fixed buffer sizing and added buf size to config

units/adc/_adc_init.c

@@ -30,7 +30,8 @@ error_t UADC_preInit(Unit *unit)
     priv->enable_tsense = false;
     priv->enable_vref = false;
     priv->sample_time = 0b010; // 13.5c
-    priv->frequency = 4; //1000
+    priv->frequency = 1000;
+    priv->buffer_size = 512;
 
     return E_SUCCESS;
 }
@@ -160,6 +161,7 @@ error_t UADC_init(Unit *unit)
         LL_TIM_SetAutoReload(priv->TIMx, count - 1);
         LL_TIM_EnableARRPreload(priv->TIMx);
         LL_TIM_EnableUpdateEvent(priv->TIMx);
+        LL_TIM_SetTriggerOutput(priv->TIMx, LL_TIM_TRGO_UPDATE);
         LL_TIM_GenerateEvent_UPDATE(priv->TIMx); // load the prescaller value
     }
 
@@ -195,9 +197,9 @@ error_t UADC_init(Unit *unit)
     // --------------------- CONFIGURE DMA -------------------------------
     dbg("Setting up DMA");
     {
-        // The length must be a 2*multiple of the number of channels
-        // this is a horrible way to do it but will work
-        uint16_t itemcount = (uint16_t) (priv->nb_channels * (uint16_t) (UADC_DMA_MAX_BUF_LEN / (2 * priv->nb_channels)));
+        // 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);
 
@@ -236,6 +238,7 @@ error_t UADC_init(Unit *unit)
     dbg("ADC inited, starting the timer ...");
 
     // FIXME - temporary demo - counter start...
+    LL_ADC_REG_StartConversion(priv->ADCx); // the first conversion must be started manually
     LL_TIM_EnableCounter(priv->TIMx);
 
     return E_SUCCESS;
@@ -254,7 +257,7 @@ void UADC_deInit(Unit *unit)
         LL_ADC_CommonDeInit(priv->ADCx_Common);
         LL_TIM_DeInit(priv->TIMx);
 
-        irqd_detach(priv->DMAx, UADC_DMA_Handler);
+        irqd_detach(priv->DMA_CHx, UADC_DMA_Handler);
         LL_DMA_DeInit(priv->DMAx, priv->dma_chnum);
 
         free_ck(priv->dma_buffer);

units/adc/_adc_internal.h

@@ -19,6 +19,7 @@ struct priv {
     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?)

units/adc/_adc_settings.c

@@ -21,6 +21,10 @@ void UADC_loadBinary(Unit *unit, PayloadParser *pp)
     priv->enable_vref = pp_bool(pp);
     priv->sample_time = pp_u8(pp);
     priv->frequency = pp_u32(pp);
+
+    if (version >= 1) {
+        priv->buffer_size = pp_u16(pp);
+    }
 }
 
 /** Write to a binary buffer for storing in Flash */
@@ -28,13 +32,14 @@ void UADC_writeBinary(Unit *unit, PayloadBuilder *pb)
 {
     struct priv *priv = unit->data;
 
-    pb_u8(pb, 0); // version
+    pb_u8(pb, 1); // version
 
     pb_u16(pb, priv->channels);
     pb_bool(pb, priv->enable_tsense);
     pb_bool(pb, priv->enable_vref);
     pb_u8(pb, priv->sample_time);
     pb_u32(pb, priv->frequency);
+    pb_u16(pb, priv->buffer_size);
 }
 
 // ------------------------------------------------------------------------
@@ -61,6 +66,9 @@ error_t UADC_loadIni(Unit *unit, const char *key, const char *value)
     else if (streq(key, "frequency")) {
         priv->frequency = (uint32_t) avr_atoi(value);
     }
+    else if (streq(key, "buffer_size")) {
+        priv->buffer_size = (uint16_t) avr_atoi(value);
+    }
     else {
         return E_BAD_KEY;
     }
@@ -89,5 +97,11 @@ void UADC_writeIni(Unit *unit, IniWriter *iw)
 
     iw_comment(iw, "Sampling frequency (Hz)");
     iw_entry(iw, "frequency", "%d", (int)priv->frequency);
+
+    iw_comment(iw, "Sample buffer size (bytes, 2 per channels per sample)");
+    iw_comment(iw, "- a report is sent when 1/2 of the circular buffer is filled");
+    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);
 }