Feature: Add LilyGo T-Echo Card board variant

.gitignore

@@ -17,3 +17,4 @@ compile_commands.json
 .venv/
 venv/
 platformio.local.ini
+.DS_Store

boards/lilygo_techo_card.json

@@ -0,0 +1,50 @@
+{
+  "build": {
+    "arduino": {
+      "ldscript": "nrf52840_s140_v6.ld"
+    },
+    "core": "nRF5",
+    "cpu": "cortex-m4",
+    "extra_flags": "-DNRF52840_XXAA",
+    "f_cpu": "64000000L",
+    "hwids": [
+      ["0x239A", "0x8029"]
+    ],
+    "usb_product": "T-Echo Card",
+    "mcu": "nrf52840",
+    "variant": "lilygo_techo_card",
+    "variants_dir": "variants_bsp",
+    "bsp": {
+      "name": "adafruit"
+    },
+    "softdevice": {
+      "sd_flags": "-DS140",
+      "sd_name": "s140",
+      "sd_version": "6.1.1",
+      "sd_fwid": "0x00B6"
+    },
+    "bootloader": {
+      "settings_addr": "0xFF000"
+    }
+  },
+  "connectivity": ["bluetooth"],
+  "debug": {
+    "jlink_device": "nRF52840_xxAA",
+    "openocd_target": "nrf52840"
+  },
+  "frameworks": ["arduino"],
+  "name": "LilyGo T-Echo Card (nRF52840, SX1262, 4MB Flash)",
+  "upload": {
+    "maximum_ram_size": 248832,
+    "maximum_size": 815104,
+    "speed": 115200,
+    "protocol": "nrfutil",
+    "protocols": ["nrfutil", "jlink", "cmsis-dap"],
+    "native_usb": true,
+    "use_1200bps_touch": true,
+    "require_upload_port": true,
+    "wait_for_upload_port": true
+  },
+  "url": "https://github.com/Xinyuan-LilyGO/T-Echo-Card",
+  "vendor": "LILYGO"
+}

examples/companion_radio/MyMesh.cpp

@@ -642,6 +642,7 @@ uint8_t MyMesh::onContactRequest(const ContactInfo &contact, uint32_t sender_tim
     if (permissions & TELEM_PERM_BASE) { // only respond if base permission bit is set
       telemetry.reset();
       telemetry.addVoltage(TELEM_CHANNEL_SELF, (float)board.getBattMilliVolts() / 1000.0f);
+      { float t = board.getMCUTemperature(); if (!isnan(t)) telemetry.addTemperature(TELEM_CHANNEL_SELF, t); }
       // query other sensors -- target specific
       sensors.querySensors(permissions, telemetry);
 
@@ -1613,6 +1614,7 @@ void MyMesh::handleCmdFrame(size_t len) {
   } else if (cmd_frame[0] == CMD_SEND_TELEMETRY_REQ && len == 4) {  // 'self' telemetry request
     telemetry.reset();
     telemetry.addVoltage(TELEM_CHANNEL_SELF, (float)board.getBattMilliVolts() / 1000.0f);
+    { float t = board.getMCUTemperature(); if (!isnan(t)) telemetry.addTemperature(TELEM_CHANNEL_SELF, t); }
     // query other sensors -- target specific
     sensors.querySensors(0xFF, telemetry);
 
@@ -2191,3 +2193,12 @@ bool MyMesh::advert() {
     return false;
   }
 }
+
+// To check if there is pending work
+bool MyMesh::hasPendingWork() const {
+  #if defined(WITH_BRIDGE)
+  if (bridge.isRunning()) return true; // bridge needs WiFi radio, can't sleep
+  #endif
+  // If getOutboundTotal() is not available, use: _mgr->getOutboundCount(0xFFFFFFFF) > 0
+  return _mgr->getOutboundTotal() > 0;
+}

