add qrcode service

nspanel_esphome.yaml

@@ -238,6 +238,16 @@ api:
         - rtttl.play:
             rtttl: !lambda 'return song_str;'    
 
+    # Service to show a QR code on the display (ex. for WiFi password)
+    - service: qr_code
+      variables:
+        qrdata: string
+      then:
+        - wait_until:
+              switch.is_on: nextion_init
+        - lambda: |-
+            id(disp1).set_component_text_printf("qrcode.qrcode_value", "%s", qrdata.c_str());
+
     #### Service to send thermostat cycle state ####
     - service: send_thermostat_cycle_state
       variables: