diff options
Diffstat (limited to 'center_fw/src/adc.c')
| -rw-r--r-- | center_fw/src/adc.c | 305 |
1 files changed, 0 insertions, 305 deletions
diff --git a/center_fw/src/adc.c b/center_fw/src/adc.c deleted file mode 100644 index 0cf70d1..0000000 --- a/center_fw/src/adc.c +++ /dev/null @@ -1,305 +0,0 @@ -/* Megumin LED display firmware - * Copyright (C) 2018 Sebastian Götte <code@jaseg.net> - * - * This program is free software: you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation, either version 3 of the License, or - * (at your option) any later version. - * - * This program 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 this program. If not, see <http://www.gnu.org/licenses/>. - */ - -#include "adc.h" - -#include <stdbool.h> -#include <stdlib.h> - -#define DETECTOR_CHANNEL a - -volatile uint16_t adc_buf[ADC_BUFSIZE]; -volatile struct adc_state adc_state = {0}; -#define st adc_state -volatile struct adc_measurements adc_data; - -static void adc_dma_init(int burstlen, bool enable_interrupt); -static void adc_timer_init(int psc, int ivl); - - -/* Mode that can be used for debugging */ -void adc_configure_scope_mode(uint8_t channel_mask, int sampling_interval_ns) { - /* The constant SAMPLE_FAST (0) when passed in as sampling_interval_ns is handled specially in that we turn the ADC - to continuous mode to get the highest possible sampling rate. */ - - /* First, disable trigger timer, DMA and ADC in case we're reconfiguring on the fly. */ - TIM1->CR1 &= ~TIM_CR1_CEN; - ADC1->CR &= ~ADC_CR_ADSTART; - DMA1_Channel1->CCR &= ~DMA_CCR_EN; - - /* keep track of current mode in global variable */ - st.adc_mode = ADC_SCOPE; - - adc_dma_init(sizeof(adc_buf)/sizeof(adc_buf[0]), true); - - /* Clock from PCLK/4 instead of the internal exclusive high-speed RC oscillator. */ - ADC1->CFGR2 = (2<<ADC_CFGR2_CKMODE_Pos); /* Use PCLK/4=12MHz */ - /* Sampling time 13.5 ADC clock cycles -> total conversion time 2.17us*/ - ADC1->SMPR = (2<<ADC_SMPR_SMP_Pos); - - /* Setup DMA and triggering */ - if (sampling_interval_ns == SAMPLE_FAST) /* Continuous trigger */ - ADC1->CFGR1 = ADC_CFGR1_DMAEN | ADC_CFGR1_DMACFG | ADC_CFGR1_CONT; - else /* Trigger from timer 1 Channel 4 */ - ADC1->CFGR1 = ADC_CFGR1_DMAEN | ADC_CFGR1_DMACFG | (2<<ADC_CFGR1_EXTEN_Pos) | (1<<ADC_CFGR1_EXTSEL_Pos); - ADC1->CHSELR = channel_mask; - /* Perform self-calibration */ - ADC1->CR |= ADC_CR_ADCAL; - while (ADC1->CR & ADC_CR_ADCAL) - ; - /* Enable conversion */ - ADC1->CR |= ADC_CR_ADEN; - ADC1->CR |= ADC_CR_ADSTART; - - if (sampling_interval_ns == SAMPLE_FAST) - return; /* We don't need the timer to trigger in continuous mode. */ - - /* An ADC conversion takes 1.1667us, so to be sure we don't get data overruns we limit sampling to every 1.5us. - Since we don't have a spare PLL to generate the ADC sample clock and re-configuring the system clock just for this - would be overkill we round to 250ns increments. The minimum sampling rate is about 60Hz due to timer resolution. */ - int cycles = sampling_interval_ns > 1500 ? sampling_interval_ns/250 : 6; - if (cycles > 0xffff) - cycles = 0xffff; - adc_timer_init(12/*250ns/tick*/, cycles); -} - -/* FIXME figure out the proper place to configure this. */ -#define ADC_TIMER_INTERVAL_US 20 - -/* Regular operation receiver mode. */ -void adc_configure_monitor_mode(const struct command_if_def *cmd_if) { - /* First, disable trigger timer, DMA and ADC in case we're reconfiguring on the fly. */ - TIM1->CR1 &= ~TIM_CR1_CEN; - ADC1->CR &= ~ADC_CR_ADSTART; - DMA1_Channel1->CCR &= ~DMA_CCR_EN; - - /* keep track of current mode in global variable */ - st.adc_mode = ADC_MONITOR; - - for (int i=0; i<NCH; i++) - st.adc_aggregate[i] = 0; - st.mean_aggregator[0] = st.mean_aggregator[1] = st.mean_aggregator[2] = 0; - st.mean_aggregate_ctr = 0; - - st.det_st.hysteresis_mv = 6000; - /* base_cycles * the ADC timer interval (20us) must match the driver's AC period. */ - st.det_st.base_interval_cycles = 40; /* 40 * 20us = 800us/1.25kHz */ - - st.det_st.sync = 0; - st.det_st.last_bit = 0; - st.det_st.committed_len_ctr = st.det_st.len_ctr = 0; - xfr_8b10b_reset((struct state_8b10b_dec *)&st.det_st.rx8b10b); - reset_receiver((struct proto_rx_st *)&st.det_st.rx_st, cmd_if); - - adc_dma_init(NCH, true); - - /* Setup DMA and triggering: Trigger from Timer 1 Channel 4 */ - ADC1->CFGR1 = ADC_CFGR1_DMAEN | ADC_CFGR1_DMACFG | (2<<ADC_CFGR1_EXTEN_Pos) | (1<<ADC_CFGR1_EXTSEL_Pos); - /* Clock from PCLK/4 instead of the internal exclusive high-speed RC oscillator. */ - ADC1->CFGR2 = (2<<ADC_CFGR2_CKMODE_Pos); /* Use PCLK/4=12MHz */ - /* Sampling time 13.5 ADC clock cycles -> total conversion time 2.17us*/ - ADC1->SMPR = (2<<ADC_SMPR_SMP_Pos); - /* Internal VCC and temperature sensor channels */ - ADC1->CHSELR = ADC_CHSELR_CHSEL0 | ADC_CHSELR_CHSEL1 | ADC_CHSELR_CHSEL16 | ADC_CHSELR_CHSEL17; - /* Enable internal voltage reference and temperature sensor */ - ADC->CCR = ADC_CCR_TSEN | ADC_CCR_VREFEN; - /* Perform ADC calibration */ - ADC1->CR |= ADC_CR_ADCAL; - while (ADC1->CR & ADC_CR_ADCAL) - ; - /* Enable ADC */ - ADC1->CR |= ADC_CR_ADEN; - ADC1->CR |= ADC_CR_ADSTART; - - /* Initialize the timer. Set the divider to get a nice round microsecond tick. The interval must be long enough to - * comfortably fit all conversions inside. There should be some margin since the ADC runs off its own internal RC - * oscillator and will drift w.r.t. the system clock. 20us is a nice value when four channels are selected (A, B, - * T and V). - */ - adc_timer_init(SystemCoreClock/1000000/*1.0us/tick*/, 20/* us */); -} - -static void adc_dma_init(int burstlen, bool enable_interrupt) { - /* Configure DMA 1 Channel 1 to get rid of all the data */ - DMA1_Channel1->CPAR = (unsigned int)&ADC1->DR; - DMA1_Channel1->CMAR = (unsigned int)&adc_buf; - DMA1_Channel1->CNDTR = burstlen; - DMA1_Channel1->CCR = (0<<DMA_CCR_PL_Pos); - DMA1_Channel1->CCR |= - DMA_CCR_CIRC /* circular mode so we can leave it running indefinitely */ - | (1<<DMA_CCR_MSIZE_Pos) /* 16 bit */ - | (1<<DMA_CCR_PSIZE_Pos) /* 16 bit */ - | DMA_CCR_MINC - | (enable_interrupt ? DMA_CCR_TCIE : 0); /* Enable transfer complete interrupt. */ - - if (enable_interrupt) { - /* triggered on transfer completion. We use this to process the ADC data */ - NVIC_EnableIRQ(DMA1_Channel1_IRQn); - NVIC_SetPriority(DMA1_Channel1_IRQn, 2<<5); - } else { - NVIC_DisableIRQ(DMA1_Channel1_IRQn); - DMA1->IFCR |= DMA_IFCR_CGIF1; - } - - DMA1_Channel1->CCR |= DMA_CCR_EN; /* Enable channel */ -} - -static void adc_timer_init(int psc, int ivl) { - TIM1->BDTR = TIM_BDTR_MOE; /* MOE is needed even though we only "output" a chip-internal signal TODO: Verify this. */ - TIM1->CCMR2 = (6<<TIM_CCMR2_OC4M_Pos); /* PWM Mode 1 to get a clean trigger signal */ - TIM1->CCER = TIM_CCER_CC4E; /* Enable capture/compare unit 4 connected to ADC */ - TIM1->CCR4 = 1; /* Trigger at start of timer cycle */ - /* Set prescaler and interval */ - TIM1->PSC = psc-1; - TIM1->ARR = ivl-1; - /* Preload all values */ - TIM1->EGR |= TIM_EGR_UG; - TIM1->CR1 = TIM_CR1_ARPE; - /* And... go! */ - TIM1->CR1 |= TIM_CR1_CEN; -} - -/* This acts as a no-op that provides a convenient point to set a breakpoint for the debug scope logic */ -static void gdb_dump(void) { -} - -/* Called on reception of a bit. This feeds the bit to the 8b10b state machine. When the 8b10b state machine recognizes - * a received symbol, this in turn calls receive_symbol. Since this is called at sampling time roughly halfway into a - * bit being received, receive_symbol is called roughly half-way through the last bit of the symbol, just before the - * symbol's end. - */ -void receive_bit(struct bit_detector_st *st, int bit) { - int symbol = xfr_8b10b_feed_bit((struct state_8b10b_dec *)&st->rx8b10b, bit); - if (symbol == -K28_1) - st->sync = 1; - - if (symbol == -DECODING_IN_PROGRESS) - return; - - if (symbol == -DECODING_ERROR) - st->sync = 0; - /* Fall through so we also pass the