/* Reflow Oven Controller * * Copyright (C) 2020 Mario Hüttel * * This file is part of the Reflow Oven Controller Project. * * The reflow oven controller is free software: you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. * * GDSII-Converter is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with the reflow oven controller project. * If not, see . */ /** * @file adc-meas.h */ #ifndef __ADCMEAS_H__ #define __ADCMEAS_H__ #include #include #include /*If this is changed, change DMA code to fit the channel assignment! */ #define ADC_PT1000_PERIPH ADC3 #define ADC_PT1000_DMA2_STREAM0_CHANNEL 2 /** * @brief Moving average filter coefficient for PT1000 measurement */ #define ADC_PT1000_FILTER_WEIGHT 0.01f /** * @brief Moving average filter weight used for fast regaulation. This is used when the measured resistance * is more than @ref ADC_PT1000_FILTER_UNSTABLE_DIFF Ohms away from the current averaged value. */ #define ADC_PT1000_FILTER_WEIGHT_FAST 0.05 /** * @brief Difference in Ohm between filter input and output that determines if the filter is stable or unstable. */ #define ADC_PT1000_FILTER_UNSTABLE_DIFF 20 /** * @brief Sample count, the moving average filter has to be within @ref ADC_PT1000_FILTER_UNSTABLE_DIFF for the filter * to be considered stable */ #define ADC_PT1000_FILTER_STABLE_SAMPLE_COUNT 200 /** * @brief ADC channel number of PT1000 sensor input */ #define ADC_PT1000_CHANNEL 2U /** * @brief GPIO Port the ADC converter for the PT1000 measurement is connected to */ #define ADC_PT1000_PORT GPIOA /** * @brief The clock enable mask of the RCC register for ADC_PT1000_PORT */ #define ADC_PT1000_PORT_RCC_MASK RCC_AHB1ENR_GPIOAEN /** * @brief The GPIO pin number the PT1000 analog voltage is connected to */ #define ADC_PT1000_PIN 2U /** * @brief The delay value programmed into the sample timer */ #define ADC_PT1000_SAMPLE_CNT_DELAY 1000U /** * @brief The amount of samples to take to prefilter the analog signal */ #define ADC_PT1000_DMA_AVG_SAMPLES 6U /** * @brief Lower value for valid input range for PT1000 measurement * * If the input of the PT1000 sensor is below this value, an error is thrown. This is used to disable the temperature control loop */ #define ADC_PT1000_LOWER_WATCHDOG 200U /** * @brief Upper value for valid input range for PT1000 measurement * * If the input of the PT1000 sensor is above this value, an error is thrown. This is used to disable the temperature control loop */ #define ADC_PT1000_UPPER_WATCHDOG 4000U /** * @brief Number of ADC samples the value has to be outside the Watchdog limit (@ref ADC_PT1000_UPPER_WATCHDOG and @ref ADC_PT1000_LOWER_WATCHDOG) * in order to produce a watchdog error */ #define ADC_PT1000_WATCHDOG_SAMPLE_COUNT 25U /** * @brief Conversion macro: ADC value to resistance */ #define ADC_TO_RES(adc) ((float)(adc) / 4096.0f * 2500.0f) #define RES_TO_ADC(res) ((float)(res) / 2500.0f * 4096.0f) /** * @brief This function sets up the ADC measurement fo the external PT1000 temperature sensor * * Used peripherals: * - Timer 2 for sampling control * - ADC1 * * The filter weight \f$\alpha\f$ is configured for @ref ADC_PT1000_FILTER_WEIGHT * */ void adc_pt1000_setup_meas(void); /** * @brief Set moving average filter parameters * * The sampled resistance value is filtered with an exponential average filter * specified by following difference equation: * * \f$ y[n] = (1-\alpha)y[n-1] + \alpha x[n] \f$ * * @param alpha */ void adc_pt1000_set_moving_average_filter_param(float alpha); /** * @brief Set the calibration data for the PT1000 measurement * * The resulting resistance reading is * \f$R_{corrected} = (1 + \sigma) R_{raw} + O\f$ * * @param offset Offset \f$O\f$ * @param sensitivity_deviation Sensitivity Deviation \f$\sigma\f$ after offset correction * @param active Calibration is active */ void adc_pt1000_set_resistance_calibration(float offset, float sensitivity_deviation, bool active); /** * @brief Get the state and values of the resistance calibration * @param offset Offset * @param sensitivity_deviation Sensitivity deviation * @param active Active state of the correction */ void adc_pt1000_get_resistance_calibration(float *offset, float *sensitivity_deviation, bool *active); /** * @brief Get the current resistance value * * If the resistance calibration is enabled, this function applies the calculations of the raw resistance reading and * returns the corrected value. * * If an ADC error is set, the status is negative. The status is 2 during the first measurements with a given filter setting. Technically, the resistance value is * correct but the filter is not stable yet. * * @param[out] resistance Resistance output in Ohms * @return Status */ int adc_pt1000_get_current_resistance(float *resistance); /** * @brief Stream the raw ADC data to an array in memory. * @param adc_array Array to stream data to * @param length Amount of data points to be measured * @param flag_to_set This flag is set to 1 once the data has been measured and is transferred. A negative value indicates an error * @return 0 if measurement could be started */ int adc_pt1000_stream_raw_value_to_memory(volatile float *adc_array, uint32_t length, volatile int *flag_to_set); /** * @brief Convert an array of raw adc values to resistance values * * In case \p resistance_dest is NULL, the conversion is done inplace in the * \p raw_source array. * * @param resistance_dest Destination. Maybe NULL. * @param raw_source Source array * @param count Number of values to convert */ void adc_pt1000_convert_raw_value_array_to_resistance(float *resistance_dest, float *raw_source, uint32_t count); /** * @brief Disable the PT1000 measurement */ void adc_pt1000_disable(void); #endif // __ADCMEAS_H__