feature: transmit path works (queue-less)

Author: uhi22

README.md

@@ -71,7 +71,7 @@ So we end-up with the following features for the moment:
 
 The states and transitions of the ESP32S3 CAN driver are described here: https://docs.espressif.com/projects/esp-idf/en/latest/esp32s3/api-reference/peripherals/twai.html
 
-### How did the CAN reception work (in the old world with espressif TWAI driver?
+### How did the CAN reception work (in the old world with espressif TWAI driver)?
 
 - During startup, the task task_LowLevelRX is started.
 - The task_LowLevelRX suspends in twai_receive().
@@ -96,6 +96,16 @@ canBuses[i]->watchFor() --> setRXFilter()
 CAN_COMMON::attachCANInterrupt() --> CAN0.setCallback() --> 
 ...tbd...
 
+### Where is the espressif TWAI driver stored?
+
+Source code in the espressif IDE:
+- C:\esp-idf-v4.4.4\components\driver\twai.c
+
+Header and lib in the arduino IDE:
+- C:\Users\uwemi\AppData\Local\Arduino15\packages\esp32\hardware\esp32\2.0.13\tools\sdk\esp32s3\include\driver\include\driver\twai.h
+- C:\Users\uwemi\AppData\Local\Arduino15\packages\esp32\hardware\esp32\2.0.13\tools\sdk\esp32s3\lib\libdriver.a
+
+
 ### Is useBinarySerialComm true?
 
 Yes, the SavvyCAN sends 0xE7 as first two bytes. This turns-on the binary mode.

esp32_can_builtin_local.cpp

@@ -39,6 +39,13 @@ twai_filter_config_t twai_filters_cfg = TWAI_FILTER_CONFIG_ACCEPT_ALL();
 #define TWAI_ISR_ATTR
 #define TWAI_MALLOC_CAPS    MALLOC_CAP_DEFAULT
 #endif  //CONFIG_TWAI_ISR_IN_IRAM
+
+#define TWAI_CHECK(cond, ret_val) ({                                        \
+            if (!(cond)) {                                                  \
+                return (ret_val);                                           \
+            }                                                               \
+})
+
 intr_handle_t experimental_isr_handle;
 static twai_hal_context_t twai_context;
 volatile uint32_t expCounterIsr;
@@ -400,19 +407,39 @@ void ESP32CAN::disable()
     //twai_driver_uninstall();
 }
 
+esp_err_t my_twai_transmit(const twai_message_t *message) {
+    /* based on: C:\esp-idf-v4.4.4\components\driver\twai.c,
+    but without queue. This means: If the application sends
+    faster than the CAN is able to handle, the message will
+    be lost. A queue would not improve this situation long term. */
+    
+    /* Check arguments */
+    TWAI_CHECK(message != NULL, ESP_ERR_INVALID_ARG);
+    TWAI_CHECK((message->data_length_code <= TWAI_FRAME_MAX_DLC) || message->dlc_non_comp, ESP_ERR_INVALID_ARG);
+    
+    /* Format frame */
+    esp_err_t ret = ESP_FAIL;
+    twai_hal_frame_t tx_frame;
+    twai_hal_format_frame(message, &tx_frame);
+    /* try to send the frame immediately */
+    twai_hal_set_tx_buffer_and_transmit(&twai_context, &tx_frame);
+    ret = ESP_OK;
+    return ret;
+}
+
 bool ESP32CAN::sendFrame(CAN_FRAME& txFrame)
 {
     twai_message_t __TX_frame;
+    int returnCode;
 
     __TX_frame.identifier = txFrame.id;
     __TX_frame.data_length_code = txFrame.length;
     __TX_frame.rtr = txFrame.rtr;
     __TX_frame.extd = txFrame.extended;
     for (int i = 0; i < 8; i++) __TX_frame.data[i] = txFrame.data.byte[i];
 
-    //don't wait long if the queue was full. The end user code shouldn't be sending faster
-    //than the buffer can empty. Set a bigger TX buffer or delay sending if this is a problem.
-    switch (twai_transmit(&__TX_frame, pdMS_TO_TICKS(4)))
+    returnCode = my_twai_transmit(&__TX_frame);
+    switch (returnCode)
     {
     case ESP_OK:
         if (debuggingMode) Serial.write('<');
@@ -424,7 +451,10 @@ bool ESP32CAN::sendFrame(CAN_FRAME& txFrame)
     case ESP_FAIL:
     case ESP_ERR_INVALID_STATE:
     case ESP_ERR_NOT_SUPPORTED:
-        if (debuggingMode) Serial.write('!');
+        if (debuggingMode) {
+            Serial.write('!');
+            Serial.print(returnCode);
+        }
         break;
     }
 

savvycan_signalview_wifican_and_foccci.sdf

@@ -0,0 +1,11 @@
+SV1,1000,wificanStatistics1,wificanAliveCounter
+SV1,1000,wificanStatistics1,wificanTotalRxMessages
+SV1,1001,wificanStatistics2,wificanLostRxFrames
+SV1,567,FOCCCI01,foccci_uptime_s
+SV1,567,FOCCCI01,foccciCheckpoint
+SV1,568,foccciFast01,EVSEPresentVoltage
+SV1,568,foccciFast01,uCcsInlet_V
+SV1,569,foccciTemperatures01,TempCPU
+SV1,569,foccciTemperatures01,Temp1
+SV1,569,foccciTemperatures01,Temp2
+SV1,569,foccciTemperatures01,Temp3