From cbb0d672f6e67fa3b6f6e50b0ef06f5f61fb0cd4 Mon Sep 17 00:00:00 2001
From: Eddy de Vink <github@eddydev.ink>
Date: Thu, 13 Aug 2026 12:17:54 +0200
Subject: [PATCH] Add module identification command (relay id)

---
 README.md    |  1 +
 relay        | 11 ++++++-----
 src/main.cpp |  3 +++
 3 files changed, 10 insertions(+), 5 deletions(-)

diff --git a/README.md b/README.md
index fde58ae..4a0dd8c 100644
--- a/README.md
+++ b/README.md
@@ -10,6 +10,7 @@ Sluit aan via USB en stuur commando's:
 ./relay 1   # relais aan
 ./relay 0   # relais uit
 ./relay 1 /dev/cu.usbserial-XXXX   # poort opgeven als default afwijkt
+./relay id  # toont module-ID (chip-ID, uniek per chip, onafhankelijk van USB-poort)
 ```
 
 ## Pinnen
diff --git a/relay b/relay
index 9429222..405c5bb 100755
--- a/relay
+++ b/relay
@@ -1,15 +1,16 @@
 #!/usr/bin/env python3
-"""Toggle the USB relay via serial: ./relay 1|0 [serial_port]."""
+"""Toggle the USB relay via serial: ./relay 1|0|id [serial_port]."""
 import sys
 import serial
 
 DEFAULT_PORT = "/dev/cu.usbserial-2110"
 
 def main() -> int:
-    if len(sys.argv) not in (2, 3) or sys.argv[1] not in ("0", "1"):
-        print(f"Usage: {sys.argv[0]} 0|1 [serial_port]", file=sys.stderr)
+    if len(sys.argv) not in (2, 3) or sys.argv[1] not in ("0", "1", "id"):
+        print(f"Usage: {sys.argv[0]} 0|1|id [serial_port]", file=sys.stderr)
         return 1
     command = sys.argv[1]
+    serial_cmd = "?" if command == "id" else command
     port = sys.argv[2] if len(sys.argv) == 3 else DEFAULT_PORT
     try:
         # dtr/rts expliciet uit vóór open: voorkomt (of beperkt) de CH340
@@ -32,12 +33,12 @@ def main() -> int:
         # binnen 2 s (timeout, readline geeft b"") = geen reset: door.
         s.readline()
         s.reset_input_buffer()
-        s.write(command.encode())
+        s.write(serial_cmd.encode())
         s.flush()
         reply = s.readline().decode(errors="replace").strip()
     finally:
         s.close()
-    if reply in ("ON", "OFF"):
+    if reply in ("ON", "OFF") or (command == "id" and reply.startswith("ID ")):
         print(reply)
         return 0
     print(f"ERROR: no valid reply from board (got {reply!r})", file=sys.stderr)
diff --git a/src/main.cpp b/src/main.cpp
index dad1b9e..a8846ec 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -23,6 +23,9 @@ void loop() {
       digitalWrite(RELAY_PIN, LOW);
       digitalWrite(LED_PIN, HIGH);
       Serial.println("OFF");
+    } else if (c == '?') {
+      Serial.print("ID usbtoggle-relay ");
+      Serial.println(ESP.getChipId(), HEX);
     }
   }
 }