diff --git a/.gitignore b/.gitignore
index a81693dc..84f88302 100644
--- a/.gitignore
+++ b/.gitignore
@@ -12,5 +12,8 @@ build_cache
 Configuration_local*
 MeadeToWikiOutput.txt
 
+!Configuration_local_examples/
+!Configuration_local_examples/*
+
 # macOS
 **/.DS_Store
diff --git a/Configuration.hpp b/Configuration.hpp
index bebb8c7c..353208bd 100644
--- a/Configuration.hpp
+++ b/Configuration.hpp
@@ -273,6 +273,10 @@
     #include "boards/AVR_MKS_GEN_L_V2/pins_MKS_GEN_L_V2.h"
 #elif (BOARD == BOARD_AVR_MKS_GEN_L_V21)
     #include "boards/AVR_MKS_GEN_L_V21/pins_MKS_GEN_L_V21.h"
+#elif (BOARD == BOARD_RP2040_JACKW01)
+    #include "boards/RP2040_JACKW01/pins_RP2040_JACKW01.hpp"
+#elif (BOARD == BOARD_RP2040_SKR_PICO)
+    #include "boards/RP2040_SKR_PICO/pins_RP2040_SKR_PICO.hpp"
 #endif
 
 #include "Configuration_adv.hpp"
diff --git a/ConfigurationValidation.hpp b/ConfigurationValidation.hpp
index eb31aedb..190d306e 100644
--- a/ConfigurationValidation.hpp
+++ b/ConfigurationValidation.hpp
@@ -17,7 +17,7 @@
 #endif
 
 // Platform
-#if defined(ESP32) || defined(__AVR_ATmega2560__)
+#if defined(ESP32) || defined(__AVR_ATmega2560__) || defined(ARDUINO_ARCH_RP2040)
 // Valid platform
 #else
     #error Unsupported platform configuration. Use at own risk.
@@ -30,6 +30,8 @@
     && ((DISPLAY_TYPE == DISPLAY_TYPE_NONE) || (DISPLAY_TYPE == DISPLAY_TYPE_LCD_KEYPAD) || (DISPLAY_TYPE_LCD_KEYPAD_I2C_MCP23008)         \
         || (DISPLAY_TYPE_LCD_KEYPAD_I2C_MCP23017))
 // Valid display for ATmega
+#elif defined(ARDUINO_ARCH_RP2040) && (DISPLAY_TYPE == DISPLAY_TYPE_NONE)
+// Valid display for RP2040
 #else
     #error Unsupported display configuration. Use at own risk.
 #endif
@@ -81,7 +83,7 @@
     #else
         #error Defined an AZ driver, but no AZ stepper.
     #endif
-#elif defined(__AVR_ATmega2560__)
+#elif defined(__AVR_ATmega2560__) || defined(ARDUINO_ARCH_RP2040)
     // Azimuth configuration
     #if (AZ_DRIVER_TYPE == DRIVER_TYPE_TMC2209_UART)
         #ifndef AZ_DRIVER_ADDRESS
@@ -102,7 +104,7 @@
     #else
         #error Defined an ALT driver, but no ALT stepper.
     #endif
-#elif defined(__AVR_ATmega2560__)
+#elif defined(__AVR_ATmega2560__) || defined(ARDUINO_ARCH_RP2040)
     // Altitude configuration
     #if (ALT_DRIVER_TYPE == DRIVER_TYPE_TMC2209_UART)
         #ifndef ALT_DRIVER_ADDRESS
@@ -166,8 +168,8 @@
 // External sensors
 #if (USE_GPS == 0)
 // Baseline configuration without GPS is valid
-#elif defined(ESP32) || defined(__AVR_ATmega2560__)
-// GPS is supported on ESP32 and ATmega
+#elif defined(ESP32) || defined(__AVR_ATmega2560__) || defined(ARDUINO_ARCH_RP2040)
+// GPS is supported on ESP32, ATmega and RP2040
 #else
     #error Unsupported GPS configuration. Use at own risk.
 #endif
@@ -238,6 +240,12 @@
             // Required pin assignments missing (ATmega uses SoftwareSerial for this driver)
             #error Missing pin assignments for configured AZ DRIVER_TYPE_TMC2209_UART driver
         #endif
+        #if !defined(AZ_DIAG_PIN)
+            // AZ_DIAG_PIN (TMC2209 DIAG output) is used only for stallGuard-based homing.
+            // It is optional: omit it if your hardware does not wire the DIAG output to a GPIO.
+            // Without it, stallGuard homing is unavailable but all other AZ motion works normally.
+            #pragma message "AZ_DIAG_PIN not defined. StallGuard homing unavailable for AZ axis."
+        #endif
         #if !((defined(AZ_SERIAL_PORT_TX) && defined(AZ_SERIAL_PORT_RX)) || defined(AZ_SERIAL_PORT))
             // Required pin assignments missing for UART serial
             #error Missing pin assignments for configured AZ DRIVER_TYPE_TMC2209_UART driver serial connection
@@ -256,6 +264,12 @@
             // Required pin assignments missing (ATmega uses SoftwareSerial for this driver)
             #error Missing pin assignments for configured ALT DRIVER_TYPE_TMC2209_UART driver
         #endif
+        #if !defined(ALT_DIAG_PIN)
+            // ALT_DIAG_PIN (TMC2209 DIAG output) is used only for stallGuard-based homing.
+            // It is optional: omit it if your hardware does not wire the DIAG output to a GPIO.
+            // Without it, stallGuard homing is unavailable but all other ALT motion works normally.
+            #pragma message "ALT_DIAG_PIN not defined. StallGuard homing unavailable for ALT axis."
