work on ADC sampling, not tested, missing commands

platform/hw_utils.c

@@ -349,6 +349,9 @@ bool solve_timer(uint32_t base_freq, uint32_t required_freq, bool is16bit,
                  uint16_t *presc, uint32_t *count, float *real_freq)
 {
     if (required_freq == 0) return false;
+
+    // XXX consider using the LL macros __LL_TIM_CALC_PSC and __LL_TIM_CALC_ARR
+
     const float fPresc = base_freq / required_freq;
     uint32_t wCount = (uint32_t) lrintf(fPresc);
 

platform/hw_utils.h

@@ -183,4 +183,16 @@ void hw_periph_clock_disable(void *periph);
 bool solve_timer(uint32_t base_freq, uint32_t required_freq, bool is16bit,
                  uint16_t *presc, uint32_t *count, float *real_freq);
 
+#define hw_wait_while(call, timeout) \
+    do { \
+        uint32_t _ts = HAL_GetTick(); \
+        while (1 == (call)) { \
+            if (HAL_GetTick() - _ts > (timeout)) { \
+                trap("Timeout"); \
+            } \
+        } \
+    } while (0)
+
+#define hw_wait_until(call, timeout) hw_wait_while(!(call), (timeout))
+
 #endif //GEX_PIN_UTILS_H

platform/irq_dispatcher.c

@@ -65,6 +65,8 @@ static struct callbacks_ {
     struct cbslot tim7;
     struct cbslot tim15;
 
+    struct cbslot adc1;
+
     // XXX add more callbacks here when needed
 } callbacks;
 
@@ -96,7 +98,9 @@ void irqd_init(void)
     HAL_NVIC_SetPriority(DMA1_Channel2_3_IRQn, 2, 0);
     HAL_NVIC_SetPriority(DMA1_Channel4_5_6_7_IRQn, 2, 0);
 
-//    NVIC_EnableIRQ(ADC1_COMP_IRQn);             /*!< ADC1 and COMP interrupts (ADC interrupt combined with EXTI Lines 21 and 22 */
+    NVIC_EnableIRQ(ADC1_COMP_IRQn);             /*!< ADC1 and COMP interrupts (ADC interrupt combined with EXTI Lines 21 and 22 */
+    HAL_NVIC_SetPriority(ADC1_COMP_IRQn, 1, 0); // ADC group completion - higher prio than DMA to let it handle the last halfword first
+
 //    NVIC_EnableIRQ(TIM1_IRQn);                  /*!< TIM1 global Interrupt                                          */
 //    NVIC_EnableIRQ(TIM2_IRQn);                  /*!< TIM2 global Interrupt                                           */
 //    NVIC_EnableIRQ(TIM3_IRQn);                  /*!< TIM3 global Interrupt                                           */
@@ -159,6 +163,8 @@ static struct cbslot *get_slot_for_periph(void *periph)
     else if (periph == TIM7) slot = &callbacks.tim7;
     else if (periph == TIM15) slot = &callbacks.tim15;
 
+    else if (periph == ADC1) slot = &callbacks.adc1;
+
     else if (periph >= EXTIS[0] && periph <= EXTIS[15]) {
         slot = &callbacks.exti[periph - EXTIS[0]];
     }
@@ -313,6 +319,11 @@ void TIM15_IRQHandler(void)
     CALL_IRQ_HANDLER(callbacks.tim15);
 }
 
+void ADC1_COMP_IRQHandler(void)
+{
+    CALL_IRQ_HANDLER(callbacks.adc1);
+}
+
 
 // other ISRs...
 

platform/plat_init.c

@@ -18,6 +18,8 @@
 
 void plat_init(void)
 {
+    // GPIO clocks are enabled earlier in the GEX start-up hook
+
     // Load system defaults
     systemsettings_init();
 
@@ -27,8 +29,9 @@ void plat_init(void)
 
     LockJumper_Init();
     Indicator_Init();
-    DebugUart_Init(); // resource claim
+    DebugUart_Init(); // resource claim (was inited earlier to allow debug outputs)
 
