Use less memory (#644)

a) closeFile() now does SD.end() to release memory
after running a file from SD.
b) Several task stacks are smaller
c) All tasks now check their free space if DEBUG_REPORT_STACK_FREE
is defined.  platformio.ini has a commented-out line that can be
uncommented to turn that on.
d) Similarly, platformio.ini can turn on DEBUG_REPORT_HEAP_SIZE
e) Fixed a small leak that occurred when listing local files.

With these changes, the heap size tends to hover around 53K, dropping
to about 37K when running a file from SD.

Grbl_Esp32/src/I2SOut.cpp

@@ -42,6 +42,14 @@
  */
 #include "Config.h"
 
+// This block of #includes is necessary for Report.h
+#include "Error.h"
+#include "WebUI/Authentication.h"
+#include "WebUI/ESPResponse.h"
+#include "Probe.h"
+#include "System.h"
+#include "Report.h"
+
 #include <FreeRTOS.h>
 #include <driver/periph_ctrl.h>
 #include <rom/lldesc.h>
@@ -516,6 +524,9 @@ static void IRAM_ATTR i2sOutTask(void* parameter) {
             o_dma.rw_pos = 0;                   // If someone calls i2s_out_push_sample, make sure there is no buffer overflow
         }
         I2S_OUT_PULSER_EXIT_CRITICAL();  // Unlock pulser status
+
+        static UBaseType_t uxHighWaterMark = 0;
+        reportTaskStackSize(uxHighWaterMark);
     }
 }
 #endif
@@ -907,7 +918,7 @@ int IRAM_ATTR i2s_out_init(i2s_out_init_t& init_param) {
     // Create the task that will feed the buffer
     xTaskCreatePinnedToCore(i2sOutTask,
                             "I2SOutTask",
-                            1024 * 10,
+                            4096,
                             NULL,
                             1,
                             nullptr,

Grbl_Esp32/src/Limits.cpp

@@ -330,11 +330,8 @@ void limits_init() {
                 }
 
                 if (limit_sw_queue == NULL) {
-                    grbl_msg_sendf(CLIENT_SERIAL,
+                    grbl_msg_sendf(
-                                   MsgLevel::Info,
+                        CLIENT_SERIAL, MsgLevel::Info, "%s limit switch on pin %s", reportAxisNameMsg(axis, gang_index), pinName(pin).c_str());
-                                   "%s limit switch on pin %s",
-                                   reportAxisNameMsg(axis, gang_index),
-                                   pinName(pin).c_str());
                 }
             }
         }
@@ -427,6 +424,8 @@ void limitCheckTask(void* pvParameters) {
             mc_reset();                                // Initiate system kill.
             sys_rt_exec_alarm = ExecAlarm::HardLimit;  // Indicate hard limit critical event
         }
+        static UBaseType_t uxHighWaterMark = 0;
+        reportTaskStackSize(uxHighWaterMark);
     }
 }
 

Grbl_Esp32/src/Motors/Servo.cpp

@@ -60,18 +60,14 @@ namespace Motors {
         xLastWakeTime = xTaskGetTickCount();  // Initialise the xLastWakeTime variable with the current time.
         vTaskDelay(2000);                     // initial delay
         while (true) {                        // don't ever return from this or the task dies
-
-            // static UBaseType_t uxHighWaterMark = 0;
-            // if (uxHighWaterMark != uxTaskGetStackHighWaterMark(NULL)) {
-            //     uxHighWaterMark = uxTaskGetStackHighWaterMark(NULL);
-            //     grbl_msg_sendf(CLIENT_SERIAL, MsgLevel::Info, "Servo Task Min Stack Space: %d", uxHighWaterMark);
-            // }
-
             for (Servo* p = List; p; p = p->link) {
                 p->update();
             }
 
             vTaskDelayUntil(&xLastWakeTime, xUpdate);
+
+            static UBaseType_t uxHighWaterMark = 0;
+            reportTaskStackSize(uxHighWaterMark);
         }
     }
 

Grbl_Esp32/src/Motors/TrinamicDriver.cpp

@@ -360,13 +360,10 @@ namespace Motors {
                 }  // sys.state
             }      // if mask
 
-            // static UBaseType_t uxHighWaterMark = 0;
-            // if (uxHighWaterMark != uxTaskGetStackHighWaterMark(NULL)) {
-            //     uxHighWaterMark = uxTaskGetStackHighWaterMark(NULL);
-            //     grbl_msg_sendf(CLIENT_SERIAL, MsgLevel::Info, "SG Task Stack Space: %d", uxHighWaterMark);
-            // }
-
             vTaskDelayUntil(&xLastWakeTime, xreadSg);
+
+            static UBaseType_t uxHighWaterMark = 0;
+            reportTaskStackSize(uxHighWaterMark);
         }
     }
 }