examples/companion_radio/MyMesh.h

@@ -174,9 +174,19 @@ class MyMesh : public BaseChatMesh, public DataStoreHost {
       sprintf(interval_str, "%u", _prefs.gps_interval);
       sensors.setSettingValue("gps_interval", interval_str);
     }
+    #if defined(LILYGO_TECHO_CARD)
+    // Power the L76K down at boot if GPS is persisted as off.
+    // Without this, board.begin() drives PIN_GPS_EN HIGH unconditionally
+    // and the chip stays powered until the user manually toggles GPS
+    // twice through the menu.
+    board.enableGPS(_prefs.gps_enabled);
+    #endif
   }
 #endif
 
+  // To check if there is pending work
+  bool hasPendingWork() const;
+
 private:
   void writeOKFrame();
   void writeErrFrame(uint8_t err_code);
@@ -249,4 +259,4 @@ class MyMesh : public BaseChatMesh, public DataStoreHost {
   AdvertPath advert_paths[ADVERT_PATH_TABLE_SIZE]; // circular table
 };
 
-extern MyMesh the_mesh;
+extern MyMesh the_mesh;

examples/companion_radio/main.cpp

@@ -229,4 +229,10 @@ void loop() {
   ui_task.loop();
 #endif
   rtc_clock.tick();
-}
+
+  if (!the_mesh.hasPendingWork()) {
+    #if defined(NRF52_PLATFORM)
+    board.sleep(0); // nrf ignores seconds param, sleeps whenever possible
+    #endif
+  }
+}

examples/companion_radio/ui-new/UITask.cpp

@@ -5,6 +5,9 @@
 #ifdef WIFI_SSID
   #include <WiFi.h>
 #endif
+#if defined(LILYGO_TECHO_CARD)
+  #include "TechoCardHomeScreen.h"
+#endif
 
 #ifndef AUTO_OFF_MILLIS
   #define AUTO_OFF_MILLIS     15000   // 15 seconds
@@ -34,7 +37,7 @@
 class SplashScreen : public UIScreen {
   UITask* _task;
   unsigned long dismiss_after;
-  char _version_info[12];
+  char _version_info[24];
 
 public:
   SplashScreen(UITask* task) : _task(task) {
@@ -52,6 +55,15 @@ class SplashScreen : public UIScreen {
   }
 
   int render(DisplayDriver& display) override {
+#if defined(LILYGO_TECHO_CARD)
+    // Text-only splash for 72×40 OLED -- no room for 128px logo
+    display.setColor(DisplayDriver::GREEN);
+    display.setTextSize(1);
+    display.drawTextCentered(display.width()/2, 2, "MeshCore");
+    display.setColor(DisplayDriver::LIGHT);
+    display.drawTextCentered(display.width()/2, 14, _version_info);
+    display.drawTextCentered(display.width()/2, 26, FIRMWARE_BUILD_DATE);
+#else
     // meshcore logo
     display.setColor(DisplayDriver::BLUE);
     int logoWidth = 128;
@@ -72,6 +84,7 @@ class SplashScreen : public UIScreen {
 
     display.setTextSize(1);
     display.drawTextCentered(display.width()/2, 48, FIRMWARE_BUILD_DATE);
+#endif
 
     return 1000;
   }
@@ -585,8 +598,14 @@ void UITask::begin(DisplayDriver* display, SensorManager* sensors, NodePrefs* no
   _alert_expiry = 0;
 
   splash = new SplashScreen(this);
+#if defined(LILYGO_TECHO_CARD)
+  home = new TechoCardHomeScreen(this, &rtc_clock, node_prefs);
+#else
   home = new HomeScreen(this, &rtc_clock, sensors, node_prefs);
+#endif
+#if !defined(LILYGO_TECHO_CARD)
   msg_preview = new MsgPreviewScreen(this, &rtc_clock);
+#endif
   setCurrScreen(splash);
 }
 