error to receive_symbol */ - - receive_symbol(&st->rx_st, symbol); - - /* Exceedingly handy piece of debug code: The Debug Scope 2000 (TM) */ - /* - static int debug_buf_pos = 0; - if (st->sync) { - if (debug_buf_pos < NCH) { - debug_buf_pos = NCH; - } else { - adc_buf[debug_buf_pos++] = symbol; - - if (debug_buf_pos >= sizeof(adc_buf)/sizeof(adc_buf[0])) { - debug_buf_pos = 0; - st->sync = 0; - gdb_dump(); - for (int i=0; i<sizeof(adc_buf)/sizeof(adc_buf[0]); i++) - adc_buf[i] = -255; - } - } - } - */ -} - -/* From a series of detected line levels, extract discrete bits. This self-synchronizes to signal transitions. This - * expects base_interval_cycles to be set correctly. When a bit is detected, this calls receive_bit(st, bit). The call - * to receive_bit happens at the sampling point about half-way through the bit being received. - */ -void bit_detector(struct bit_detector_st *st, int a) { - int new_bit = st->last_bit; - int diff = a-5500; /* FIXME extract constants */ - if (diff < - st->hysteresis_mv/2) - new_bit = 0; - else if (diff > st->hysteresis_mv/2) - new_bit = 1; - else - blank(); /* Safety, in case we get an unexpected transition */ - - st->len_ctr++; - if (new_bit != st->last_bit) { /* On transition */ - st->last_bit = new_bit; - st->len_ctr = 0; - st->committed_len_ctr = st->base_interval_cycles>>1; /* Commit first half of bit */ - - } else if (st->len_ctr >= st->committed_len_ctr) { - /* The line stayed constant for a longer interval than the commited length. Interpret this as a transmitted bit. - * - * +-- Master clock edges -->| - - - - |<-- One bit period - * | | | - * 1 X X X X X X X X - * ____/^^^^*^^^^\_______________________________________/^^^^*^^^^^^^^^*^^^^\__________________________________ - * 0 v ^ v ^ - * | | | | - * | +-------------------------------+ +---------+ - * | | | - * At this point, commit 1/2 bit (until here). This When we arrive at the committed value, commit next - * happens in the block above. full bit as we're now right in the middle of the - * first bit. This happens in the line below. - */ - - /* Commit second half of this and first half of possible next bit */ - st->committed_len_ctr += st->base_interval_cycles; - receive_bit(st, st->last_bit); - } -} - -void DMA1_Channel1_IRQHandler(void) { - /* ISR timing measurement for debugging */ - //int start = SysTick->VAL; - - /* Clear the interrupt flag */ - DMA1->IFCR |= DMA_IFCR_CGIF1; - - if (st.adc_mode == ADC_SCOPE) - return; - - /* FIXME This code section currently is a mess since I left it as soon as it worked. Re-work this and try to get - * back all the useful monitoring stuff, in particular temperature. */ - - /* This has been copied from the code examples to section 12.9 ADC>"Temperature sensor and internal reference - * voltage" in the reference manual with the extension that we actually measure the supply voltage instead of - * hardcoding it. This is not strictly necessary since we're running off a bored little LDO but it's free and - * the current supply voltage is a nice health value. - */ - // FIXME DEBUG adc_data.vcc_mv = (3300 * VREFINT_CAL)/(st.adc_aggregate[VREF_CH]); - - int64_t vcc = 3300; - /* FIXME debug - int64_t vcc = adc_data.vcc_mv; - int64_t read = st.adc_aggregate[TEMP_CH] * 10 * 10000; - int64_t cal = TS_CAL1 * 10 * 10000; - adc_data.temp_celsius_tenths = 300 + ((read/4096 * vcc) - (cal/4096 * 3300))/43000; - */ - - /* Calculate the line voltage from the measured ADC voltage and the used resistive divider ratio */ - const long vmeas_r_total = VMEAS_R_HIGH + VMEAS_R_LOW; - //int a = adc_data.vmeas_a_mv = (st.adc_aggregate[VMEAS_A]*(vmeas_r_total * vcc / VMEAS_R_LOW)) >> 12; - int a = adc_data.vmeas_a_mv = (adc_buf[VMEAS_A]*13300) >> 12; - bit_detector((struct bit_detector_st *)&st.det_st, a); - - /* ISR timing measurement for debugging */ - /* - int end = SysTick->VAL; - int tdiff = start - end; - if (tdiff < 0) - tdiff += SysTick->LOAD; - st.dma_isr_duration = tdiff; - */ -} - |