/** @addtogroup adc_file ADC peripheral API @ingroup peripheral_apis @author @htmlonly © @endhtmlonly 2009 Edward Cheeseman @author @htmlonly © @endhtmlonly 2012 Ken Sarkies @author @htmlonly © @endhtmlonly 2014 Karl Palsson This library supports one style of the Analog to Digital Conversion System in the STM32 series of ARM Cortex Microcontrollers by ST Microelectronics. The style of ADC Peripheral supported by this code is found in the F1, F2, F37x, F38x, F4, and L1 series devices (at the time of writing) but is quite different to the style found on the F0 and F30x and F31x. Devices can have up to three A/D converters each with their own set of registers. However all the A/D converters share a common clock. On most devices, this is prescaled from the APB2 clock by default by a minimum factor of 2 to a maximum of 8, though on the L1 this is always a divider from the HSI. (And therefore HSI _must_ be enabled before attempting to enable the ADC) Each A/D converter has up to ADC_MAX_CHANNELS channels: @li On ADC1 the analog channels 16 and 17 are internally connected to the temperature sensor and VREFINT, respectively. @li On ADC2 (if available) the analog channels 16 and 17 are internally connected to VSS. @li On ADC3 (if available) the analog channels 9, 14, 15, 16 and 17 are internally connected to VSS. The conversions can occur as a one-off conversion whereby the process stops once conversion is complete. The conversions can also be continuous wherein a new conversion starts immediately the previous conversion has ended. Conversion can occur as a single channel conversion or a scan of a group of channels in either continuous or one-off mode. If more than one channel is converted in a scan group, DMA must be used to transfer the data as there is only one result register available. An interrupt can be set to occur at the end of conversion, which occurs after all channels have been scanned. A discontinuous mode allows a subgroup of group of a channels to be converted in bursts of a given length. Injected conversions allow a second group of channels to be converted separately from the regular group. An interrupt can be set to occur at the end of conversion, which occurs after all channels have been scanned. @section adc_api_ex Basic ADC Handling API. Example 1: Simple single channel conversion polled. Enable the peripheral clock and ADC, reset ADC and set the prescaler divider. Set dual mode to independent (default). Enable triggering for a software trigger. @code rcc_periph_clock_enable(RCC_ADC1); adc_power_off(ADC1); rcc_periph_reset_pulse(RST_ADC1); rcc_set_adcpre(RCC_CFGR_ADCPRE_PCLK2_DIV2); adc_set_dual_mode(ADC_CR1_DUALMOD_IND); adc_disable_scan_mode(ADC1); adc_set_single_conversion_mode(ADC1); adc_set_sample_time(ADC1, ADC_CHANNEL0, ADC_SMPR1_SMP_1DOT5CYC); adc_enable_trigger(ADC1, ADC_CR2_EXTSEL_SWSTART); adc_power_on(ADC1); adc_reset_calibration(ADC1); adc_calibration(ADC1); adc_start_conversion_regular(ADC1); while (! adc_eoc(ADC1)); reg16 = adc_read_regular(ADC1); @endcode LGPL License Terms @ref lgpl_license */ /* * This file is part of the libopencm3 project. * * Copyright (C) 2014 Karl Palsson * * This library is free software: you can redistribute it and/or modify * it under the terms of the GNU Lesser General Public License as published by * the Free Software Foundation, either version 3 of the License, or * (at your option) any later version. * * This library 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 Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public License * along with this library. If not, see . */ /**@{*/ #include /*---------------------------------------------------------------------------*/ /** @brief ADC Off Turn off the ADC to reduce power consumption to a few microamps. @param[in] adc Unsigned int32. ADC block register address base @ref adc_reg_base. */ void adc_power_off(uint32_t adc) { ADC_CR2(adc) &= ~ADC_CR2_ADON; } /*---------------------------------------------------------------------------*/ /** @brief ADC Enable Analog Watchdog for Regular Conversions The analog watchdog allows the monitoring of an analog signal between two threshold levels. The thresholds must be preset. @param[in] adc Unsigned int32. ADC block register address base @ref adc_reg_base. */ void adc_enable_analog_watchdog_regular(uint32_t adc) { ADC_CR1(adc) |= ADC_CR1_AWDEN; } /*---------------------------------------------------------------------------*/ /** @brief ADC Disable Analog Watchdog for Regular Conversions @param[in] adc Unsigned int32. ADC block register address base @ref adc_reg_base. */ void adc_disable_analog_watchdog_regular(uint32_t adc) { ADC_CR1(adc) &= ~ADC_CR1_AWDEN; } /*---------------------------------------------------------------------------*/ /** @brief ADC Enable Analog Watchdog for Injected Conversions The analog watchdog allows the monitoring of an analog signal between two threshold levels. The thresholds must be preset. Comparison is done before data alignment takes place, so the thresholds are left-aligned. @param[in] adc Unsigned int32. ADC block register address base @ref adc_reg_base */ void adc_enable_analog_watchdog_injected(uint32_t adc) { ADC_CR1(adc) |= ADC_CR1_JAWDEN; } /*---------------------------------------------------------------------------*/ /** @brief ADC Disable Analog Watchdog for Injected Conversions @param[in] adc Unsigned int32. ADC block register address base @ref adc_reg_base */ void adc_disable_analog_watchdog_injected(uint32_t adc) { ADC_CR1(adc) &= ~ADC_CR1_JAWDEN; } /*---------------------------------------------------------------------------*/ /** @brief ADC Enable Discontinuous Mode for Regular Conversions In this mode the ADC converts, on each trigger, a subgroup of up to 8 of the defined regular channel group. The subgroup is defined by the number of consecutive channels to be converted. After a subgroup has been converted the next trigger will start conversion of the immediately following subgroup of the same length or until the whole group has all been converted. When the the whole group has been converted, the next trigger will restart conversion of the subgroup at the beginning of the whole group. @param[in] adc Unsigned int32. ADC block register address base @ref adc_reg_base @param[in] length Unsigned int8. Number of channels in the group @ref adc_cr1_discnum */ void adc_enable_discontinuous_mode_regular(uint32_t adc, uint8_t length) { if ((length-1) > 7) { return; } ADC_CR1(adc) |= ADC_CR1_DISCEN; ADC_CR1(adc) |= ((length-1) << ADC_CR1_DISCNUM_SHIFT); } /*---------------------------------------------------------------------------*/ /** @brief ADC Disable Discontinuous Mode for Regular Conversions @param[in] adc Unsigned int32. ADC block register address base @ref adc_reg_base */ void adc_disable_discontinuous_mode_regular(uint32_t adc) { ADC_CR1(adc) &= ~ADC_CR1_DISCEN; } /*---------------------------------------------------------------------------*/ /** @brief ADC Enable Discontinuous Mode for Injected Conversions In this mode the ADC converts sequentially one channel of the defined group of injected channels, cycling back to the first channel in the group once the entire group has been converted. @param[in] adc Unsigned int32. ADC block register address base @ref adc_reg_base */ void adc_enable_discontinuous_mode_injected(uint32_t adc) { ADC_CR1(adc) |= ADC_CR1_JDISCEN; } /*---------------------------------------------------------------------------*/ /** @brief ADC Disable Discontinuous Mode for Injected Conversions @param[in] adc Unsigned int32. ADC block register address base @ref adc_reg_base */ void adc_disable_discontinuous_mode_injected(uint32_t