+    // Enable interrupts and set priorities
     irqd_init();
 
     dbg("Loading settings ...");

units/adc/_adc_core.c

@@ -2,3 +2,270 @@
 // Created by MightyPork on 2018/02/04.
 //
 
+#include "platform.h"
+#include "unit_base.h"
+
+#define ADC_INTERNAL
+#include "_adc_internal.h"
+
+void UADC_DMA_Handler(void *arg)
+{
+    Unit *unit = arg;
+
+    assert_param(unit);
+    struct priv *priv = unit->data;
+    assert_param(priv);
+
+    const uint32_t isrsnapshot = priv->DMAx->ISR;
+
+    if (LL_DMA_IsActiveFlag_G(isrsnapshot, priv->dma_chnum)) {
+        const bool tc = LL_DMA_IsActiveFlag_TC(isrsnapshot, priv->dma_chnum);
+        const bool ht = LL_DMA_IsActiveFlag_HT(isrsnapshot, priv->dma_chnum);
+        const bool te = LL_DMA_IsActiveFlag_TE(isrsnapshot, priv->dma_chnum);
+
+        // check what mode we're in
+        const bool m_trig = priv->opmode == ADC_OPMODE_TRIGD;
+        const bool m_stream = priv->opmode == ADC_OPMODE_STREAM;
+        const bool m_fixcpt = priv->opmode == ADC_OPMODE_FIXCAPT;
+
+        if (m_trig || m_stream || m_fixcpt) {
+            if (ht || tc) {
+                const uint16_t start = priv->stream_startpos;
+                uint16_t end;
+
+                if (ht) {
+                    dbg("HT");
+                    end = (uint16_t) (priv->dma_buffer_itemcount / 2);
+                    LL_DMA_ClearFlag_HT(priv->DMAx, priv->dma_chnum);
+                }
+                else {
+                    dbg("TC");
+                    end = (uint16_t) priv->dma_buffer_itemcount;
+                    LL_DMA_ClearFlag_TC(priv->DMAx, priv->dma_chnum);
+                }
+
+                assert_param(start < end);
+
+                uint32_t sgcount = (end - start) / priv->nb_channels;
+
+                if (m_trig || m_fixcpt) {
+                    sgcount = MIN(priv->trig_stream_remain, sgcount);
+                    priv->trig_stream_remain -= sgcount;
+                }
+
+                dbg("Would send %d groups (u16 offset %d -> %d)", (int)sgcount, (int)start, (int)(start+sgcount*priv->nb_channels));
+                // TODO send the data together with remaining count (used to detect end of transmission)
+
+                if (m_trig || m_fixcpt) {
+                    if (priv->trig_stream_remain == 0) {
+                        dbg("End of capture");
+                        UADC_SwitchMode(unit, (priv->auto_rearm && m_trig) ? ADC_OPMODE_ARMED : ADC_OPMODE_IDLE);
+                    }
+                }
+
+                if (end == priv->dma_buffer_itemcount) {
+                    priv->stream_startpos = 0;
+                }
+                else {
+                    priv->stream_startpos = end;
+                }
+            }
+        } else {
+            // This shouldn't happen, the interrupt should be disabled in this opmode
+            dbg("(!) not streaming, DMA IT should be disabled");
+
+            if (ht) {
+                LL_DMA_ClearFlag_HT(priv->DMAx, priv->dma_chnum);
+            }
+            else {
+                LL_DMA_ClearFlag_TC(priv->DMAx, priv->dma_chnum);
+            }
+        }
+
+        if (te) {
+            // this shouldn't happen - error
+            dbg("ADC DMA TE!");
+            LL_DMA_ClearFlag_TE(priv->DMAx, priv->dma_chnum);
+        }
+    }
+}
+
+void UADC_ADC_EOS_Handler(void *arg)
+{
+    uint64_t timestamp = PTIM_GetMicrotime();
+    Unit *unit = arg;
+
+    dbg("ADC EOS ISR hit");
+    assert_param(unit);
+    struct priv *priv = unit->data;
+    assert_param(priv);
+
+    // Wait for the DMA to complete copying the last sample
+    while (priv->DMA_CHx->CNDTR % priv->nb_channels != 0);
+
+    uint32_t sample_pos;
+    if (priv->DMA_CHx->CNDTR == 0) {
+        sample_pos = (uint32_t) (priv->dma_buffer_itemcount - 1);
+    } else {
+        sample_pos = priv->DMA_CHx->CNDTR;
+    }
+    sample_pos -= priv->nb_channels;
+    dbg("Sample pos %d", (int)sample_pos);
+
+    for (uint32_t i = 0; i < 18; i++) {
+        if (priv->extended_channels_mask & (1 << i)) {
+            uint16_t val = priv->dma_buffer[sample_pos];
+            dbg("Trig line level %d", (int)val);
+
+            if (priv->enable_averaging) {
+                priv->averaging_bins[i] =
+                    priv->averaging_bins[i] * (1.0f - priv->avg_factor_as_float) +
+                    ((float) val) * priv->avg_factor_as_float;
+            } else {
+                priv->last_sample[i] = val;
+            }
+
+            if (priv->opmode == ADC_OPMODE_ARMED) {
+                if (i == priv->trigger_source) {
+                    bool trigd = false;
+                    bool rising = false;
+                    if (priv->trig_prev_level < priv->trig_level && val >= priv->trig_level) {