+        #endif
         #if !((defined(ALT_SERIAL_PORT_TX) && defined(ALT_SERIAL_PORT_RX)) || defined(ALT_SERIAL_PORT))
             // Required pin assignments missing for UART serial
             #error Missing pin assignments for configured ALT DRIVER_TYPE_TMC2209_UART driver serial connection
diff --git a/Configuration_local_examples/Configuration_local_rp2040_skr_pico.hpp b/Configuration_local_examples/Configuration_local_rp2040_skr_pico.hpp
new file mode 100644
index 00000000..a757cfe5
--- /dev/null
+++ b/Configuration_local_examples/Configuration_local_rp2040_skr_pico.hpp
@@ -0,0 +1,154 @@
+/**
+ * @brief Local hardware configuration for a Raspberry Pi Pico (RP2040)
+ *        on the BigTreeTech SKR Pico v1.0 printer controller board.
+ *
+ * This file is NOT tracked by Git and will survive branch changes.
+ * It is automatically included by LocalConfiguration.hpp when
+ * BOARD == BOARD_RP2040_SKR_PICO.
+ *
+ * Hardware summary
+ * ----------------
+ *  MCU          : RP2040 (Raspberry Pi Pico)
+ *  Board        : BTT SKR Pico v1.0
+ *  Stepper slot : X  -> RA    (TMC2209, UART addr 0)
+ *  Stepper slot : Y  -> DEC   (TMC2209, UART addr 2)
+ *  Stepper slot : Z  -> AZ    (TMC2209, UART addr 1)
+ *  Stepper slot : E0 -> ALT   (TMC2209, UART addr 3)
+ *  Motor rating : 0.9 deg / step (400 SPR), 470 mA
+ *  Pulley       : 16T aluminium GT2
+ *  RA homing    : Hall sensor on GPIO4 (X-STOP / RA_DIAG_PIN)
+ *
+ * All pin assignments are in boards/RP2040_SKR_PICO/pins_RP2040_SKR_PICO.hpp.
+ * R_SENSE (0.11 ohm) is set globally in src/a_inits.hpp for all TMC2209_UART
+ * builds and does not need to be repeated here.
+ *
+ * Key difference from JackW01: each stepper driver has its own EN pin.
+ * AZ_ALWAYS_ON and ALT_ALWAYS_ON are NOT required on this board.
+ */
+#pragma once
+
+// ── Board ─────────────────────────────────────────────────────────────────────
+#define BOARD BOARD_RP2040_SKR_PICO
+
+// ── Hemisphere ────────────────────────────────────────────────────────────────
+#define NORTHERN_HEMISPHERE 1
+
+// ── Display (none) ────────────────────────────────────────────────────────────
+#define DISPLAY_TYPE      DISPLAY_TYPE_NONE
+#define INFO_DISPLAY_TYPE INFO_DISPLAY_TYPE_NONE
+
+// ── Stepper motor types ───────────────────────────────────────────────────────
+#define RA_STEPPER_TYPE  STEPPER_TYPE_ENABLED
+#define DEC_STEPPER_TYPE STEPPER_TYPE_ENABLED
+#define AZ_STEPPER_TYPE  STEPPER_TYPE_ENABLED
+#define ALT_STEPPER_TYPE STEPPER_TYPE_ENABLED
+
+// ── Stepper driver types ──────────────────────────────────────────────────────
+#define RA_DRIVER_TYPE  DRIVER_TYPE_TMC2209_UART
+#define DEC_DRIVER_TYPE DRIVER_TYPE_TMC2209_UART
+#define AZ_DRIVER_TYPE  DRIVER_TYPE_TMC2209_UART
+#define ALT_DRIVER_TYPE DRIVER_TYPE_TMC2209_UART
+
+// ── Steps per revolution (0.9 deg motor = 400 full steps/rev) ─────────────────
+#define RA_STEPPER_SPR  400
+#define DEC_STEPPER_SPR 400
+#define AZ_STEPPER_SPR  400
+#define ALT_STEPPER_SPR 400
+
+// ── Pulley tooth count (16T aluminium GT2) ────────────────────────────────────
+#define RA_PULLEY_TEETH  16
+#define DEC_PULLEY_TEETH 16
+#define AZ_PULLEY_TEETH  16
+#define ALT_PULLEY_TEETH 16
+
+// ── Microstepping ─────────────────────────────────────────────────────────────
+// TMC2209 UART mode can switch microstepping dynamically at runtime.
+// RA switches between slew (8×) and fine tracking (256×).
+// DEC switches between slew (16×) and fine guiding (256×).
+// AZ and ALT use a fixed microstepping mode (no dynamic switching).
+#define RA_SLEW_MICROSTEPPING     8    // µsteps used while slewing RA
+#define RA_TRACKING_MICROSTEPPING 256  // µsteps used for sidereal tracking
+#define DEC_SLEW_MICROSTEPPING    16   // µsteps used while slewing DEC
+#define DEC_GUIDE_MICROSTEPPING   256  // µsteps used for guide pulses
+#define AZ_MICROSTEPPING          64
+#define ALT_MICROSTEPPING         4
+
+// ── Motor direction ───────────────────────────────────────────────────────────
+// Set to 1 to reverse the direction of an axis if it moves the wrong way.
+// Verify with manual move commands: :Mw#/:Me# (RA), :Mn#/:Ms# (DEC),
+// :MAL#/:MAR# (AZ), :MAU#/:MAD# (ALT).  Then set the appropriate flag to 1.
+#define RA_INVERT_DIR  0
+#define DEC_INVERT_DIR 1
+#define AZ_INVERT_DIR  0
+#define ALT_INVERT_DIR 0
+
+// ── StealthChop (silent mode) ─────────────────────────────────────────────────
+// Configuration_adv.hpp defaults both to 0 (SpreadCycle = noisy).
+// Set to 1 to enable StealthChop (silent) for RA tracking and DEC moves.
+#define RA_UART_STEALTH_MODE  1
+#define DEC_UART_STEALTH_MODE 1
+
+// ── Motor current ─────────────────────────────────────────────────────────────
+// Motors are rated at 470 mA.  Run at 75 % of rated current to reduce heat
+// while maintaining adequate torque.  RMS current is computed automatically:
+//   RMSCURRENT = RATING * (SETTING / 100) / sqrt(2)  => ~249 mA RMS
+// Do NOT define XXX_RMSCURRENT directly; Configuration_adv.hpp will error.