adc) { ADC_CR1(adc) &= ~ADC_CR1_JDISCEN; } /*---------------------------------------------------------------------------*/ /** @brief ADC Enable Automatic Injected Conversions The ADC converts a defined injected group of channels immediately after the regular channels have been converted. The external trigger on the injected channels is disabled as required. @param[in] adc Unsigned int32. ADC block register address base @ref adc_reg_base */ void adc_enable_automatic_injected_group_conversion(uint32_t adc) { adc_disable_external_trigger_injected(adc); ADC_CR1(adc) |= ADC_CR1_JAUTO; } /*---------------------------------------------------------------------------*/ /** @brief ADC Disable Automatic Injected Conversions @param[in] adc Unsigned int32. ADC block register address base @ref adc_reg_base */ void adc_disable_automatic_injected_group_conversion(uint32_t adc) { ADC_CR1(adc) &= ~ADC_CR1_JAUTO; } /*---------------------------------------------------------------------------*/ /** @brief ADC Enable Analog Watchdog for All Regular and/or Injected Channels The analog watchdog allows the monitoring of an analog signal between two threshold levels. The thresholds must be preset. Comparison is done before data alignment takes place, so the thresholds are left-aligned. @note The analog watchdog must be enabled for either or both of the regular or injected channels. If neither are enabled, the analog watchdog feature will be disabled. @ref adc_enable_analog_watchdog_injected, @ref adc_enable_analog_watchdog_regular. @param[in] adc Unsigned int32. ADC block register address base @ref adc_reg_base */ void adc_enable_analog_watchdog_on_all_channels(uint32_t adc) { ADC_CR1(adc) &= ~ADC_CR1_AWDSGL; } /*---------------------------------------------------------------------------*/ /** @brief ADC Enable Analog Watchdog for a Selected Channel The analog watchdog allows the monitoring of an analog signal between two threshold levels. The thresholds must be preset. Comparison is done before data alignment takes place, so the thresholds are left-aligned. @note The analog watchdog must be enabled for either or both of the regular or injected channels. If neither are enabled, the analog watchdog feature will be disabled. If both are enabled, the same channel number is monitored. @ref adc_enable_analog_watchdog_injected, @ref adc_enable_analog_watchdog_regular. @param[in] adc Unsigned int32. ADC block register address base @ref adc_reg_base @param[in] channel Unsigned int8. ADC channel number @ref adc_watchdog_channel */ void adc_enable_analog_watchdog_on_selected_channel(uint32_t adc, uint8_t channel) { uint32_t reg32; reg32 = (ADC_CR1(adc) & ~ADC_CR1_AWDCH_MASK); /* Clear bits [4:0]. */ if (channel <= ADC_CR1_AWDCH_MAX) { reg32 |= channel; } ADC_CR1(adc) = reg32; ADC_CR1(adc) |= ADC_CR1_AWDSGL; } /*---------------------------------------------------------------------------*/ /** @brief ADC Set Scan Mode In this mode a conversion consists of a scan of the predefined set of channels, regular and injected, each channel conversion immediately following the previous one. It can use single, continuous or discontinuous mode. @param[in] adc Unsigned int32. ADC block register address base @ref adc_reg_base */ void adc_enable_scan_mode(uint32_t adc) { ADC_CR1(adc) |= ADC_CR1_SCAN; } /*---------------------------------------------------------------------------*/ /** @brief ADC Disable Scan Mode @param[in] adc Unsigned int32. ADC block register address base @ref adc_reg_base */ void adc_disable_scan_mode(uint32_t adc) { ADC_CR1(adc) &= ~ADC_CR1_SCAN; } /*---------------------------------------------------------------------------*/ /** @brief ADC Enable Injected End-Of-Conversion Interrupt @param[in] adc Unsigned int32. ADC block register address base @ref adc_reg_base */ void adc_enable_eoc_interrupt_injected(uint32_t adc) { ADC_CR1(adc) |= ADC_CR1_JEOCIE; } /*---------------------------------------------------------------------------*/ /** @brief ADC Disable Injected End-Of-Conversion Interrupt @param[in] adc Unsigned int32. ADC block register address base @ref adc_reg_base */ void adc_disable_eoc_interrupt_injected(uint32_t adc) { ADC_CR1(adc) &= ~ADC_CR1_JEOCIE; } /*---------------------------------------------------------------------------*/ /** @brief ADC Enable Analog Watchdog Interrupt @param[in] adc Unsigned int32. ADC block register address base @ref adc_reg_base */ void adc_enable_awd_interrupt(uint32_t adc) { ADC_CR1(adc) |= ADC_CR1_AWDIE; } /*---------------------------------------------------------------------------*/ /** @brief ADC Disable Analog Watchdog Interrupt @param[in] adc Unsigned int32. ADC block register address base @ref adc_reg_base */ void adc_disable_awd_interrupt(uint32_t adc) { ADC_CR1(adc) &= ~ADC_CR1_AWDIE; } /*---------------------------------------------------------------------------*/ /** @brief ADC Enable Regular End-Of-Conversion Interrupt @param[in] adc Unsigned int32. ADC block register address base @ref adc_reg_base */ void adc_enable_eoc_interrupt(uint32_t adc) { ADC_CR1(adc) |= ADC_CR1_EOCIE; } /*---------------------------------------------------------------------------*/ /** @brief ADC Disable Regular End-Of-Conversion Interrupt @param[in] adc Unsigned int32. ADC block register address base @ref adc_reg_base */ void adc_disable_eoc_interrupt(uint32_t adc) { ADC_CR1(adc) &= ~ADC_CR1_EOCIE; } /*---------------------------------------------------------------------------*/ /** @brief ADC Set the Data as Left Aligned @param[in] adc Unsigned int32. ADC block register address base @ref adc_reg_base. */ void adc_set_left_aligned(uint32_t adc) { ADC_CR2(adc) |= ADC_CR2_ALIGN; } /*---------------------------------------------------------------------------*/ /** @brief ADC Set the Data as Right Aligned @param[in] adc Unsigned int32. ADC block register address base @ref adc_reg_base. */ void adc_set_right_aligned(uint32_t adc) { ADC_CR2(adc) &= ~ADC_CR2_ALIGN; } /*---------------------------------------------------------------------------*/ /** @brief ADC Read the End-of-Conversion Flag This flag is set after all channels of a regular or injected group have been converted. @param[in] adc Unsigned int32. ADC block register address base @ref adc_reg_base @returns bool. End of conversion flag. */ bool adc_eoc(uint32_t adc) { return (ADC_SR(adc) & ADC_SR_EOC) != 0; } /*---------------------------------------------------------------------------*/ /** @brief ADC Read the End-of-Conversion Flag for Injected Conversion This flag is set after all channels of an injected group have been converted. @param[in] adc Unsigned int32. ADC block register address base @ref adc_reg_base @returns bool. End of conversion flag. */ bool adc_eoc_injected(uint32_t adc) { return (ADC_SR(adc) & ADC_SR_JEOC) != 0; } /*---------------------------------------------------------------------------*/ /** @brief ADC Read from the Regular Conversion Result Register The result read back is 12 bits, right or left aligned within the first 16 bits. For ADC1 only, the higher 16 bits will hold the result from ADC2 if an appropriate dual mode has been set @see adc_set_dual_mode. @param[in] adc Unsigned int32. ADC block register address base @ref adc_reg_base @returns Unsigned int32 conversion result. */ uint32_t adc_read_regular(uint32_t adc) { return ADC_DR(adc); } /*---------------------------------------------------------------------------*/ /** @brief ADC Read from an Injected Conversion Result Register The result read back from the selected injected result register (one of four) is 12 bits, right or left aligned within the first 16 bits. The result can have a negative value if the injected channel offset has been set @see adc_set_injected_offset. @param[in] adc Unsigned int32. ADC block register address base @ref adc_reg_base @param[in] reg Unsigned int8. Register number (1 ... 