+                        dbg("******** Rising edge");
+                        // Rising edge
+                        trigd = (bool) (priv->trig_edge & 0b01);
+                        rising = true;
+                    }
+                    else if (priv->trig_prev_level > priv->trig_level && val <= priv->trig_level) {
+                        dbg("******** Falling edge");
+                        // Falling edge
+                        trigd = (bool) (priv->trig_edge & 0b10);
+                    }
+
+                    if (trigd) {
+                        UADC_HandleTrigger(unit, rising, timestamp);
+                    }
+
+                    priv->trig_prev_level = val;
+                }
+            }
+        }
+    }
+
+    dbg("  EOS ISR end.");
+}
+
+void UADC_HandleTrigger(Unit *unit, bool rising, uint64_t timestamp)
+{
+    assert_param(unit);
+    struct priv *priv = unit->data;
+    assert_param(priv);
+
+    if (priv->trig_holdoff != 0 && priv->trig_holdoff_remain > 0) {
+        dbg("Trig discarded due to holdoff.");
+        return;
+    }
+
+    if (priv->trig_holdoff > 0) {
+        priv->trig_holdoff_remain = priv->trig_holdoff;
+        // Start the tick
+        unit->tick_interval = 1;
+        unit->_tick_cnt = 0;
+    }
+
+    dbg("Trigger condition hit, rising=%d", rising);
+    // TODO Send pre-trigger
+
+    priv->stream_startpos = (uint16_t) priv->DMA_CHx->CNDTR;
+    priv->trig_stream_remain = priv->trig_len;
+    UADC_SwitchMode(unit, ADC_OPMODE_TRIGD);
+}
+
+void UADC_updateTick(Unit *unit)
+{
+    assert_param(unit);
+    struct priv *priv = unit->data;
+    assert_param(priv);
+
+    if (priv->trig_holdoff_remain > 0) {
+        priv->trig_holdoff_remain--;
+
+        if (priv->trig_holdoff_remain == 0) {
+            unit->tick_interval = 0;
+            unit->_tick_cnt = 0;
+        }
+    }
+}
+
+void UADC_SwitchMode(Unit *unit, enum uadc_opmode new_mode)
+{
+    assert_param(unit);
+    struct priv *priv = unit->data;
+    assert_param(priv);
+
+    if (new_mode == priv->opmode) return; // nothing to do
+
+    // if un-itied, can go only to IDLE
+    assert_param((priv->opmode != ADC_OPMODE_UNINIT) || (new_mode == ADC_OPMODE_IDLE));
+
+    if (new_mode == ADC_OPMODE_UNINIT) {
+        dbg("ADC switch -> UNINIT");
+        // Stop the DMA, timer and disable ADC - this is called before tearing down the unit
+        LL_TIM_DisableCounter(priv->TIMx);
+
+        // Switch off the ADC
+        if (LL_ADC_IsEnabled(priv->ADCx)) {
+            // Cancel ongoing conversion
+            if (LL_ADC_REG_IsConversionOngoing(priv->ADCx)) {
+                dbg("Stopping ADC conv");
+                LL_ADC_REG_StopConversion(priv->ADCx);
+                hw_wait_while(LL_ADC_REG_IsStopConversionOngoing(priv->ADCx), 100);
+            }
+
+            LL_ADC_Disable(priv->ADCx);
+            dbg("Disabling ADC");
+            hw_wait_while(LL_ADC_IsDisableOngoing(priv->ADCx), 100);
+        }
+
+        dbg("Disabling DMA");
+        LL_DMA_DisableChannel(priv->DMAx, priv->dma_chnum);
+        LL_DMA_DisableIT_HT(priv->DMAx, priv->dma_chnum);
+        LL_DMA_DisableIT_TC(priv->DMAx, priv->dma_chnum);
+    }
+    else if (new_mode == ADC_OPMODE_IDLE) {
+        dbg("ADC switch -> IDLE");
+        // IDLE and ARMED are identical with the exception that the trigger condition is not checked
+
+        // In IDLE, we don't need the DMA interrupts
+        LL_DMA_DisableIT_HT(priv->DMAx, priv->dma_chnum);
+        LL_DMA_DisableIT_TC(priv->DMAx, priv->dma_chnum);
+
+        // Use End Of Sequence to recover results for averaging from the DMA buffer and DR
+        LL_ADC_EnableIT_EOS(priv->ADCx);
+
+        if (priv->opmode == ADC_OPMODE_UNINIT) {
+            // Nothing is started yet - this is the only way to leave UNINIT
+            LL_ADC_Enable(priv->ADCx);
+            LL_DMA_EnableChannel(priv->DMAx, priv->dma_chnum);
+            LL_TIM_EnableCounter(priv->TIMx);
+        }
+    }
+    else if (new_mode == ADC_OPMODE_ARMED) {
+        dbg("ADC switch -> ARMED");
+        assert_param(priv->opmode == ADC_OPMODE_IDLE);
+        // there's nothing else to do here
+    }
+    else if (new_mode == ADC_OPMODE_TRIGD || new_mode == ADC_OPMODE_STREAM) {
+        dbg("ADC switch -> TRIG'D or STREAM");
+        assert_param(priv->opmode == ADC_OPMODE_ARMED || priv->opmode == ADC_OPMODE_IDLE);
+
+        // during the capture, we disallow direct readout and averaging to reduce overhead
+        LL_ADC_DisableIT_EOS(priv->ADCx);
+
+        // Enable the DMA buffer interrupts
+        LL_DMA_EnableIT_HT(priv->DMAx, priv->dma_chnum);
+        LL_DMA_EnableIT_TC(priv->DMAx, priv->dma_chnum);
+    }
+
+    // the actual switch
+    priv->opmode = new_mode;
+}

