try developing a 4k version

node.lua

@@ -5,37 +5,64 @@ local json = require "json"
 local serial = sys.get_env "SERIAL"
 local location = ""
 local description = "<please wait>"
+local upper_text = ""
+local lower_text = ""
+local size_multiplier = 1
+local card = nil
 
 util.data_mapper{
     ["device_info"] = function(info)
         info = json.decode(info)
         location = info.location
         description = info.description
+
+        if location ~= nil and location ~= '' then
+            upper_text = description .. " (" .. serial .. ")"
+            lower_text = location
+        else
+            upper_text = description
+            lower_text = serial
+        end
     end
 }
 
 gl.setup(NATIVE_WIDTH, NATIVE_HEIGHT)
 
-card = resource.load_image("testcard.png")
+if NATIVE_WIDTH > 2000 then
+    card = resource.load_image("testcard_3840.png")
+    size_multiplier = 2
+else
+    card = resource.load_image("testcard_1920.png")
+end
+
 font = resource.load_font("vera.ttf")
 
 function node.render()
+    local render_width = 1920
+    local render_height = 1080
+    local upper_text_pos = 631
+    local lower_text_pos = 679
+    local upper_text_size = 40
+    local lower_text_size = 20
+
     gl.clear(0,0,0,1)
 
-    card:draw(0, 0, 1920, 1080)
+    card:draw(0, 0, 1920*size_multiplier, 1080*size_multiplier)
 
-    -- upper: 623
-    -- lower: 707
+    upper_width = font:width(upper_text, 40*size_multiplier)
+    lower_width = font:width(lower_text, 20*size_multiplier)
 
-    upper_text = description .. " (" .. serial .. ")"
-    upper_width = font:width(upper_text, 40)
+    font:write(
+        (render_width*size_multiplier/2)-(upper_width/2),
+        upper_text_pos*size_multiplier,
+        upper_text,
+        40*size_multiplier,
+        1,1,1,1)
 
-    if location ~= nil and location ~= '' then
-        font:write(960-(upper_width/2), 631, upper_text, 40, 1,1,1,1)
-
-        lower_width = font:width(location, 20)
-        font:write(960-(lower_width/2), 679, location, 20, 1,1,1,1)
-    else
-        font:write(960-(upper_width/2), 645, upper_text, 40, 1,1,1,1)
-    end
+    font:write(
+        (render_width*size_multiplier/2)-(lower_width/2),
+        lower_text_pos*size_multiplier,
+        lower_text,
+        20*size_multiplier,
+        1,1,1,1)
 end