P1 Out could be used too (thanks to Marcel v E)

p1-dongle-pro-h2o-v2.yaml

@@ -2,7 +2,7 @@ substitutions:
   device_name: p1-dongle-pro-h2o
   device_description: "P1 Dongle Pro + H2O v2"
   friendly_name: P1 Dongle Pro H2O
-  prj_version: "2024.6.1"
+  prj_version: "2024.7.1"
 
 esphome:
   name: ${device_name}
@@ -53,18 +53,32 @@ wifi:
 
 dashboard_import:
   package_import_url: github://mhendriks/esphome-p1/p1-dongle-pro-h2o-v2.yaml@main
+
+external_components:
+#   - source: my_components
+#     components: [ dsmr ]
+  - source: github://mhendriks/esphome-p1@main
+    components: [dsmr]
+
 
 # Enable logging
 logger:
   level: ERROR
 
 dsmr:
+  uart_id: p1_uart
+  max_telegram_length: 1700
 uart:
-  rx_pin:
-    number: 4
-    inverted: true
-  baud_rate: 115200
-  rx_buffer_size: 1700
+  - id: p1_uart
+    rx_pin:
+      number: 4
+      inverted: true
+    baud_rate: 115200
+    rx_buffer_size: 1700
+  - id: p1_bridge_uart
+    tx_pin:
+      number: 10
+    baud_rate: 115200
 
 status_led:
   pin:
@@ -235,6 +249,14 @@ sensor:
     update_interval: 60s
 
 text_sensor:
+  - platform: dsmr
+    telegram:
+      name: "telegram"
+      disabled_by_default: true
+      on_value:
+        then:
+          - lambda: |-
+              p1_bridge_uart->write_str(x.c_str());
   - platform: dsmr
     identification:
       name: "DSMR Identification"