units/adc/_adc_init.c

@@ -2,6 +2,7 @@
 // Created by MightyPork on 2018/02/03.
 //
 
+#include <stm32f072xb.h>
 #include "platform.h"
 #include "unit_base.h"
 
@@ -20,48 +21,12 @@ error_t UADC_preInit(Unit *unit)
     priv->sample_time = 0b010; // 13.5c
     priv->frequency = 1000;
     priv->buffer_size = 512;
+    priv->enable_averaging = false;
+    priv->averaging_factor = 500;
 
-    return E_SUCCESS;
-}
-
-static void UADC_DMA_Handler(void *arg)
-{
-    Unit *unit = arg;
-
-    dbg("ADC DMA ISR hit");
-    assert_param(unit);
-    struct priv *priv = unit->data;
-    assert_param(priv);
-
-    const uint32_t isrsnapshot = priv->DMAx->ISR;
-
-    if (LL_DMA_IsActiveFlag_G(isrsnapshot, priv->dma_chnum)) {
-        bool tc = LL_DMA_IsActiveFlag_TC(isrsnapshot, priv->dma_chnum);
-        bool ht = LL_DMA_IsActiveFlag_HT(isrsnapshot, priv->dma_chnum);
-
-        // Here we have to either copy it somewhere else, or notify another thread (queue?)
-        // that the data is ready for reading
-
-        if (ht) {
-            uint16_t start = 0;
-            uint16_t end = (uint16_t) (priv->dma_buffer_size / 2);
-            // TODO handle first half
-            LL_DMA_ClearFlag_HT(priv->DMAx, priv->dma_chnum);
-        }
-
-        if (tc) {
-            uint16_t start = (uint16_t) (priv->dma_buffer_size / 2);
-            uint16_t end = (uint16_t) priv->dma_buffer_size;
-            // TODO handle second half
-            LL_DMA_ClearFlag_TC(priv->DMAx, priv->dma_chnum);
-        }
+    priv->opmode = ADC_OPMODE_UNINIT;
 