4). @returns Unsigned int32 conversion result. */ uint32_t adc_read_injected(uint32_t adc, uint8_t reg) { switch (reg) { case 1: return ADC_JDR1(adc); case 2: return ADC_JDR2(adc); case 3: return ADC_JDR3(adc); case 4: return ADC_JDR4(adc); } return 0; } /*---------------------------------------------------------------------------*/ /** @brief ADC Enable Continuous Conversion Mode In this mode the ADC starts a new conversion of a single channel or a channel group immediately following completion of the previous channel group conversion. @param[in] adc Unsigned int32. ADC block register address base @ref adc_reg_base */ void adc_set_continuous_conversion_mode(uint32_t adc) { ADC_CR2(adc) |= ADC_CR2_CONT; } /*---------------------------------------------------------------------------*/ /** @brief ADC Enable Single Conversion Mode In this mode the ADC performs a conversion of one channel or a channel group and stops. @param[in] adc Unsigned int32. ADC block register address base @ref adc_reg_base. */ void adc_set_single_conversion_mode(uint32_t adc) { ADC_CR2(adc) &= ~ADC_CR2_CONT; } /*---------------------------------------------------------------------------*/ /** @brief ADC Set Analog Watchdog Upper Threshold @param[in] adc Unsigned int32. ADC block register address base @ref adc_reg_base @param[in] threshold Upper threshold value, 12bit right aligned. */ void adc_set_watchdog_high_threshold(uint32_t adc, uint16_t threshold) { uint32_t reg32 = 0; reg32 = (uint32_t)threshold; reg32 &= ADC_HT_MSK; ADC_HTR(adc) = reg32; } /*---------------------------------------------------------------------------*/ /** @brief ADC Set Analog Watchdog Lower Threshold @param[in] adc Unsigned int32. ADC block register address base @ref adc_reg_base @param[in] threshold Lower threshold value, 12bit right aligned. */ void adc_set_watchdog_low_threshold(uint32_t adc, uint16_t threshold) { uint32_t reg32 = 0; reg32 = (uint32_t)threshold; reg32 &= ADC_LT_MSK; ADC_LTR(adc) = reg32; } /*---------------------------------------------------------------------------*/ /** @brief ADC Set a Regular Channel Conversion Sequence Define a sequence of channels to be converted as a regular group with a length from 1 to ADC_REGULAR_SEQUENCE_MAX channels. If this is called during conversion, the current conversion is reset and conversion begins again with the newly defined group. @param[in] adc Unsigned int32. ADC block base address @ref adc_reg_base. @param[in] length Unsigned int8. Number of channels in the group. @param[in] channel Unsigned int8[]. Set of channels in sequence, integers 0..31. */ void adc_set_regular_sequence(uint32_t adc, uint8_t length, uint8_t channel[]) { uint32_t fifth6 = 0; uint32_t fourth6 = 0; uint32_t third6 = 0; uint32_t second6 = 0; uint32_t first6 = 0; uint8_t i = 0; if (length > ADC_SQR_MAX_CHANNELS_REGULAR) { return; } for (i = 1; i <= length; i++) { if (i <= 6) { first6 |= (channel[i - 1] << ((i - 1) * 5)); } if ((i > 6) & (i <= 12)) { second6 |= (channel[i - 1] << ((i - 6 - 1) * 5)); } if ((i > 12) & (i <= 18)) { third6 |= (channel[i - 1] << ((i - 12 - 1) * 5)); } if ((i > 18) & (i <= 24)) { fourth6 |= (channel[i - 1] << ((i - 18 - 1) * 5)); } if ((i > 24) & (i <= 28)) { fifth6 |= (channel[i - 1] << ((i - 24 - 1) * 5)); } } #if defined(ADC_SQR5) ADC_SQR1(adc) = fifth6 | ((length - 1) << ADC_SQR1_L_LSB); ADC_SQR2(adc) = fourth6; ADC_SQR3(adc) = third6; ADC_SQR4(adc) = second6; ADC_SQR5(adc) = first6; #else ADC_SQR1(adc) = third6 | ((length - 1) << ADC_SQR1_L_LSB); ADC_SQR2(adc) = second6; ADC_SQR3(adc) = first6; #endif } /*---------------------------------------------------------------------------*/ /** @brief ADC Set an Injected Channel Conversion Sequence Defines a sequence of channels to be converted as an injected group with a length from 1 to 4 channels. If this is called during conversion, the current conversion is reset and conversion begins again with the newly defined group. @param[in] adc Unsigned int32. ADC block register address base @ref adc_reg_base @param[in] length Unsigned int8. Number of channels in the group. @param[in] channel Unsigned int8[]. Set of channels in sequence, integers 0..18 */ void adc_set_injected_sequence(uint32_t adc, uint8_t length, uint8_t channel[]) { uint32_t reg32 = 0; uint8_t i = 0; /* Maximum sequence length is 4 channels. Minimum sequence is 1.*/ if ((length - 1) > 3) { return; } for (i = 0; i < length; i++) { reg32 |= ADC_JSQR_JSQ_VAL(4 - i, channel[length - i - 1]); } reg32 |= ADC_JSQR_JL_VAL(length); ADC_JSQR(adc) = reg32; } /*----------------------------------------------------------------------------*/ /** @brief ADC Set the Injected Channel Data Offset This value is subtracted from the injected channel results after conversion is complete, and can result in negative results. A separate value can be specified for each injected data register. @param[in] adc Unsigned int32. ADC block register address base @ref adc_reg_base @param[in] reg Unsigned int8. Register number (1 ... 4). @param[in] offset Unsigned int32. */ void adc_set_injected_offset(uint32_t adc, uint8_t reg, uint32_t offset) { switch (reg) { case 1: ADC_JOFR1(adc) = offset; break; case 2: ADC_JOFR2(adc) = offset; break; case 3: ADC_JOFR3(adc) = offset; break; case 4: ADC_JOFR4(adc) = offset; break; } } /*---------------------------------------------------------------------------*/ /** @brief ADC Software Triggered Conversion on Regular Channels This starts conversion on a set of defined regular channels if the ADC trigger is set to be a software trigger. It is cleared by hardware once conversion starts. Special F1 Note this is a software trigger and requires triggering to be enabled and the trigger source to be set appropriately otherwise conversion will not start. This is not the same as the ADC start conversion operation. @param[in] adc Unsigned int32. ADC block register address base @ref adc_reg_base. */ void adc_start_conversion_regular(uint32_t adc) { /* Start conversion on regular channels. */ ADC_CR2(adc) |= ADC_CR2_SWSTART; /* Wait until the ADC starts the conversion. */ while (ADC_CR2(adc) & ADC_CR2_SWSTART); } /*---------------------------------------------------------------------------*/ /** @brief ADC Software Triggered Conversion on Injected Channels This starts conversion on a set of defined injected channels if the ADC trigger is set to be a software trigger. It is cleared by hardware once conversion starts. Special F1 Note this is a software trigger and requires triggering to be enabled and the trigger source to be set appropriately otherwise conversion will not start. This is not the same as the ADC start conversion operation. @param[in] adc Unsigned int32. ADC block register address base @ref adc_reg_base. */ void adc_start_conversion_injected(uint32_t adc) { /* Start conversion on injected channels. */ ADC_CR2(adc) |= ADC_CR2_JSWSTART; /* Wait until the ADC starts the conversion. */ while (ADC_CR2(adc) & ADC_CR2_JSWSTART); } /*---------------------------------------------------------------------------*/ /** @brief ADC Enable DMA Transfers @param[in] adc Unsigned int32. ADC block register address base @ref adc_reg_base */ void adc_enable_dma(uint32_t adc) { ADC_CR2(adc) |= ADC_CR2_DMA; } /*---------------------------------------------------------------------------*/ /** @brief ADC Disable DMA Transfers @param[in] adc Unsigned int32. ADC block register address base @ref adc_reg_base */ void adc_disable_dma(uint32_t adc) { ADC_CR2(adc) &= ~ADC_CR2_DMA; } /**@}*/