From 842339a60e41a9042cc7b08b948dc76f07c5bf81 Mon Sep 17 00:00:00 2001
From: Greenman999 <mail@greenman999.de>
Date: Thu, 11 Sep 2025 17:16:12 +0200
Subject: [PATCH] feat: add basic i2c receiver and sender

---
 main.py | 70 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 70 insertions(+)
 create mode 100755 main.py

diff --git a/main.py b/main.py
new file mode 100755
index 0000000..bd20a5f
--- /dev/null
+++ b/main.py
@@ -0,0 +1,70 @@
+#!/usr/bin/env python
+import sys
+import time
+from smbus2 import SMBus, i2c_msg
+
+def listen_i2c(bus_number, address, register=0x00):
+    """
+    Listens for incoming data on the specified I2C address and prints received bytes.
+    :param bus_number: I2C bus number (e.g. 1 for /dev/i2c-1)
+    :param address: I2C address to listen to (in integer, e.g. 0x48)
+    :param register: Register to read from (default 0x00)
+    """
+    bus = SMBus(bus_number)
+    print(f"Listening on I2C bus {bus_number}, address {hex(address)}, register {hex(register)}")
+    try:
+        # color = True
+        while True:
+            try:
+                msg = i2c_msg.read(address, 8)  # Read 8 bytes!
+                bus.i2c_rdwr(msg)
+                data = bytes(msg)
+                int_list = list(data)
+                print(f"Received: {int_list}")
+                # Try reading 1 byte from the register
+                # data = bus.read_block_data(address, register)
+                # print(f"Received: ({data})")
+                # if color:
+                #     msg = i2c_msg.write(address, create_led_color_packet(255, 0, 0))
+                # else:
+                #     msg = i2c_msg.write(address, create_led_color_packet(255, 255, 0))
+                #
+                # bus.i2c_rdwr(msg)
+                # color = not(color)
+                # bus.write_i2c_block_data(address, register, create_led_color_packet(255, 0, 0))
+                # print("Write")
+            except Exception as e:
+                print(f"Write error: {e}")
+            time.sleep(0.5)
+    except KeyboardInterrupt:
+        print("Stopped listening.")
+    finally:
+        bus.close()
+
+def create_led_color_packet(r, g, b):
+    """
+    Create an 8-byte packet to set LED color for I2C transfer.
+    Packet format:
+    [0x10, 0x00, R, G, B, 0x00, 0x00, checksum]
+    - 0x10: Command for LED color
+    - 0x00: Target/channel (set as needed)
+    - R, G, B: Color bytes (0-255)
+    - 0x00, 0x00: Unused
+    - checksum: XOR of bytes 0-6
+    """
+    packet = [0x10, 0x00, r & 0xFF, g & 0xFF, b & 0xFF, 0x00, 0x00]
+    checksum = 0
+    for b in packet:
+        checksum ^= b
+    packet.append(checksum)
+    return bytes(packet)
+
+if __name__ == "__main__":
+    if len(sys.argv) < 3:
+        print("Usage: python i2c_listener.py <bus_number> <address> [register]")
+        print("Example: python i2c_listener.py 1 0x48")
+        sys.exit(1)
+    bus_number = int(sys.argv[1])
+    address = int(sys.argv[2], 0)
+    register = int(sys.argv[3], 0) if len(sys.argv) > 3 else 0x00
+    listen_i2c(bus_number, address, register)