-        if (LL_DMA_IsActiveFlag_TE(isrsnapshot, priv->dma_chnum)) {
-            // this shouldn't happen - error
-            dbg("ADC DMA TE!");
-            LL_DMA_ClearFlag_TE(priv->DMAx, priv->dma_chnum);
-        }
-    }
+    return E_SUCCESS;
 }
 
 /** Finalize unit set-up */
@@ -133,6 +98,7 @@ error_t UADC_init(Unit *unit)
         // enable peripherals clock
         hw_periph_clock_enable(priv->ADCx);
         hw_periph_clock_enable(priv->TIMx);
+        // DMA and GPIO clocks are enabled on startup automatically
     }
 
     // ------------------- CONFIGURE THE TIMER --------------------------
@@ -142,8 +108,7 @@ error_t UADC_init(Unit *unit)
         uint16_t presc;
         uint32_t count;
         float real_freq;
-        if (!solve_timer(PLAT_APB1_HZ, priv->frequency, true, &presc, &count,
-                         &real_freq)) {
+        if (!solve_timer(PLAT_APB1_HZ, priv->frequency, true, &presc, &count, &real_freq)) {
             dbg("Failed to resolve timer params.");
             return E_BAD_VALUE;
         }
@@ -167,24 +132,29 @@ error_t UADC_init(Unit *unit)
         while (LL_ADC_IsCalibrationOnGoing(priv->ADCx)) {}
         dbg("ADC calibrated.");
 
-        uint32_t mask = 0;
-        if (priv->enable_vref) mask |= LL_ADC_PATH_INTERNAL_VREFINT;
-        if (priv->enable_tsense) mask |= LL_ADC_PATH_INTERNAL_TEMPSENSOR;
-        LL_ADC_SetCommonPathInternalCh(priv->ADCx_Common, mask);
+        {
+            uint32_t mask = 0;
+            if (priv->enable_vref) mask |= LL_ADC_PATH_INTERNAL_VREFINT;
+            if (priv->enable_tsense) mask |= LL_ADC_PATH_INTERNAL_TEMPSENSOR;
+            LL_ADC_SetCommonPathInternalCh(priv->ADCx_Common, mask);
+        }
+
         LL_ADC_SetDataAlignment(priv->ADCx, LL_ADC_DATA_ALIGN_RIGHT);
         LL_ADC_SetResolution(priv->ADCx, LL_ADC_RESOLUTION_12B);
         LL_ADC_REG_SetDMATransfer(priv->ADCx, LL_ADC_REG_DMA_TRANSFER_UNLIMITED);
 
         // configure channels
-        LL_ADC_REG_SetSequencerChannels(priv->ADCx, priv->channels);
-        if (priv->enable_tsense) LL_ADC_REG_SetSequencerChAdd(priv->ADCx, LL_ADC_CHANNEL_TEMPSENSOR);
-        if (priv->enable_vref) LL_ADC_REG_SetSequencerChAdd(priv->ADCx, LL_ADC_CHANNEL_VREFINT);
+        priv->extended_channels_mask = priv->channels;
+        if (priv->enable_tsense) priv->extended_channels_mask |= (1<<16);
+        if (priv->enable_vref) priv->extended_channels_mask |= (1<<17);
+
+        priv->ADCx->CHSELR = priv->extended_channels_mask;
 
         LL_ADC_REG_SetTriggerSource(priv->ADCx, LL_ADC_REG_TRIG_EXT_TIM15_TRGO);
 
         LL_ADC_SetSamplingTimeCommonChannels(priv->ADCx, LL_ADC_SAMPLETIMES[priv->sample_time]);
 
