_Pos); hot_int1v_val = (int8_t)((val2 & NVMCTRL_FUSES_HOT_INT1V_VAL_Msk) >> NVMCTRL_FUSES_HOT_INT1V_VAL_Pos); cal->ADCR = (uint16_t)((val2 & NVMCTRL_FUSES_ROOM_ADC_VAL_Msk) >> NVMCTRL_FUSES_ROOM_ADC_VAL_Pos); cal->ADCH = (uint16_t)((val2 & NVMCTRL_FUSES_HOT_ADC_VAL_Msk) >> NVMCTRL_FUSES_HOT_ADC_VAL_Pos); cal->tempR = room_temp_val_int + convert_dec_to_frac(room_temp_val_dec); cal->tempH = hot_temp_val_int + convert_dec_to_frac(hot_temp_val_dec); cal->INT1VR = 1 - ((float)room_int1v_val/INT1V_DIVIDER_1000); cal->INT1VH = 1 - ((float)hot_int1v_val/INT1V_DIVIDER_1000); cal->VADCR = ((float)cal->ADCR * cal->INT1VR)/ADC_12BIT_FULL_SCALE_VALUE_FLOAT; cal->VADCH = ((float)cal->ADCH * cal->INT1VH)/ADC_12BIT_FULL_SCALE_VALUE_FLOAT; } /* * Calculate fine temperature using Equation1 and Equation * 1b as mentioned in data sheet section "Temperature Sensor Characteristics" * of Electrical Characteristics. (adapted from ASF sample code). */ STATIC float calculate_temperature(uint16_t raw_code, nvm_calibration_data_t *cal) { float VADC; /* Voltage calculation using ADC result for Coarse Temp calculation */ float VADCM; /* Voltage calculation using ADC result for Fine Temp calculation. */ float INT1VM; /* Voltage calculation for reality INT1V value during the ADC conversion */ VADC = ((float)raw_code * INT1V_VALUE_FLOAT)/ADC_12BIT_FULL_SCALE_VALUE_FLOAT; // Hopefully compiler will remove common subepxressions here. /* Coarse Temp Calculation by assume INT1V=1V for this ADC conversion */ float coarse_temp = cal->tempR + (((cal->tempH - cal->tempR)/(cal->VADCH - cal->VADCR)) * (VADC - cal->VADCR)); /* Calculation to find the real INT1V value during the ADC conversion */ INT1VM = cal->INT1VR + (((cal->INT1VH - cal->INT1VR) * (coarse_temp - cal->tempR))/(cal->tempH - cal->tempR)); VADCM = ((float)raw_code * INT1VM)/ADC_12BIT_FULL_SCALE_VALUE_FLOAT; /* Fine Temp Calculation by replace INT1V=1V by INT1V = INT1Vm for ADC conversion */ float fine_temp = cal->tempR + (((cal->tempH - cal->tempR)/(cal->VADCH - cal->VADCR)) * (VADCM - cal->VADCR)); return fine_temp; } // External interface. // float common_hal_mcu_processor_get_temperature(void) { struct adc_module adc_instance_struct; system_voltage_reference_enable(SYSTEM_VOLTAGE_REFERENCE_TEMPSENSE); configure_adc_temp(&adc_instance_struct); nvm_calibration_data_t nvm_calibration_data; load_calibration_data(&nvm_calibration_data); adc_enable(&adc_instance_struct); uint16_t data; enum status_code status; // Read twice and discard first result, as recommended in section 14 of // http://www.atmel.com/images/Atmel-42645-ADC-Configurations-with-Examples_ApplicationNote_AT11481.pdf // "Discard the first conversion result whenever there is a change in ADC configuration // like voltage reference / ADC channel change" // Empirical observation shows the first reading is quite different than subsequent ones. adc_start_conversion(&adc_instance_struct); do { status = adc_read(&adc_instance_struct, &data); } while (status == STATUS_BUSY); adc_start_conversion(&adc_instance_struct); do { status = adc_read(&adc_instance_struct, &data); } while (status == STATUS_BUSY); // Disable so that someone else can use the adc with different settings. adc_disable(&adc_instance_struct); return calculate_temperature(data, &nvm_calibration_data); } uint32_t common_hal_mcu_processor_get_frequency(void) { return system_cpu_clock_get_hz(); }