start serial console on command, fix exit

lib/uuid-console/src/shell.cpp

@@ -85,11 +85,7 @@ void Shell::stop() {
 
         blocking_data->stop_ = true;
     } else {
-#if defined(EMSESP_STANDALONE)
         if (running()) {
-#else
-        if (running() && !has_flags(CommandFlags::LOCAL)) { // do not close local shell
-#endif
             stopped_ = true;
             stopped();
         }

src/emsesp.cpp

@@ -1341,7 +1341,7 @@ bool EMSESP::add_device(const uint8_t device_id, const uint8_t product_id, const
     fetch_device_values(device_id); // go and fetch its device entity data
 
     // Print to LOG showing we've added a new device
-    LOG_INFO("Dectected EMS device: %s (0x%02X)", EMSdevice::device_type_2_device_name(device_type), device_id);
+    LOG_INFO("Detected EMS device: %s (0x%02X)", EMSdevice::device_type_2_device_name(device_type), device_id);
 
     // register the MQTT subscribe topic for this device
     // except for connect, controller and gateway
@@ -1542,20 +1542,12 @@ void EMSESP::start() {
     system_.PSram(ESP.getPsramSize());
 #endif
 
-// don't need shell if running unit tests
-#ifndef EMSESP_UNITY
-    // Serial console's shell
     serial_console_.begin(SERIAL_CONSOLE_BAUD_RATE);
-    shell_ = std::make_shared<EMSESPConsole>(*this, serial_console_, true);
-    shell_->maximum_log_messages(100);
-    shell_->start();
-#if defined(EMSESP_DEBUG)
-    shell_->log_level(uuid::log::Level::DEBUG);
-#else
-    shell_->log_level(uuid::log::Level::TRACE);
-#endif
+
+// always start a serial console if we're running standalone, except if we're running unit tests
 #if defined(EMSESP_STANDALONE)
-    shell_->add_flags(CommandFlags::ADMIN); // always start in su/admin mode when running tests
+#ifndef EMSESP_UNITY
+    start_serial_console();
 #endif
 #endif
 
@@ -1580,9 +1572,11 @@ void EMSESP::start() {
     bool factory_settings = false;
 #endif
 
-    webLogService.begin(); // start web log service. now we can start capturing logs to the web log
+    // start web log service. now we can start capturing logs to the web log
+    webLogService.begin();
 
-    esp8266React.begin(); // loads core system services settings (network, mqtt, ap, ntp etc)
+    // loads core system services settings (network, mqtt, ap, ntp etc)
+    esp8266React.begin();
 
 #ifndef EMSESP_STANDALONE
     LOG_INFO("Booting EMS-ESP version %s from %s partition", EMSESP_APP_VERSION, esp_ota_get_running_partition()->label); // welcome message
@@ -1654,11 +1648,11 @@ void EMSESP::start() {
 
 // main loop calling all services
 void EMSESP::loop() {
-    esp8266React.loop();              // web services
-    system_.loop();                   // does LED and checks system health, and syslog service
-    static bool upload_status = true; // ready for any OTA uploads
+    esp8266React.loop(); // web services
+    system_.loop();      // does LED and checks system health, and syslog service
 
     // if we're doing an OTA upload, skip everything except from console refresh
+    static bool upload_status = true; // ready for any OTA uploads
     if (!system_.upload_isrunning()) {
         // service loops
         webLogService.loop();       // log in Web UI
@@ -1689,13 +1683,54 @@ void EMSESP::loop() {
     if (system_.telnet_enabled()) {
         telnet_.loop();
     }
-#else
-    if (!shell_->running()) {
-        ::exit(0);
-    }
 #endif
 
     Shell::loop_all();
+
+    static bool show_prompt = true;
+
+    // user has to ctrl-c to create a serial console stream, exit command will close it
+    // this is to save around 2kb of heap memory
+    if (shell_) {
+        if (!shell_->running()) {
+            shell_.reset();
+#ifdef EMSESP_STANDALONE
+            ::exit(0); // kill session
+#endif
+            shell_prompt();
+        }
+    } else {
+        if (show_prompt) {
+            shell_prompt();
+            show_prompt = false; // only show it once
+        }
+        int c = serial_console_.read();
+        if (c != -1) {
+            show_prompt = true;
+        }
+        if (c == '\x03' || c == '\x0C') {
+            start_serial_console();
+        }
+    }
+}
+
+void EMSESP::start_serial_console() {
+    shell_ = std::make_shared<EMSESPConsole>(*this, serial_console_, true);
+    shell_->maximum_log_messages(100);
+    shell_->add_flags(CommandFlags::ADMIN); // always start in su/admin mode when running tests
+    shell_->start();
+#if defined(EMSESP_DEBUG)
+    shell_->log_level(uuid::log::Level::DEBUG);
+#else
+    shell_->log_level(uuid::log::Level::TRACE);
+#endif
+}
+
+void EMSESP::shell_prompt() {
+#ifndef EMSESP_STANDALONE
+    serial_console_.println();
+    serial_console_.println("Press ^C to activate this serial console");
+#endif
 }
 
 } // namespace emsesp

src/emsesp.h

@@ -252,6 +252,9 @@ class EMSESP {
     static void        publish_response(std::shared_ptr<const Telegram> telegram);
     static void        publish_all_loop();
 
+    void shell_prompt();
+    void start_serial_console();
+
     static constexpr uint32_t EMS_FETCH_FREQUENCY = 60000; // check every minute
     static constexpr uint8_t  EMS_WAIT_KM_TIMEOUT = 60;    // wait one minute