-        LL_ADC_Enable(priv->ADCx);
+//        LL_ADC_Enable(priv->ADCx);
     }
 
     // --------------------- CONFIGURE DMA -------------------------------
@@ -193,10 +163,14 @@ error_t UADC_init(Unit *unit)
         // The length must be a 2*multiple of the number of channels, in bytes
         uint16_t itemcount = (uint16_t) ((priv->nb_channels) * (uint16_t) (priv->buffer_size / (2 * priv->nb_channels)));
         if (itemcount % 2 == 1) itemcount -= priv->nb_channels;
-        priv->dma_buffer_size = (uint16_t) (itemcount * 2);
-        dbg("DMA item count is %d (%d bytes)", itemcount, priv->dma_buffer_size);
+        priv->dma_buffer_itemcount = itemcount;
+
+        dbg("DMA item count is %d (%d bytes), There are %d 2-byte samples per group.",
+            priv->dma_buffer_itemcount,
+            priv->dma_buffer_itemcount*sizeof(uint16_t),
+            priv->nb_channels);
 
-        priv->dma_buffer = malloc_ck(priv->dma_buffer_size);
+        priv->dma_buffer = malloc_ck(priv->dma_buffer_itemcount * sizeof(uint16_t));
         if (NULL == priv->dma_buffer) return E_OUT_OF_MEM;
         assert_param(((uint32_t) priv->dma_buffer & 3) == 0); // must be aligned
 
@@ -218,21 +192,25 @@ error_t UADC_init(Unit *unit)
 
             assert_param(SUCCESS == LL_DMA_Init(priv->DMAx, priv->dma_chnum, &init));
 
-            irqd_attach(priv->DMA_CHx, UADC_DMA_Handler, unit);
             // Interrupt on transfer 1/2 and complete
             // We will capture the first and second half and send it while the other half is being filled.
-            LL_DMA_EnableIT_HT(priv->DMAx, priv->dma_chnum);
-            LL_DMA_EnableIT_TC(priv->DMAx, priv->dma_chnum);
+//            LL_DMA_EnableIT_HT(priv->DMAx, priv->dma_chnum);
+//            LL_DMA_EnableIT_TC(priv->DMAx, priv->dma_chnum);
         }
 
         LL_DMA_EnableChannel(priv->DMAx, priv->dma_chnum);
     }
 
-    dbg("ADC inited, starting the timer ...");
+    // prepare the avg factor float for the ISR
+    if (priv->averaging_factor > 1000) priv->averaging_factor = 1000; // normalize
+    priv->avg_factor_as_float = priv->averaging_factor/1000.0f;
+
+    dbg("ADC peripherals configured.");
 
-    // FIXME - temporary demo - counter start...
-    LL_ADC_REG_StartConversion(priv->ADCx); // the first conversion must be started manually
-    LL_TIM_EnableCounter(priv->TIMx);
+    irqd_attach(priv->DMA_CHx, UADC_DMA_Handler, unit);
+    irqd_attach(priv->ADCx, UADC_ADC_EOS_Handler, unit);
+
+    UADC_SwitchMode(unit, ADC_OPMODE_IDLE);
 
     return E_SUCCESS;
 }
@@ -246,11 +224,15 @@ void UADC_deInit(Unit *unit)
 
     // de-init peripherals
     if (unit->status == E_SUCCESS ) {
+        UADC_SwitchMode(unit, ADC_OPMODE_UNINIT);
+
         //LL_ADC_DeInit(priv->ADCx);
         LL_ADC_CommonDeInit(priv->ADCx_Common);
         LL_TIM_DeInit(priv->TIMx);
 
         irqd_detach(priv->DMA_CHx, UADC_DMA_Handler);
+        irqd_detach(priv->ADCx, UADC_ADC_EOS_Handler);
+
         LL_DMA_DeInit(priv->DMAx, priv->dma_chnum);
 
         free_ck(priv->dma_buffer);

units/adc/_adc_internal.h

@@ -11,36 +11,60 @@
 
 #include "unit_base.h"
 