+#define RA_MOTOR_CURRENT_RATING      470  // mA
+#define RA_OPERATING_CURRENT_SETTING 75   // %
+
+#define DEC_MOTOR_CURRENT_RATING      470  // mA
+#define DEC_OPERATING_CURRENT_SETTING 75   // %
+
+#define AZ_MOTOR_CURRENT_RATING      470  // mA
+#define AZ_OPERATING_CURRENT_SETTING 75   // %
+
+#define ALT_MOTOR_CURRENT_RATING      470  // mA
+#define ALT_OPERATING_CURRENT_SETTING 75   // %
+
+// ── AZ/ALT hold current ───────────────────────────────────────────────────────
+// AZ must hold position against backlash forces; use 40 % of run current.
+// ALT is held by friction and gearing; bleed hold current to zero.
+// These are percentages (0-100) converted to TMC2209 IHOLD by the firmware.
+#define AZ_MOTOR_HOLD_SETTING  40  // %
+#define ALT_MOTOR_HOLD_SETTING 0   // %
+
+// ── DEC axis travel limits ────────────────────────────────────────────────────
+// Physical limits measured from the home (level) position.
+// These must be defined here; Configuration_adv.hpp defaults to 0.0f for
+// non-OAM builds, which makes :Mn#/:Ms# target position 0 and do nothing.
+#ifndef DEC_LIMIT_UP
+    #define DEC_LIMIT_UP 135.0f  // 135° north of home
+#endif
+#ifndef DEC_LIMIT_DOWN
+    #define DEC_LIMIT_DOWN 35.0f  // 35° south of home
+#endif
+
+// ── RA Hall sensor auto-home ──────────────────────────────────────────────────
+// Hall sensor is wired to GPIO4 (X-STOP input / RA_DIAG_PIN on SKR Pico).
+// Active state LOW: sensor pulls GPIO4 LOW when the magnet is present.
+// Search distance: 30° default (RA_HOMING_SENSOR_SEARCH_DEGREES in Configuration_adv.hpp).
+// GPIO4 is configured INPUT (no pull-up); add external 10kΩ to 3.3V if sensor
+// is open-drain, or change to INPUT_PULLUP in b_setup.hpp.
+#define USE_HALL_SENSOR_RA_AUTOHOME   1
+#define RA_HOMING_SENSOR_PIN          4    // GPIO4 = RA_DIAG_PIN (X-STOP)
+#define RA_HOMING_SENSOR_ACTIVE_STATE LOW  // sensor pulls LOW when active
+
+// ── GPS ───────────────────────────────────────────────────────────────────────
+// ATGM336H-5N wired to left-side header: GPS TX→IO1, GPS RX→IO0, VCC→5V, GND.
+// GPS_SERIAL_PORT, RP2040_GPS_TX_PIN, RP2040_GPS_RX_PIN defined in pins file.
+// GPS_BAUD_RATE defaults to 9600 in Configuration_adv.hpp (matches module default).
+#define USE_GPS 1
+
+// ── FAN ───────────────────────────────────────────────────────────────────────
+// FAN1 power level as a percentage (0 = off, 100 = full speed).
+// The pin and PWM are defined in pins_RP2040_SKR_PICO.hpp.
+#define RP2040_FAN1_POWER_PERCENT 60
+
+// Track immediately after boot
+#define TRACK_ON_BOOT 0
+
+// Uncomment to override defaults for stepper speeds and accelerations
+//#define RA_STEPPER_SPEED 1200  // You can change the speed and acceleration of the steppers here. Max. Speed = 3000.
+//#define RA_STEPPER_ACCELERATION 6000
+//#define DEC_STEPPER_SPEED 1300  // You can change the speed and acceleration of the steppers here. Max. Speed = 3000.
+//#define DEC_STEPPER_ACCELERATION 6000
diff --git a/Constants.hpp b/Constants.hpp
index e37811b2..56ccb6ce 100644
--- a/Constants.hpp
+++ b/Constants.hpp
@@ -21,6 +21,10 @@
 #define BOARD_ESP32_ESP32DEV 1001
 #define BOARD_OAE_V1         1002
 
+// RP2040 based boards
+#define BOARD_RP2040_JACKW01  2101
+#define BOARD_RP2040_SKR_PICO 2201
+
 /**
  * Supported keypad/display types. Use one of these values for DISPLAY_TYPE configuration matching your used display and keypad.
  * 
diff --git a/LocalConfiguration.hpp b/LocalConfiguration.hpp
index 14a00510..428fd3c7 100644
--- a/LocalConfiguration.hpp
+++ b/LocalConfiguration.hpp
@@ -18,6 +18,10 @@
     #include "Configuration_local_esp32dev.hpp"
 #elif BOARD == BOARD_OAE_V1 && __has_include("Configuration_local_oae.hpp")
     #include "Configuration_local_oae.hpp"
+#elif BOARD == BOARD_RP2040_JACKW01 && __has_include("Configuration_local_rp2040_jackw01.hpp")
+    #include "Configuration_local_rp2040_jackw01.hpp"
+#elif BOARD == BOARD_RP2040_SKR_PICO && __has_include("Configuration_local_rp2040_skr_pico.hpp")
+    #include "Configuration_local_rp2040_skr_pico.hpp"
 #elif __has_include("Configuration_local.hpp")
     #include "Configuration_local.hpp"
 #endif
\ No newline at end of file
diff --git a/boards/RP2040_JACKW01/pins_RP2040_JACKW01.hpp b/boards/RP2040_JACKW01/pins_RP2040_JACKW01.hpp
new file mode 100644
index 00000000..a467647b
--- /dev/null
+++ b/boards/RP2040_JACKW01/pins_RP2040_JACKW01.hpp
@@ -0,0 +1,141 @@
+/**
+ * @brief Pin configuration for a Raspberry Pi Pico (RP2040/RP2350) mounted on
+ *        the JackW01 pi-pico-printer-board carrier (https://github.com/jackw01/pi-pico-printer-board).