Grbl_Esp32/src/Report.cpp

@@ -938,3 +938,13 @@ char* reportAxisNameMsg(uint8_t axis) {
     sprintf(name, "%c  Axis", report_get_axis_letter(axis));
     return name;
 }
+
+void reportTaskStackSize(UBaseType_t& saved) {
+#ifdef DEBUG_REPORT_STACK_FREE
+    UBaseType_t        newHighWater    = uxTaskGetStackHighWaterMark(NULL);
+    if (newHighWater != saved) {
+        saved = newHighWater;
+        grbl_msg_sendf(CLIENT_SERIAL, MsgLevel::Info, "%s Min Stack Space: %d", pcTaskGetTaskName(NULL), saved);
+    }
+#endif
+}

Grbl_Esp32/src/Report.h

@@ -127,3 +127,5 @@ char report_get_axis_letter(uint8_t axis);
 char* reportAxisLimitsMsg(uint8_t axis);
 char* reportAxisNameMsg(uint8_t axis);
 char* reportAxisNameMsg(uint8_t axis, uint8_t dual_axis);
+
+void  reportTaskStackSize(UBaseType_t& saved);

Grbl_Esp32/src/SDCard.cpp

@@ -81,6 +81,7 @@ boolean closeFile() {
     SD_ready_next          = false;
     sd_current_line_number = 0;
     myFile.close();
+    SD.end();
     return true;
 }
 
@@ -147,7 +148,7 @@ uint8_t get_sd_state(bool refresh) {
     sd_state = SDCARD_NOT_PRESENT;
     //using default value for speed ? should be parameter
     //refresh content if card was removed
-    if (SD.begin((GRBL_SPI_SS == -1) ? SS : GRBL_SPI_SS, SPI, GRBL_SPI_FREQ)) {
+    if (SD.begin((GRBL_SPI_SS == -1) ? SS : GRBL_SPI_SS, SPI, GRBL_SPI_FREQ, "/sd", 2)) {
         if (SD.cardSize() > 0) {
             sd_state = SDCARD_IDLE;
         }

Grbl_Esp32/src/Serial.cpp

@@ -68,7 +68,27 @@ uint8_t serial_get_rx_buffer_available(uint8_t client) {
     return client_buffer[client].availableforwrite();
 }
 
+void heapCheckTask(void* pvParameters) {
+    static uint32_t heapSize = 0;
+    while (true) {
+        uint32_t newHeapSize = xPortGetFreeHeapSize();
+        if (newHeapSize != heapSize) {
+            heapSize = newHeapSize;
+            grbl_msg_sendf(CLIENT_SERIAL, MsgLevel::Info, "heap %d", heapSize);
+        }
+        vTaskDelay(3000 / portTICK_RATE_MS);  // Yield to other tasks
+
+        static UBaseType_t uxHighWaterMark = 0;
+        reportTaskStackSize(uxHighWaterMark);
+    }
+}
+
 void serial_init() {
+#ifdef DEBUG_REPORT_HEAP_SIZE
+    // For a 2000-word stack, uxTaskGetStackHighWaterMark reports 288 words available
+    xTaskCreatePinnedToCore(heapCheckTask, "heapTask", 2000, NULL, 1, NULL, 1);
+#endif
+
     Serial.begin(BAUD_RATE);
     Serial.setRxBufferSize(256);
     // reset all buffers
@@ -76,9 +96,11 @@ void serial_init() {
     grbl_send(CLIENT_SERIAL, "\r\n");  // create some white space after ESP32 boot info
     serialCheckTaskHandle = 0;
     // create a task to check for incoming data
+    // For a 4096-word stack, uxTaskGetStackHighWaterMark reports 244 words available
+    // after WebUI attaches.
     xTaskCreatePinnedToCore(serialCheckTask,    // task
                             "serialCheckTask",  // name for task
-                            8192,               // size of task stack
+                            4096,               // size of task stack
                             NULL,               // parameters
                             1,                  // priority
                             &serialCheckTaskHandle,
@@ -91,6 +113,7 @@ void serial_init() {
 void serialCheckTask(void* pvParameters) {
     uint8_t            data            = 0;
     uint8_t            client          = CLIENT_ALL;  // who sent the data
+    static UBaseType_t uxHighWaterMark = 0;
     while (true) {  // run continuously
         while (any_client_has_data()) {
             if (Serial.available()) {
@@ -149,6 +172,9 @@ void serialCheckTask(void* pvParameters) {
         WebUI::Serial2Socket.handle_flush();
 #endif
         vTaskDelay(1 / portTICK_RATE_MS);  // Yield to other tasks
+
+        static UBaseType_t uxHighWaterMark = 0;
+        reportTaskStackSize(uxHighWaterMark);
     }  // while(true)
 }
 

Grbl_Esp32/src/Spindles/VFDSpindle.cpp

@@ -185,6 +185,9 @@ namespace Spindles {
                     // Wait a bit before we retry. Set the delay to poll-rate. Not sure
                     // if we should use a different value...
                     vTaskDelay(VFD_RS485_POLL_RATE);
+
+                    static UBaseType_t uxHighWaterMark = 0;
+                    reportTaskStackSize(uxHighWaterMark);
                 }
             }
 

Grbl_Esp32/src/System.cpp

@@ -123,6 +123,9 @@ void controlCheckTask(void* pvParameters) {
             system_exec_control_pin(pins);
         }
         debouncing = false;
+
+        static UBaseType_t uxHighWaterMark = 0;
+        reportTaskStackSize(uxHighWaterMark);
     }
 }
 #endif

Grbl_Esp32/src/System.h

@@ -20,8 +20,6 @@
   along with Grbl.  If not, see <http://www.gnu.org/licenses/>.
 */
 
-#include "Grbl.h"
-
 // System states. The state variable primarily tracks the individual functions
 // of Grbl to manage each without overlapping. It is also used as a messaging flag for
 // critical events.

