Robot: Teensy 3.6 with the old robot's servo wiring and calibration

- LEGACY/Hexapod_Teensy/: old robot sketch (reference only).
- platformio.ini: robot env targets teensy36 (owner-confirmed board).
- Config.h: per-servo SERVOS table (pin, pulse at 0 deg, signed
  us/deg, pulse limits) built from the old sketch's pins, ranges, trims
  and the old Unity servo directions. Rear-left/front-left coxa offsets
  set to 0: the owner re-horns those two servos (the old +-90 left them
  at the end of travel; the sim showed them clamping).
- ServoDriver: 18 servos on hardware PWM (50 Hz, 16-bit); the Teensy 3.6
  Servo library stops at 12.
- Radio on CE 39 / CSN 15 with SPI SCK on pin 14.
- sim: analogWrite/PWM shims, pulses decoded through SERVOS (API v6).
- Docs: CLAUDE.md, READMEs.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

2026-current/LEGACY/Hexapod_Teensy/Nrf.h

@@ -0,0 +1,66 @@
+#include <SPI.h>
+#include "RF24.h"
+#include <RF24Network.h>
+#include "TransferDataStructure.h"
+
+// Nrf24 settings
+RF24 radio(39, 15); // CE, CSN
+RF24Network network(radio);
+
+const uint16_t this_node = 01;        // Address of our node in Octal format
+const uint16_t other_node = 00;       // Address of the other node in Octal format
+
+void NrfInit()
+{
+  SPI.setSCK(14);
+  SPI.setMOSI(11);
+  SPI.setMISO(12);
+
+  SPI.begin();
+  radio.begin();
+  network.begin(/*channel*/ 90, /*node address*/ this_node);
+
+  // Set the PA Level low to prevent power supply related issues since this is a
+  // getting_started sketch, and the likelihood of close proximity of the devices. RF24_PA_MAX is default.
+  radio.setPALevel(RF24_PA_LOW);
+}
+
+dataStruct2 NrfGetData(dataStruct2 data, bool debug = false)
+{
+  //  network.update();
+  int timeout = millis() + 100;
+  while ( network.available() && timeout > millis() )
+  {
+    RF24NetworkHeader header;
+    network.read(header, &data, sizeof(data));
+
+    if (debug)
+    {
+      Serial.print("Received packet ");
+      Serial.println(data.servoPositions[0]);
+    }
+  }
+
+  return data;
+}
+
+dataStruct2 NrfSendData(dataStruct2 data, bool debug = false)
+{
+  //  network.update();
+
+  if (debug)
+    Serial.print("Sending...");
+
+  RF24NetworkHeader header(/*to node*/ other_node);
+  bool ok = network.write(header, &data, sizeof(data));
+
+  if (debug)
+  {
+    if (ok)
+      Serial.println("ok.");
+    else
+      Serial.println("failed.");
+  }
+
+  return data;
+}