@@ -635,8 +654,10 @@ void UITask::msgRead(int msgcount) {
 void UITask::newMsg(uint8_t path_len, const char* from_name, const char* text, int msgcount) {
   _msgcount = msgcount;
 
+#if !defined(LILYGO_TECHO_CARD)
   ((MsgPreviewScreen *) msg_preview)->addPreview(path_len, from_name, text);
   setCurrScreen(msg_preview);
+#endif
 
   if (_display != NULL) {
     if (!_display->isOn() && !hasConnection()) {
@@ -742,9 +763,49 @@ void UITask::loop() {
   } else if (ev == BUTTON_EVENT_LONG_PRESS) {
     c = handleLongPress(KEY_ENTER);
   } else if (ev == BUTTON_EVENT_DOUBLE_CLICK) {
+    #if defined(LILYGO_TECHO_CARD)
+    // Toggle screen on/off for battery saving
+    if (_display != NULL) {
+      if (_display->isOn()) {
+        _display->turnOff();
+      } else {
+        _display->turnOn();
+        _auto_off = millis() + AUTO_OFF_MILLIS;
+        _next_refresh = 0;
+      }
+    }
+    c = 0; // consume event
+    #else
     c = handleDoubleClick(KEY_PREV);
+    #endif
   } else if (ev == BUTTON_EVENT_TRIPLE_CLICK) {
+    #if defined(LILYGO_TECHO_CARD)
+    toggleBuzzer();
+    c = 0; // consume event
+    #else
     c = handleTripleClick(KEY_SELECT);
+    #endif
+  }
+#endif
+#if defined(PIN_BOOT_BTN)
+  // Second navigation button (C / Boot on T-Echo Card) + torch
+  {
+    static MomentaryButton boot_btn(PIN_BOOT_BTN, LONG_PRESS_MILLIS, true);
+    static bool _boot_btn_ready = false;
+    if (!_boot_btn_ready) { boot_btn.begin(); _boot_btn_ready = true; }
+    static bool torch_on = false;
+    int ev2 = boot_btn.check();
+    if (ev2 == BUTTON_EVENT_CLICK && c == 0) {
+      c = checkDisplayOn(KEY_PREV);
+    } else if (ev2 == BUTTON_EVENT_DOUBLE_CLICK) {
+      torch_on = !torch_on;
+      if (torch_on) {
+        // Single LED only -- driving all three white exceeds RT9080 current budget and reboots
+        board.setStatusLED(0, 0xFFFFFF);
+      } else {
+        board.setStatusLED(0, 0);
+      }
+    }
   }
 #endif
 #if defined(PIN_USER_BTN_ANA)
@@ -905,6 +966,12 @@ void UITask::toggleGPS() {
           _node_prefs->gps_enabled = 1;
           notify(UIEventType::ack);
         }
+        #if defined(LILYGO_TECHO_CARD)
+        // Actually power the L76K down/up at the hardware level.
+        // Without this, toggling GPS off only stops reading position data
+        // while the chip itself stays powered (~25mA draw).
+        board.enableGPS(_node_prefs->gps_enabled);
+        #endif
         the_mesh.savePrefs();
         showAlert(_node_prefs->gps_enabled ? "GPS: Enabled" : "GPS: Disabled", 800);
         _next_refresh = 0;
@@ -928,4 +995,4 @@ void UITask::toggleBuzzer() {
     showAlert(buzzer.isQuiet() ? "Buzzer: OFF" : "Buzzer: ON", 800);
     _next_refresh = 0;  // trigger refresh
   #endif
-}
+}