+ *
+ * Stepper slot mapping:
+ *   X slot  -> RA  (TMC2209 UART address 0)
+ *   Y slot  -> DEC (TMC2209 UART address 1)
+ *   Z slot  -> AZ  (TMC2209 UART address 2)
+ *   E slot  -> ALT (TMC2209 UART address 3)
+ *
+ * All four stepper enable lines are tied together to a single GPIO on this
+ * board (GPIO5). Define every axis EN pin to the same value so the firmware
+ * compiles cleanly; in practice enabling/disabling one axis affects all.
+ * Per-axis power management should be handled via the TMC2209 IHOLD register
+ * over UART rather than toggling EN.
+ *
+ * TMC2209 UART: all four drivers share a single-wire bus on UART1.
+ *   TX -> GPIO8  (UART1 TX)
+ *   RX -> GPIO9  (UART1 RX)
+ * Pin remapping must be applied before Serial2.begin() in platform setup:
+ *   Serial2.setTX(RP2040_UART1_TX_PIN);
+ *   Serial2.setRX(RP2040_UART1_RX_PIN);
+ */
+
+#pragma once
+
+// ── RA axis (X slot, TMC2209 address 0) ──────────────────────────────────────
+#ifndef RA_STEP_PIN
+    #define RA_STEP_PIN 7
+#endif
+#ifndef RA_DIR_PIN
+    #define RA_DIR_PIN 6
+#endif
+#ifndef RA_EN_PIN
+    #define RA_EN_PIN 5  // Shared with all axes on this board
+#endif
+#ifndef RA_DIAG_PIN
+    #define RA_DIAG_PIN 4  // X endstop input - used for Hall sensor RA homing
+#endif
+
+// RA TMC2209 UART
+#ifndef RA_SERIAL_PORT
+    #define RA_SERIAL_PORT Serial2  // UART1 via Philhower Serial2
+#endif
+#ifndef RA_DRIVER_ADDRESS
+    #define RA_DRIVER_ADDRESS 0b00  // MS1=LOW, MS2=LOW
+#endif
+
+// ── DEC axis (Y slot, TMC2209 address 2) ─────────────────────────────────────
+#ifndef DEC_STEP_PIN
+    #define DEC_STEP_PIN 11
+#endif
+#ifndef DEC_DIR_PIN
+    #define DEC_DIR_PIN 10
+#endif
+#ifndef DEC_EN_PIN
+    #define DEC_EN_PIN 5  // Shared with all axes on this board
+#endif
+#ifndef DEC_DIAG_PIN
+    #define DEC_DIAG_PIN 3  // Y endstop input
+#endif
+
+// DEC TMC2209 UART
+#ifndef DEC_SERIAL_PORT
+    #define DEC_SERIAL_PORT Serial2  // Shared UART1 bus
+#endif
+#ifndef DEC_DRIVER_ADDRESS
+    #define DEC_DRIVER_ADDRESS 0b01  // MS1=HIGH, MS2=LOW -> address 1
+#endif
+
+// ── AZ axis (Z slot, TMC2209 address 1) ──────────────────────────────────────
+#ifndef AZ_STEP_PIN
+    #define AZ_STEP_PIN 13
+#endif
+#ifndef AZ_DIR_PIN
+    #define AZ_DIR_PIN 12
+#endif
+#ifndef AZ_EN_PIN
+    #define AZ_EN_PIN 5  // Shared with all axes on this board
+#endif
+
+// AZ TMC2209 UART
+#ifndef AZ_SERIAL_PORT
+    #define AZ_SERIAL_PORT Serial2  // Shared UART1 bus
+#endif
+#ifndef AZ_DRIVER_ADDRESS
+    #define AZ_DRIVER_ADDRESS 0b10  // MS1=LOW, MS2=HIGH -> address 2
+#endif
+
+// ── ALT axis (Extruder slot, TMC2209 address 3) ───────────────────────────────
+#ifndef ALT_STEP_PIN
+    #define ALT_STEP_PIN 15
+#endif
+#ifndef ALT_DIR_PIN
+    #define ALT_DIR_PIN 14
+#endif
+#ifndef ALT_EN_PIN
+    #define ALT_EN_PIN 5  // Shared with all axes on this board
+#endif
+
+// ALT TMC2209 UART
+#ifndef ALT_SERIAL_PORT
+    #define ALT_SERIAL_PORT Serial2  // Shared UART1 bus
+#endif
+#ifndef ALT_DRIVER_ADDRESS
+    #define ALT_DRIVER_ADDRESS 0b11  // MS1=HIGH, MS2=HIGH -> address 3
+#endif
+
+// ── UART1 physical pin assignments ───────────────────────────────────────────
+// The JackW01 board routes UART to the TMC2209 drivers as follows:
+//   GPIO8 → R202 (1kΩ) → RESET/TX pad  (UART1 TX)
+//   GPIO9 → R201 (100Ω) → MS3/RX pad   (UART1 RX)
+//
+// BigTreeTech TMC2209 modules have an onboard resistor bridging their
+// RESET/TX and MS3/RX pads to PDN_UART, so both JackW01 lines reach
+// the TMC2209 PDN_UART pin.  Standard two-wire hardware UART1 is used:
+//   TX: GPIO8 (native UART1 TX mux function)
+//   RX: GPIO9 (native UART1 RX mux function)
+//
+// b_setup.hpp calls Serial2.setTX()/setRX() before Serial2.begin() to
+// remap UART1 to these pins.
+#ifndef RP2040_UART1_TX_PIN
+    #define RP2040_UART1_TX_PIN 8
+#endif
+#ifndef RP2040_UART1_RX_PIN
+    #define RP2040_UART1_RX_PIN 9
+#endif
+
+// All drivers use hardware UART (Serial2).
+#define SW_SERIAL_UART 0
+
+// ── Shared EN pin override ────────────────────────────────────────────────────
+// All four TMC2209 EN lines are wired together to GPIO5 on this board.
+// After per-axis init leaves GPIO5 in an indeterminate state, b_setup.hpp will
+// drive RP2040_SHARED_EN_PIN LOW once to enable all drivers together.
+#define RP2040_SHARED_EN_PIN 5
+
+// ── Debug serial port ─────────────────────────────────────────────────────────
+#ifndef DEBUG_SERIAL_PORT
+    #define DEBUG_SERIAL_PORT Serial  // USB CDC serial via Philhower core
+#endif
diff --git a/boards/RP2040_SKR_PICO/pins_RP2040_SKR_PICO.hpp b/boards/RP2040_SKR_PICO/pins_RP2040_SKR_PICO.hpp
new file mode 100644
index 00000000..0f8c835a
--- /dev/null
+++ b/boards/RP2040_SKR_PICO/pins_RP2040_SKR_PICO.hpp
@@ -0,0 +1,163 @@
+/**
+ * @brief Pin configuration for a Raspberry Pi Pico (RP2040) on the
+ *        BigTreeTech SKR Pico v1.0 printer controller board.
+ *
+ * Hardware reference: https://github.com/bigtreetech/SKR-Pico
+ * Authoritative pin source: Klipper/SKR Pico klipper.cfg
+ *
+ * Stepper slot mapping (OAT axis -> board slot -> TMC2209 UART address):
+ *   X slot  -> RA  (TMC2209 UART address 0)
+ *   Y slot  -> DEC (TMC2209 UART address 2)
+ *   Z slot  -> AZ  (TMC2209 UART address 1)
+ *   E0 slot -> ALT (TMC2209 UART address 3)
+ *
+ * Note: DEC uses address 2 and AZ uses address 1 — the opposite of the
+ *       JackW01 board.  This reflects the MS1/MS2 resistor strapping on
+ *       the SKR Pico PCB.
+ *
+ * Each stepper driver has its own dedicated EN pin (unlike the JackW01
+ * board where all EN lines share a single GPIO).  No RP2040_SHARED_EN_PIN
+ * is needed; AZ_ALWAYS_ON / ALT_ALWAYS_ON are not required.
+ *
+ * TMC2209 UART: all four drivers share a two-wire bus on UART1.
+ *   TX -> GPIO8  (UART1 TX, same physical assignment as JackW01)
+ *   RX -> GPIO9  (UART1 RX, same physical assignment as JackW01)
+ * Pin remapping is applied in b_setup.hpp via:
+ *   Serial2.setTX(RP2040_UART1_TX_PIN);
+ *   Serial2.setRX(RP2040_UART1_RX_PIN);
+ *
+ * The SKR Pico has on-board TMC2209 ICs with proper PDN_UART wiring
+ * (both TX and RX reach each driver).  No jumper is required.
+ *
+ * Endstop inputs (also usable as homing sensors):
+ *   X-STOP -> GPIO4  (RA Hall sensor / diag input)
+ *   Y-STOP -> GPIO3
+ *   Z-STOP -> GPIO25
+ *   E-STOP -> GPIO16
+ *
+ * Additional I/O:
+ *   BLTouch sensor  -> GPIO22
+ *   BLTouch control -> GPIO29
+ *   NeoPixel data   -> GPIO24
+ */
+
+#pragma once
+
+// ── RA axis (X slot, TMC2209 address 0) ──────────────────────────────────────
+#ifndef RA_STEP_PIN
+    #define RA_STEP_PIN 11
+#endif
+#ifndef RA_DIR_PIN
+    #define RA_DIR_PIN 10
+#endif
+#ifndef RA_EN_PIN
+    #define RA_EN_PIN 12  // Individual EN pin (active LOW)
+#endif
+#ifndef RA_DIAG_PIN
+    #define RA_DIAG_PIN 4  // X-STOP input - used for Hall sensor RA homing
+#endif
+
+// RA TMC2209 UART
+#ifndef RA_SERIAL_PORT
+    #define RA_SERIAL_PORT Serial2  // UART1 via Philhower Serial2
+#endif
+#ifndef RA_DRIVER_ADDRESS
+    #define RA_DRIVER_ADDRESS 0b00  // MS1=LOW, MS2=LOW -> address 0
+#endif
+
+// ── DEC axis (Y slot, TMC2209 address 2) ─────────────────────────────────────
+#ifndef DEC_STEP_PIN
+    #define DEC_STEP_PIN 6
+#endif
+#ifndef DEC_DIR_PIN
+    #define DEC_DIR_PIN 5
+#endif
+#ifndef DEC_EN_PIN
+    #define DEC_EN_PIN 7  // Individual EN pin (active LOW)
+#endif
+#ifndef DEC_DIAG_PIN
+    #define DEC_DIAG_PIN 3  // Y-STOP input
+#endif
+
+// DEC TMC2209 UART
+#ifndef DEC_SERIAL_PORT
+    #define DEC_SERIAL_PORT Serial2  // Shared UART1 bus
+#endif
+#ifndef DEC_DRIVER_ADDRESS
+    #define DEC_DRIVER_ADDRESS 0b10  // MS1=LOW, MS2=HIGH -> address 2
+#endif
+
+// ── AZ axis (Z slot, TMC2209 address 1) ──────────────────────────────────────
+#ifndef AZ_STEP_PIN
+    #define AZ_STEP_PIN 19
+#endif
+#ifndef AZ_DIR_PIN
+    #define AZ_DIR_PIN 28
+#endif
+#ifndef AZ_EN_PIN
+    #define AZ_EN_PIN 2  // Individual EN pin (active LOW)
+#endif
+
+// AZ TMC2209 UART
+#ifndef AZ_SERIAL_PORT
+    #define AZ_SERIAL_PORT Serial2  // Shared UART1 bus
+#endif
+#ifndef AZ_DRIVER_ADDRESS
+    #define AZ_DRIVER_ADDRESS 0b01  // MS1=HIGH, MS2=LOW -> address 1
+#endif
+
+// ── ALT axis (E0 slot, TMC2209 address 3) ────────────────────────────────────
+#ifndef ALT_STEP_PIN
+    #define ALT_STEP_PIN 14
+#endif
+#ifndef ALT_DIR_PIN
+    #define ALT_DIR_PIN 13
+#endif
+#ifndef ALT_EN_PIN
+    #define ALT_EN_PIN 15  // Individual EN pin (active LOW)
+#endif
+
+// ALT TMC2209 UART
+#ifndef ALT_SERIAL_PORT
+    #define ALT_SERIAL_PORT Serial2  // Shared UART1 bus
+#endif
+#ifndef ALT_DRIVER_ADDRESS
+    #define ALT_DRIVER_ADDRESS 0b11  // MS1=HIGH, MS2=HIGH -> address 3
+#endif
+
+// ── UART1 physical pin assignments ───────────────────────────────────────────
+// The SKR Pico routes UART1 to all four on-board TMC2209 ICs via a shared
+// two-wire bus.  GPIO8 and GPIO9 are the native UART1 TX/RX mux functions.
