Allow scripting to override notify displays

libraries/AP_Notify/AP_Notify.cpp

@@ -382,6 +382,16 @@ void AP_Notify::handle_rgb(uint8_t r, uint8_t g, uint8_t b, uint8_t rate_hz)
     }
 }
 
+// handle display override from scripting
+void AP_Notify::handle_scr_disp(uint8_t r, const char *str)
+{
+    for (uint8_t i = 0; i < _num_devices; i++) {
+        if (_devices[i] != nullptr) {
+            _devices[i]->scr_disp_overide(r, str);
+        }
+    }
+}
+
 // handle a PLAY_TUNE message
 void AP_Notify::handle_play_tune(const mavlink_message_t &msg)
 {

libraries/AP_Notify/AP_Notify.h

@@ -147,6 +147,9 @@ class AP_Notify
     // handle a PLAY_TUNE message
     static void handle_play_tune(const mavlink_message_t &msg);
 
+    // handle display override from scripting
+    static void handle_scr_disp(uint8_t r, const char *str);
+
     // play a tune string
     static void play_tune(const char *tune);
 

libraries/AP_Notify/Display.cpp

@@ -377,6 +377,17 @@ void Display::update()
     }
     timer = 0;
 
+    // If we have received an override from scripting recently allow update
+    if (AP_HAL::millis() - _last_scr_override <= _script_timeout_ms) {
+        if (_screenpage != 3) {
+            _driver->clear_screen();
+            _screenpage = 3;
+        }
+        update_scr_screen();
+        _driver->hw_update();
+        return;
+    }
+
     if (AP_Notify::flags.armed) {
         if (_screenpage != 1) {
             _driver->clear_screen();
@@ -582,3 +593,18 @@ void Display::update_text(uint8_t r)
 
     draw_text(COLUMN(0), ROW(0), msg);
  }
+
+// Allow scripting to override text lines on the display
+void Display::scr_disp_overide(uint8_t r, const char *str) {
+    // Prevent chars being left from previous message by clearing with spaces first
+    memset(_scr_msg[r], ' ', DISPLAY_MESSAGE_SIZE-1); // leave null termination
+    strncpy(_scr_msg[r], str, strlen(str));
+
+    _last_scr_override = AP_HAL::millis();
+}
+
+void Display::update_scr_screen() {
+    for (uint8_t i = 0; i < 6; i++) {
+        draw_text(COLUMN(0), ROW(i), _scr_msg[i]);
+    }
+}

libraries/AP_Notify/Display.h

@@ -16,6 +16,9 @@ class Display: public NotifyDevice {
     bool init(void) override;
     void update() override;
 
+    // Allows scripting to override the display message
+    void scr_disp_overide(uint8_t r, const char *str) override;
+
 private:
     void draw_char(uint16_t x, uint16_t y, const char c);
     void draw_text(uint16_t x, uint16_t y, const char *c);
@@ -36,6 +39,14 @@ class Display: public NotifyDevice {
     uint8_t _movedelay; // ticker delay before shifting after new message displayed
     uint8_t _screenpage;
 
+    void update_scr_screen(void);
+
+    // stop scripting override if we have not recieved anything for 5 sec
+    static const uint16_t _script_timeout_ms = 5000;
+
+    uint32_t _last_scr_override;
+    char _scr_msg[6][DISPLAY_MESSAGE_SIZE] = {};
+
     // stop showing text in display after this many millis:
     const uint16_t _send_text_valid_millis = 20000;
 };

libraries/AP_Notify/NotifyDevice.h

@@ -27,6 +27,9 @@ class NotifyDevice {
     // give RGB and flash rate, used with scripting
     virtual void rgb_control(uint8_t r, uint8_t g, uint8_t b, uint8_t rate_hz) {}
 
+    // Allows scripting to override the display message
+    virtual void scr_disp_overide(uint8_t r, const char *str) {}
+
     // this pointer is used to read the parameters relative to devices
     const AP_Notify *pNotify;
 };

libraries/AP_Scripting/examples/use_notify_display.lua

@@ -0,0 +1,37 @@
+-- This is a simple script example that shows how to use the notify display override.
+-- In this example battery voltage and percent remaining is retrieved and displayed 
+-- on screen to act as a handy onboard display for checking the batteries.
+
+local function update()
+
+    local voltage = 0
+    local remaining = 0
+    local healthy = battery:healthy(0)
+
+    -- Update display
+    -- First argument is line number.  There are up to 6 lines available.  0 based numbering is used
+    -- Second argument is the string to be displayed.  Up to 19 characters can be displayed on each line
+    notify:handle_scr_disp(0," --- ArduPilot --- ")
+
+    if (healthy) then
+        -- Get voltage and display it on line 3
+        voltage = battery:voltage(0)
+        notify:handle_scr_disp(2, string.format("  Voltage: %.2f V", voltage))
+
+        -- Get pack remaining and display it on line 5
+        remaining = battery:capacity_remaining_pct(0)
+        notify:handle_scr_disp(4, string.format("Remaining: %.2f %%", remaining))
+
+    else
+        -- voltage monitor is unhealthy 
+        notify:handle_scr_disp(3, "  Battery Monitor  ")
+        notify:handle_scr_disp(4, "     Unhealthy     ")
+    end
+
+    -- Display is updated at 2 Hz so no point in calling any faster than that
+    return update, 500
+
+end
+
+-- Wait for 5 sec before starting script
+return update, 5000

libraries/AP_Scripting/generator/description/bindings.desc

@@ -127,6 +127,7 @@ include AP_Notify/AP_Notify.h
 singleton AP_Notify alias notify
 singleton AP_Notify method play_tune void string
 singleton AP_Notify method handle_rgb void uint8_t 0 UINT8_MAX uint8_t 0 UINT8_MAX uint8_t 0 UINT8_MAX uint8_t 0 UINT8_MAX
+singleton AP_Notify method handle_scr_disp void uint8_t 0 5 string
 
 include AP_Proximity/AP_Proximity.h