From 4d10491e6e2caea47c2e93c127f2fbeedd7291b3 Mon Sep 17 00:00:00 2001
From: Fjen Undso <fjen@neboola.de>
Date: Tue, 23 Jan 2018 22:23:57 +0100
Subject: [PATCH] esp: add hostid in data header

---
 README.md   |  9 ++++++---
 esp/main.py | 23 +++++++++++++++++++++--
 2 files changed, 27 insertions(+), 5 deletions(-)

diff --git a/README.md b/README.md
index 9a2877a..fde558c 100644
--- a/README.md
+++ b/README.md
@@ -8,7 +8,7 @@
 
 The node listens on udp port 1234 and expects packets of following layout:
 
-    [VER:8][SEQ:8][ OFFSET:16  ]
+    [VER:8][SEQ:8][ID:8 ][RES:8]
     [        PIXEL:32*n        ]
     [           ...            ]
     [           ...            ]
@@ -19,8 +19,11 @@ The node listens on udp port 1234 and expects packets of following layout:
    - value: 2
  - SEQ: sequence number
    - this should be incremented for each datagram
- - OFFSET: (ignored/WIP) defines where the first pixel should be drawn
+ - ID: receiver address id
+   - ID of the node is the number in its hostname. can be 0 to address all
+ - RES: reserved for future use.
+   - (WIP/idea) defines where the first pixel should be drawn
    - default: 0
- - PIXEL: colors in grbw format
+ - PIXEL: colors in GRBW format
    - 1 <= n <= pixel count
 
diff --git a/esp/main.py b/esp/main.py
index 321544d..1160b97 100644
--- a/esp/main.py
+++ b/esp/main.py
@@ -2,13 +2,17 @@ import socket
 import machine
 import neopixel
 import utime
+import wifi_config
 
+
+# config
 PORT = 1234
 SIGNAL_LED_PIN = 2
 LED_PIN = 0
 LED_NUM = 42
-LED_PIXEL = 4  # pixel per led (3 or 4)
+LED_PIXEL = 4  # pixel per led (4 for RGBW)
 
+ESP_ID = int(''.join(c for c in wifi_config.HOSTNAME if c.isdigit()))
 machine.freq(160000000)
 
 gamma8 = [
@@ -102,9 +106,24 @@ class UDPled:
 
     @micropython.native
     def run_fast_seq(self):
-        """Receives SEQ|GRBW|... as a UDP packet. Must contain all LEDs"""
+        """Receives a UDP packet with header. Must contain all LEDs.
+
+        Packet format:
+            [VER:8][SEQ:8][ID:8 ][RES:8]
+            [        PIXEL:4*8         ]
+            [           ...            ]
+
+        VER: protocol version number (currently 2)
+        SEQ: sequence number
+        ID: the host id of this ESP. Ignored if 0
+        RES: reserved for future use
+        PIXEL: 8bit GRBW values for a pixel
+        """
         while True:
             self.sock.readinto(self.udp_buffer)
+            if self.udp_buffer[2] not in [0, ESP_ID]:
+                # ignore packet if it's not for us or everyone
+                continue
             if (self.udp_buffer[0] == 2 and (self.udp_buffer[1] - self.udp_seq)%256 <= 128):
                 self.udp_seq = self.udp_buffer[1]
                 self.np.buf = self.udp_buffer[4:]
-- 
GitLab