+// b_setup.hpp calls Serial2.setTX()/setRX() before Serial2.begin().
+#ifndef RP2040_UART1_TX_PIN
+    #define RP2040_UART1_TX_PIN 8
+#endif
+#ifndef RP2040_UART1_RX_PIN
+    #define RP2040_UART1_RX_PIN 9
+#endif
+
+// All drivers use hardware UART (Serial2).
+#define SW_SERIAL_UART 0
+
+// ── Debug serial port ─────────────────────────────────────────────────────────
+#ifndef DEBUG_SERIAL_PORT
+    #define DEBUG_SERIAL_PORT Serial  // USB CDC serial via Philhower core
+#endif
+
+// ── GPS (UART0 on left-side header) ──────────────────────────────────────────
+// Left-side 5-pin header: IO0=GPIO0, IO1=GPIO1, GND, 5V.
+// RP2040 pin mux is fixed: GPIO0 = UART0 TX only, GPIO1 = UART0 RX only.
+//   GPS RX → GPIO0 / IO0  (RP2040 UART0 TX)
+//   GPS TX → GPIO1 / IO1  (RP2040 UART0 RX)
+#define GPS_SERIAL_PORT   Serial1
+#define RP2040_GPS_TX_PIN 0  // GPIO0 — UART0 TX → GPS RX
+#define RP2040_GPS_RX_PIN 1  // GPIO1 — UART0 RX ← GPS TX
+
+// ── FAN outputs ───────────────────────────────────────────────────────────────
+// FAN1 connector: switched 12/24V via N-channel MOSFET gated by GPIO17.
+// Power is set via analogWrite (0-100 %). Override RP2040_FAN1_POWER_PERCENT
+// in your local config file to reduce fan speed.
+#define RP2040_FAN1_PIN 17
+#ifndef RP2040_FAN1_POWER_PERCENT
+    #define RP2040_FAN1_POWER_PERCENT 100
+#endif
diff --git a/matrix_build.py b/matrix_build.py
index 8bc80b12..dad16c54 100644
--- a/matrix_build.py
+++ b/matrix_build.py
@@ -25,9 +25,13 @@
 AVR_BOARDS = MKS_GENL_BOARDS + [
     "ramps",
 ]
+RP2040_BOARDS = [
+    "rp2040_jackw01",
+    "rp2040_skr_pico",
+]
 BOARDS = AVR_BOARDS + [
     "esp32",
-]
+] + RP2040_BOARDS
 
 STEPPER_TYPES = [
     "STEPPER_TYPE_NONE",
@@ -176,6 +180,38 @@ def update_dict(orig, patch):
             "DISPLAY_TYPE_LCD_KEYPAD"
         ],
     }),
+    "rp2040_jackw01": update_dict(BUILD_FLAGS, {
+        "USE_GPS": [0],
+        "USE_GYRO_LEVEL": [0],
+        "DISPLAY_TYPE": [
+            "DISPLAY_TYPE_NONE"
+        ],
+        "INFO_DISPLAY_TYPE": [
+            "INFO_DISPLAY_TYPE_NONE"
+        ],
+        "FOCUS_DRIVER_TYPE": [
+            "DRIVER_TYPE_NONE"
+        ],
+        "FOCUS_STEPPER_TYPE": [
+            "STEPPER_TYPE_NONE"
+        ],
+    }),
+    "rp2040_skr_pico": update_dict(BUILD_FLAGS, {
+        "USE_GPS": [0],
+        "USE_GYRO_LEVEL": [0],
+        "DISPLAY_TYPE": [
+            "DISPLAY_TYPE_NONE"
+        ],
+        "INFO_DISPLAY_TYPE": [
+            "INFO_DISPLAY_TYPE_NONE"
+        ],
+        "FOCUS_DRIVER_TYPE": [
+            "DRIVER_TYPE_NONE"
+        ],
+        "FOCUS_STEPPER_TYPE": [
+            "STEPPER_TYPE_NONE"
+        ],
+    }),
 }
 
 SHORT_STRINGS = {
diff --git a/platformio.ini b/platformio.ini
index 8afeb09a..7b68d651 100644
--- a/platformio.ini
+++ b/platformio.ini
@@ -139,6 +139,44 @@ build_flags =
 	-std=gnu++17
 	-D BOARD=BOARD_OAE_V1 -D ESP32BOARD
 
+[common_rp2xxx]
+extends = common_embedded
+; Use maxgerhardt platform wrapper to access Earle Philhower arduino-pico core.
+; The official platform-raspberrypi uses the Arduino-mbed core which has poorer
+; library compatibility and no flexible UART pin remapping.
+platform = https://github.com/maxgerhardt/platform-raspberrypi.git
+board_build.core = earlephilhower
+; SSD1306_128x64_Display.cpp includes SSD1306Wire.h unconditionally at the top of
+; the file (not guarded by INFO_DISPLAY_TYPE), so it can't compile without that
+; library. RP2040 boards don't support this display (ConfigurationValidation.hpp
+; forces INFO_DISPLAY_TYPE_NONE), so exclude the file instead of pulling in an
+; otherwise-unused, possibly RP2040-incompatible dependency.
+src_filter =
+	${common_embedded.src_filter}
+	-<SSD1306_128x64_Display.cpp>
+lib_deps =
+	teemuatlut/TMCStepper @ ^0.7.1
+	waspinator/AccelStepper @ ^1.61
+	mikalhart/TinyGPSPlus @ ^1.0.2
+; TimerInterrupt is AVR-only (uses OCR1A etc.); RP2040 uses hardware/timer.h directly
+lib_ignore = TimerInterrupt
+
+[env:rp2040_jackw01]
+extends = common_rp2xxx
+board = rpipico
+build_flags =
+	${env.build_flags}
+	-Wno-deprecated-declarations  ; arduino-pico core deprecates the B00000000-style Arduino::Binary.h macros used throughout the shared Mount code
+	-D BOARD=BOARD_RP2040_JACKW01
+
+[env:rp2040_skr_pico]
+extends = common_rp2xxx
+board = rpipico
+build_flags =
+	${env.build_flags}
+	-Wno-deprecated-declarations  ; arduino-pico core deprecates the B00000000-style Arduino::Binary.h macros used throughout the shared Mount code
+	-D BOARD=BOARD_RP2040_SKR_PICO
+
 [env:native]
 platform = native
 test_build_src = true
diff --git a/src/EPROMStore.cpp b/src/EPROMStore.cpp
index 5784c177..b4c2108d 100644
--- a/src/EPROMStore.cpp
+++ b/src/EPROMStore.cpp
@@ -84,6 +84,41 @@ uint8_t EEPROMStore::read(uint8_t location)
     return value;
 }
 
+#elif defined(ARDUINO_ARCH_RP2040)
+
+// Initialize the flash-backed EEPROM emulation provided by the Philhower
+// arduino-pico core. API is identical to the ESP32 path.
+void EEPROMStore::initialize()
+{
+    LOG(DEBUG_EEPROM, "[EEPROM]: RP2040: Startup with %d bytes", STORE_SIZE);
+    EEPROM.begin(STORE_SIZE);
+
+    displayContents();
+}
+
+// Update the given location with the given value
+void EEPROMStore::update(uint8_t location, uint8_t value)
+{
+    LOG(DEBUG_EEPROM, "[EEPROM]: RP2040: Writing %x to %d", value, location);
+    EEPROM.write(location, value);
+}
+
+// Complete the transaction (flush RAM cache to flash)
+void EEPROMStore::commit()
+{
+    LOG(DEBUG_EEPROM, "[EEPROM]: RP2040: Committing");
+    EEPROM.commit();
+}
+
+// Read the value at the given location
+uint8_t EEPROMStore::read(uint8_t location)
+{
+    uint8_t value;
+    value = EEPROM.read(location);
+    LOG(DEBUG_EEPROM, "[EEPROM]: RP2040: Read %x from %d", value, location);
+    return value;
+}
+
 #else
 
 // Initialize the EEPROM storage in a platform-independent abstraction
diff --git a/src/InterruptCallback.cpp b/src/InterruptCallback.cpp
index 2a7d5694..18ab6601 100644
--- a/src/InterruptCallback.cpp
+++ b/src/InterruptCallback.cpp
@@ -20,6 +20,11 @@
 PUSH_NO_WARNINGS
         #include "libs/TimerInterrupt/TimerInterrupt.h"
 POP_NO_WARNINGS
+    #elif defined(ARDUINO_ARCH_RP2040)
+        // Earle Philhower arduino-pico core exposes the Pico SDK alarm API.
+        // add_repeating_timer_us() fires a hardware alarm callback at a precise
+        // interval without relying on FreeRTOS or a second core.
+        #include <hardware/timer.h>
     #else
         #error Unrecognized board selected. Either implement interrupt code or define the board here.
     #endif
@@ -47,5 +52,47 @@ void InterruptCallback::start()
     ITimer2.restartTimer();
 }
 
+    #elif defined(ARDUINO_ARCH_RP2040)
+
+// Storage for the repeating timer handle and the user callback+payload.
+static repeating_timer_t _rp2040_timer;
+static interrupt_callback_p _rp2040_callback = nullptr;
+static void *_rp2040_payload                 = nullptr;
+
+// The Pico SDK alarm callback signature returns bool; returning true keeps
+// the timer repeating.
+static bool rp2040_timer_isr(repeating_timer_t * /* rt */)
+{
+    if (_rp2040_callback)
+    {
+        _rp2040_callback(_rp2040_payload);
+    }
+    return true;  // Keep repeating
+}
+
+bool InterruptCallback::setInterval(float intervalMs, interrupt_callback_p callback, void *payload)
+{
+    _rp2040_callback = callback;
+    _rp2040_payload  = payload;
+
+    // Positive delay_us means the period is measured from callback-start to
+    // callback-start (fixed wall-clock rate), which is what the stepper
+    // controller needs for consistent timing.
+    int32_t intervalUs = static_cast<int32_t>(intervalMs * 1000.0f);
+    return add_repeating_timer_us(intervalUs, rp2040_timer_isr, nullptr, &_rp2040_timer);
+}
+
+void InterruptCallback::stop()
+{
+    cancel_repeating_timer(&_rp2040_timer);
+}
+
+void InterruptCallback::start()
+{
+    // Re-arm with the same interval. The stored callback/payload are still set.