+enum uadc_opmode {
+    ADC_OPMODE_UNINIT, //!< Not yet switched to any mode
+    ADC_OPMODE_IDLE,   //!< Idle, each sample overwrites the previous. Allows immediate value readout and averaging.
+    ADC_OPMODE_ARMED,  //!< Armed for a trigger. Direct access and averaging are disabled.
+    ADC_OPMODE_TRIGD,  //!< Triggered, sending pre-trigger and streaming captured data.
+    ADC_OPMODE_FIXCAPT,//!< Capture of fixed length without a trigger
+    ADC_OPMODE_STREAM, //!< Unlimited capture
+};
+
 /** Private data structure */
 struct priv {
     // settings
     uint16_t channels;    //!< bit flags (will be recorded in order 0-15)
     bool enable_tsense;   //!< append a signal from the temperature channel (voltage proportional to Tj)
-    bool enable_vref;  //!< append a signal from the internal voltage reference
+    bool enable_vref;     //!< append a signal from the internal voltage reference
     uint8_t sample_time;  //!< 0-7 (corresponds to 1.5-239.5 cycles) - time for the sampling capacitor to charge
     uint32_t frequency;   //!< Timer frequency in Hz. Note: not all frequencies can be achieved accurately
     uint16_t buffer_size; //!< Buffer size in bytes (count 2 bytes per channel per measurement) - faster sampling freq needs bigger buffer
 
-    // TODO averaging (maybe a separate component?)
-    // TODO threshold watchdog with hysteresis (maybe a separate component?)
-    // TODO trigger level, edge direction, hold-off, pre-trigger buffer (extract from the DMA buffer)
+    bool enable_averaging;   //!< Enable exponential averaging
+    uint16_t averaging_factor;  //!< Exponential averaging factor 0-1000
 
     // internal state
-    ADC_TypeDef *ADCx;
-    ADC_Common_TypeDef *ADCx_Common;
-    TIM_TypeDef *TIMx;
-    DMA_TypeDef *DMAx;
-    uint8_t dma_chnum;
-    DMA_Channel_TypeDef *DMA_CHx;
-    uint16_t *dma_buffer;
-    uint8_t nb_channels; // nr of enabled adc channels
-    uint16_t dma_buffer_size; // real number of bytes
+    uint32_t extended_channels_mask; //!< channels bitfield including tsense and vref
+    float avg_factor_as_float;
+    ADC_TypeDef *ADCx; //!< The ADC peripheral used
+    ADC_Common_TypeDef *ADCx_Common; //!< The ADC common control block
+    TIM_TypeDef *TIMx; //!< ADC timing timer instance
+    DMA_TypeDef *DMAx; //!< DMA isnatnce used
+    uint8_t dma_chnum; //!< DMA channel number
+    DMA_Channel_TypeDef *DMA_CHx; //!< DMA channel instance
+    uint16_t *dma_buffer;     //!< malloc'd buffer for the samples
+    uint8_t nb_channels;      //!< nbr of enabled adc channels
+    uint16_t dma_buffer_itemcount; //!< real size of the buffer (adjusted from the configured size to evenly encompass 2*size of one sample)
+
+    enum uadc_opmode opmode;  //!< OpMode (state machine state)
+    union {
+        float averaging_bins[18]; //!< Averaging buffers, enough space to accommodate all channels (16 external + 2 internal)
+        uint16_t last_sample[18]; //!< If averaging is disabled, the last captured sample is stored here.
+    };
+    uint8_t trigger_source;   //!< number of the pin selected as a trigger source
+    uint16_t pretrig_len;     //!< Pre-trigger length, nbr of historical samples to report when trigger occurs
+    uint32_t trig_len;        //!< Trigger length, nbr of samples to report AFTER a trigger occurs
+    uint16_t trig_level;      //!< Triggering level in LSB
+    uint16_t trig_prev_level;      //!< Value of the previous sample, used to detect trigger edge
+    uint8_t  trig_edge;       //!< Which edge we want to trigger on. 1-rising, 2-falling, 3-both
+    uint32_t trig_stream_remain;   //!< Counter of samples remaining to be sent in the post-trigger stream
+    bool auto_rearm;          //!< Flag that the trigger should be re-armed after the stream finishes
+    uint16_t trig_holdoff;    //!< Trigger hold-off time, set when configuring the trigger
+    uint16_t trig_holdoff_remain; //!< Tmp counter for the currently active hold-off
+    uint16_t stream_startpos; //!< Byte offset in the DMA buffer where the next capture for a stream should start.
+                              //!<   Updated in TH/TC and on trigger (after the preceding data is sent as a pretrig buffer)
 };
 