src/helpers/ui/U8g2Display.h

@@ -0,0 +1,127 @@
+#pragma once
+
+#include "DisplayDriver.h"
+#include <U8g2lib.h>
+#include <Wire.h>
+
+#ifndef DISPLAY_ADDRESS
+  #define DISPLAY_ADDRESS   0x3C
+#endif
+
+#ifndef OLED_WIDTH
+  #define OLED_WIDTH        72
+#endif
+
+#ifndef OLED_HEIGHT
+  #define OLED_HEIGHT       40
+#endif
+
+class U8g2Display : public DisplayDriver {
+  // U8g2 constructor for SSD1306/SSD1315 72×40 panel — handles all
+  // GDDRAM column/page offsets, SETMULTIPLEX, SETDISPLAYOFFSET internally
+  U8G2_SSD1306_72X40_ER_F_HW_I2C _u8g2;
+  bool _isOn;
+  uint8_t _drawColor;
+
+  // Font metrics for current font (cached on setTextSize)
+  uint8_t _fontAscent;
+  uint8_t _fontHeight;
+
+  void applyFont(int sz) {
+    if (sz >= 2) {
+      _u8g2.setFont(u8g2_font_5x7_mr);      // 5×7 — "large" for this display
+    } else {
+      _u8g2.setFont(u8g2_font_5x7_mr);
+    }
+    _fontAscent = _u8g2.getAscent();
+    _fontHeight = _u8g2.getAscent() - _u8g2.getDescent();
+  }
+
+public:
+  U8g2Display() : DisplayDriver(OLED_WIDTH, OLED_HEIGHT),
+      _u8g2(U8G2_R0, /* reset=*/ U8X8_PIN_NONE),
+      _isOn(false), _drawColor(1), _fontAscent(5), _fontHeight(6) {}
+
+  bool begin() {
+    // Wire must already be initialised by board.begin() before this is called
+    bool ok = _u8g2.begin();
+    if (ok) {
+      _u8g2.setI2CAddress(DISPLAY_ADDRESS * 2);  // U8g2 uses 8-bit address
+      _u8g2.setFontPosTop();     // y coordinate = top of text, not baseline
+      _u8g2.setFontMode(1);      // transparent background
+      applyFont(1);              // default to compact font
+      _isOn = true;
+    }
+    return ok;
+  }
+
+  bool isOn() override { return _isOn; }
+
+  void turnOn() override {
+    _u8g2.setPowerSave(0);
+    _isOn = true;
+  }
+
+  void turnOff() override {
+    _u8g2.setPowerSave(1);
+    _isOn = false;
+  }
+
+  void clear() override {
+    _u8g2.clearBuffer();
+    _u8g2.sendBuffer();
+  }
+
+  void startFrame(Color bkg = DARK) override {
+    _u8g2.clearBuffer();
+    _drawColor = 1;
+    _u8g2.setDrawColor(1);
+    applyFont(1);
+  }
+
+  void setTextSize(int sz) override {
+    applyFont(sz);
+  }
+
+  void setColor(Color c) override {
+    _drawColor = (c != DARK) ? 1 : 0;
+    _u8g2.setDrawColor(_drawColor);
+  }
+
+  void setCursor(int x, int y) override {
+    _cursorX = x;
+    _cursorY = y;
+  }
+
+  void print(const char* str) override {
+    _u8g2.setDrawColor(_drawColor);
+    _u8g2.drawStr(_cursorX, _cursorY, str);
+  }
+
+  void fillRect(int x, int y, int w, int h) override {
+    _u8g2.setDrawColor(_drawColor);
+    _u8g2.drawBox(x, y, w, h);
+  }
+
+  void drawRect(int x, int y, int w, int h) override {
+    _u8g2.setDrawColor(_drawColor);
+    _u8g2.drawFrame(x, y, w, h);
+  }
+
+  void drawXbm(int x, int y, const uint8_t* bits, int w, int h) override {
+    _u8g2.setDrawColor(1);
+    _u8g2.drawXBM(x, y, w, h, bits);
+  }
+
+  uint16_t getTextWidth(const char* str) override {
+    return _u8g2.getStrWidth(str);
+  }
+
+  void endFrame() override {
+    _u8g2.sendBuffer();
+  }
+
+private:
+  int _cursorX = 0;
+  int _cursorY = 0;
+};