From 89b31949145c78295ab77914328e57a1f1779615 Mon Sep 17 00:00:00 2001
From: ryleu <69326171+ryleu@users.noreply.github.com>
Date: Thu, 2 Apr 2026 19:41:05 -0500
Subject: [PATCH] update documentation and accept 3-value VicCAN messages

---
 src/anchor_pkg/anchor_pkg/anchor_node.py | 5 ++++-
 src/anchor_pkg/anchor_pkg/connector.py   | 4 +++-
 src/anchor_pkg/anchor_pkg/convert.py     | 2 ++
 3 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/src/anchor_pkg/anchor_pkg/anchor_node.py b/src/anchor_pkg/anchor_pkg/anchor_node.py
index 8edc8b5..b9cf992 100644
--- a/src/anchor_pkg/anchor_pkg/anchor_node.py
+++ b/src/anchor_pkg/anchor_pkg/anchor_node.py
@@ -42,6 +42,9 @@ class Anchor(Node):
         - Core, Arm, and Bio publish VicCAN messages to this topic to send to the MCU
     * /anchor/to_vic/relay_string
         - Send raw strings to connectors. Does not work for connectors that require conversion (like CANConnector)
+    * /anchor/relay
+        - Legacy method for talking to connectors. Takes String as input, but does not send the raw strings to connectors.
+          Instead, it converts them to VicCAN messages first.
     """
 
     connector: Connector
@@ -203,7 +206,7 @@ class Anchor(Node):
         self.connector.write(msg)
         self.tovic_debug_pub_.publish(msg)
 
-    @deprecated("Use /anchor/to_vic/relay instead of /anchor/relay")
+    @deprecated("Use /anchor/to_vic/relay or /anchor/to_vic/relay_string instead of /anchor/relay")
     def write_connector_legacy(self, msg: String):
         """Write to the connector by first attempting to convert String to VicCAN"""
         # please do not reference this code. ~riley
diff --git a/src/anchor_pkg/anchor_pkg/connector.py b/src/anchor_pkg/anchor_pkg/connector.py
index e9859bb..0e8fffe 100644
--- a/src/anchor_pkg/anchor_pkg/connector.py
+++ b/src/anchor_pkg/anchor_pkg/connector.py
@@ -372,8 +372,10 @@ class CANConnector(Connector):
             case 2:
                 data_type = 1
                 data = struct.pack(">ff", *msg.data)
-            case 4:
+            case 3 | 4: # 3 gets padded and is treated as 4
                 data_type = 2
+                # pad till we have 4 otherwise struct.pack will freak out
+                msg.data = (msg.data + [0])[:4]
                 data = struct.pack(">hhhh", *[int(x) for x in msg.data])
             case _:
                 self.logger.error(
diff --git a/src/anchor_pkg/anchor_pkg/convert.py b/src/anchor_pkg/anchor_pkg/convert.py
index cfecfce..57b2c44 100644
--- a/src/anchor_pkg/anchor_pkg/convert.py
+++ b/src/anchor_pkg/anchor_pkg/convert.py
@@ -57,6 +57,8 @@ def string_to_viccan(
 
 def viccan_to_string(viccan: VicCAN) -> str:
     """Converts a ROS2 VicCAN message to the serial string VicCAN format."""
+    # make sure we accept 3 digits and treat it as 4
+    if len(viccan.data) == 3: viccan.data.append("0")
     # go from [ w, x, y, z ] -> ",w,x,y,z" & round to 7 digits max
     data = "".join([f",{round(val,7)}" for val in viccan.data])
     return f"can_relay_tovic,{viccan.mcu_name},{viccan.command_id}{data}\n"