-// max size of the DMA buffer. The actual buffer size will be adjusted to accommodate
-// an even number of sample groups (sets of channels)
-#define UADC_DMA_MAX_BUF_LEN 512
-
 /** Allocate data structure and set defaults */
 error_t UADC_preInit(Unit *unit);
 
@@ -66,4 +90,21 @@ error_t UADC_init(Unit *unit);
 /** Tear down the unit */
 void UADC_deInit(Unit *unit);
 
+// ------------------------------------------------------------------------
+
+/** DMA half/complete handler */
+void UADC_DMA_Handler(void *arg);
+
+/** ADC eod of sequence handler */
+void UADC_ADC_EOS_Handler(void *arg);
+
+/** Switch to a different opmode */
+void UADC_SwitchMode(Unit *unit, enum uadc_opmode new_mode);
+
+/** Handle trigger - process pre-trigger and start streaming the requested number of samples */
+void UADC_HandleTrigger(Unit *unit, bool rising, uint64_t timestamp);
+
+/** Handle a periodic tick - expiring the hold-off */
+void UADC_updateTick(Unit *unit);
+
 #endif //GEX_F072_ADC_INTERNAL_H

units/adc/_adc_settings.c

@@ -83,15 +83,16 @@ void UADC_writeIni(Unit *unit, IniWriter *iw)
     struct priv *priv = unit->data;
 
     iw_comment(iw, "Enabled channels, comma separated");
-    iw_comment(iw, "0-7 = A0-A7, 8-9 = B0-B1, 10-15 = C0-C5");
+    iw_comment(iw, "0-7 = A0-A7,  8-9 = B0-B1,  10-15 = C0-C5");
     iw_entry(iw, "channels", "%s", pinmask2str_up(priv->channels, unit_tmp512));
 
-    iw_comment(iw, "Enable Tsense channel");
+    iw_comment(iw, "Enable Tsense channel (#16)");
     iw_entry(iw, "enable_tsense", str_yn(priv->enable_tsense));
 
-    iw_comment(iw, "Enable Vref channel");
+    iw_comment(iw, "Enable Vref channel (#17)");
     iw_entry(iw, "enable_vref", str_yn(priv->enable_tsense));
 
+    iw_cmt_newline(iw);
     iw_comment(iw, "Sampling time (0-7)");
     iw_entry(iw, "sample_time", "%d", (int)priv->sample_time);
 
@@ -103,5 +104,12 @@ void UADC_writeIni(Unit *unit, IniWriter *iw)
     iw_comment(iw, "- the buffer is shared by all channels");
     iw_comment(iw, "- insufficient buffer size can lead to data loss");
     iw_entry(iw, "buffer_size", "%d", (int)priv->buffer_size);
+
+    iw_cmt_newline(iw);
+    iw_comment(iw, "Enable exponential averaging (only when not streaming)");
+    iw_comment(iw, "Used formula: y[t]=(1-k)*y[t-1]+k*u[t]");
+    iw_entry(iw, "averaging", str_yn(priv->enable_averaging));
+    iw_comment(iw, "Averaging factor k (permil, range 0-1000 ~ 0.000-1.000)");
+    iw_entry(iw, "avg_factor", "%d", priv->averaging_factor);
 }
 

units/adc/unit_adc.c

@@ -40,4 +40,5 @@ const UnitDriver UNIT_ADC = {
     .deInit = UADC_deInit,
     // Function
     .handleRequest = UADC_handleRequest,
+    .updateTick = UADC_updateTick,
 };

utils/malloc_safe.c

@@ -5,6 +5,11 @@
 
 void *malloc_ck_do(size_t size,  const char *file, uint32_t line)
 {
+    if (size == 0) {
+        _warn_msg(file, line, "MALLOC OF SIZE 0");
+        return NULL;
+    }
+
     void *mem = pvPortMalloc(size);
     _malloc_trace(size, mem, file, line);
     if (mem == NULL) {
@@ -16,6 +21,7 @@ void *malloc_ck_do(size_t size,  const char *file, uint32_t line)
 void *calloc_ck_do(size_t nmemb, size_t size, const char *file, uint32_t line)
 {
     void *mem = malloc_ck_do(nmemb*size, file, line);
+    if (mem == NULL) return NULL;
     memset(mem, 0, size*nmemb);
     return mem;
 }