Grbl_Esp32/src/WebUI/WebSettings.cpp

@@ -600,9 +600,9 @@ namespace WebUI {
 
 #ifdef ENABLE_WIFI
     static Error listAPs(char* parameter, AuthenticationLevel auth_level) {  // ESP410
-        JSONencoder* j = new JSONencoder(espresponse->client() != CLIENT_WEBUI);
+        JSONencoder j(espresponse->client() != CLIENT_WEBUI);
-        j->begin();
+        j.begin();
-        j->begin_array("AP_LIST");
+        j.begin_array("AP_LIST");
         // An initial async scanNetworks was issued at startup, so there
         // is a good chance that scan information is already available.
         int n = WiFi.scanComplete();
@@ -614,12 +614,12 @@ namespace WebUI {
                 break;
             default:
                 for (int i = 0; i < n; ++i) {
-                    j->begin_object();
+                    j.begin_object();
-                    j->member("SSID", WiFi.SSID(i));
+                    j.member("SSID", WiFi.SSID(i));
-                    j->member("SIGNAL", wifi_config.getSignal(WiFi.RSSI(i)));
+                    j.member("SIGNAL", wifi_config.getSignal(WiFi.RSSI(i)));
-                    j->member("IS_PROTECTED", WiFi.encryptionType(i) != WIFI_AUTH_OPEN);
+                    j.member("IS_PROTECTED", WiFi.encryptionType(i) != WIFI_AUTH_OPEN);
                     //            j->member("IS_PROTECTED", WiFi.encryptionType(i) == WIFI_AUTH_OPEN ? "0" : "1");
-                    j->end_object();
+                    j.end_object();
                 }
                 WiFi.scanDelete();
                 // Restart the scan in async mode so new data will be available
@@ -630,9 +630,8 @@ namespace WebUI {
                 }
                 break;
         }
-        j->end_array();
+        j.end_array();
-        webPrint(j->end());
+        webPrint(j.end());
-        delete j;
         if (espresponse->client() != CLIENT_WEBUI) {
             espresponse->println("");
         }
@@ -657,17 +656,16 @@ namespace WebUI {
     }
 
     static Error listSettings(char* parameter, AuthenticationLevel auth_level) {  // ESP400
-        JSONencoder* j = new JSONencoder(espresponse->client() != CLIENT_WEBUI);
+        JSONencoder j(espresponse->client() != CLIENT_WEBUI);
-        j->begin();
+        j.begin();
-        j->begin_array("EEPROM");
+        j.begin_array("EEPROM");
         for (Setting* js = Setting::List; js; js = js->next()) {
             if (js->getType() == WEBSET) {
-                js->addWebui(j);
+                js->addWebui(&j);
             }
         }
-        j->end_array();
+        j.end_array();
-        webPrint(j->end());
+        webPrint(j.end());
-        delete j;
         return Error::Ok;
     }
 
@@ -833,15 +831,15 @@ namespace WebUI {
     }
 
     static Error listLocalFilesJSON(char* parameter, AuthenticationLevel auth_level) {  // No ESP command
-        JSONencoder* j = new JSONencoder(espresponse->client() != CLIENT_WEBUI);
+        JSONencoder j(espresponse->client() != CLIENT_WEBUI);
-        j->begin();
+        j.begin();
-        j->begin_array("files");
+        j.begin_array("files");
-        listDirJSON(SPIFFS, "/", 4, j);
+        listDirJSON(SPIFFS, "/", 4, &j);
-        j->end_array();
+        j.end_array();
-        j->member("total", SPIFFS.totalBytes());
+        j.member("total", SPIFFS.totalBytes());
-        j->member("used", SPIFFS.usedBytes());
+        j.member("used", SPIFFS.usedBytes());
-        j->member("occupation", String(100 * SPIFFS.usedBytes() / SPIFFS.totalBytes()));
+        j.member("occupation", String(100 * SPIFFS.usedBytes() / SPIFFS.totalBytes()));
-        webPrint(j->end());
+        webPrint(j.end());
         if (espresponse->client() != CLIENT_WEBUI) {
             webPrintln("");
         }

platformio.ini

@@ -28,6 +28,8 @@ build_flags =
 	-DCORE_DEBUG_LEVEL=0
 	-Wno-unused-variable
 	-Wno-unused-function
+        ;-DDEBUG_REPORT_HEAP_SIZE
+        ;-DDEBUG_REPORT_STACK_FREE
 
 [env]
 lib_deps =