+    int32_t intervalUs = static_cast<int32_t>(_rp2040_timer.delay_us);
+    add_repeating_timer_us(intervalUs, rp2040_timer_isr, nullptr, &_rp2040_timer);
+}
+
     #endif
 #endif
\ No newline at end of file
diff --git a/src/Latitude.hpp b/src/Latitude.hpp
index c3ec1591..a3d1f271 100644
--- a/src/Latitude.hpp
+++ b/src/Latitude.hpp
@@ -15,6 +15,7 @@ class Latitude : public core::Latitude
     {
     }
     Latitude(const Latitude &other);
+    Latitude &operator=(const Latitude &) = default;
     Latitude(int h, int m, int s);
     Latitude(float inDegrees);
 
diff --git a/src/Longitude.hpp b/src/Longitude.hpp
index 19661c7f..4c2bd0d0 100644
--- a/src/Longitude.hpp
+++ b/src/Longitude.hpp
@@ -17,6 +17,7 @@ class Longitude : public core::Longitude
     {
     }
     Longitude(const Longitude &other);
+    Longitude &operator=(const Longitude &) = default;
     Longitude(int h, int m, int s);
     Longitude(float inDegrees);
 
diff --git a/src/Mount.cpp b/src/Mount.cpp
index 22911649..20429bd9 100644
--- a/src/Mount.cpp
+++ b/src/Mount.cpp
@@ -498,7 +498,11 @@ void Mount::configureRAdriver(Stream *serial, float rsense, byte driveraddress,
     _driverRA->rms_current(rmscurrent, 1.0f);  //holdMultiplier = 1 to set ihold = irun
     _driverRA->pdn_disable(1);
     _driverRA->ihold(31);
+        #if defined(ARDUINO_ARCH_RP2040)
+    _driverRA->toff(4);  // toff(1) is too short for StealthChop to engage reliably on RP2040
+        #else
     _driverRA->toff(1);
+        #endif
     _driverRA->en_spreadCycle(RA_UART_STEALTH_MODE == 0);
     _driverRA->blank_time(24);
     _driverRA->microsteps(RA_TRACKING_MICROSTEPPING == 1 ? 0 : RA_TRACKING_MICROSTEPPING);  // System starts in tracking mode
@@ -537,7 +541,11 @@ void Mount::configureRAdriver(uint16_t RA_SW_RX, uint16_t RA_SW_TX, float rsense
         #endif
     LOG(DEBUG_STEPPERS, "[MOUNT]: Requested RA motor rms_current: %d mA", rmscurrent);
     _driverRA->rms_current(rmscurrent, 1.0f);  //holdMultiplier = 1 to set ihold = irun
+        #if defined(ARDUINO_ARCH_RP2040)
+    _driverRA->toff(4);  // toff(1) is too short for StealthChop to engage reliably on RP2040
+        #else
     _driverRA->toff(1);
+        #endif
     _driverRA->en_spreadCycle(RA_UART_STEALTH_MODE == 0);
     _driverRA->blank_time(24);
     _driverRA->semin(0);                                                                    //disable CoolStep so that current is consistent
@@ -585,7 +593,11 @@ void Mount::configureDECdriver(Stream *serial, float rsense, byte driveraddress,
     _driverDEC->ihold(31);
     _driverDEC->iholddelay(15);
     _driverDEC->TPOWERDOWN(255);
+        #if defined(ARDUINO_ARCH_RP2040)
+    _driverDEC->toff(4);  // toff(1) is too short for StealthChop to engage reliably on RP2040
+        #else
     _driverDEC->toff(1);
+        #endif
     _driverDEC->en_spreadCycle(DEC_UART_STEALTH_MODE == 0);
     _driverDEC->blank_time(24);
     _driverDEC->microsteps(
@@ -624,7 +636,11 @@ void Mount::configureDECdriver(uint16_t DEC_SW_RX, uint16_t DEC_SW_TX, float rse
         #endif
     LOG(DEBUG_STEPPERS, "[MOUNT]: Requested DEC motor rms_current: %d mA", rmscurrent);
     _driverDEC->rms_current(rmscurrent, 1.0f);  //holdMultiplier = 1 to set ihold = irun
+        #if defined(ARDUINO_ARCH_RP2040)
+    _driverDEC->toff(4);  // toff(1) is too short for StealthChop to engage reliably on RP2040
+        #else
     _driverDEC->toff(1);
+        #endif
     _driverDEC->en_spreadCycle(DEC_UART_STEALTH_MODE == 0);
     _driverDEC->blank_time(24);
     _driverDEC->microsteps(
@@ -668,7 +684,11 @@ void Mount::configureAZdriver(Stream *serial, float rsense, byte driveraddress,
         #endif
     LOG(DEBUG_STEPPERS, "[MOUNT]: Requested AZ motor rms_current: %d mA", rmscurrent);
     _driverAZ->rms_current(rmscurrent, AZ_MOTOR_HOLD_SETTING / 100.0);  //holdMultiplier = 1 to set ihold = irun
+        #if defined(ARDUINO_ARCH_RP2040)
+    _driverAZ->toff(4);  // toff(1) is too short for StealthChop to engage reliably on RP2040
+        #else
     _driverAZ->toff(1);
+        #endif
     _driverAZ->en_spreadCycle(0);
     _driverAZ->blank_time(24);
     _driverAZ->microsteps(AZ_MICROSTEPPING == 1 ? 0 : AZ_MICROSTEPPING);  // If 1 then disable microstepping
@@ -706,7 +726,11 @@ void Mount::configureAZdriver(uint16_t AZ_SW_RX, uint16_t AZ_SW_TX, float rsense
         #endif
     LOG(DEBUG_STEPPERS, "[MOUNT]: Requested AZ motor rms_current: %d mA", rmscurrent);
     _driverAZ->rms_current(rmscurrent, AZ_MOTOR_HOLD_SETTING / 100.0);  //holdMultiplier = 1 to set ihold = irun
+        #if defined(ARDUINO_ARCH_RP2040)
+    _driverAZ->toff(4);  // toff(1) is too short for StealthChop to engage reliably on RP2040
+        #else
     _driverAZ->toff(1);
+        #endif
     _driverAZ->en_spreadCycle(0);
     _driverAZ->blank_time(24);
     _driverAZ->microsteps(AZ_MICROSTEPPING == 1 ? 0 : AZ_MICROSTEPPING);  // If 1 then disable microstepping
@@ -749,7 +773,11 @@ void Mount::configureALTdriver(Stream *serial, float rsense, byte driveraddress,
         #endif
     LOG(DEBUG_STEPPERS, "[MOUNT]: Requested ALT motor rms_current: %d mA", rmscurrent);
     _driverALT->rms_current(rmscurrent, ALT_MOTOR_HOLD_SETTING / 100.0);  //holdMultiplier = 1 to set ihold = irun
+        #if defined(ARDUINO_ARCH_RP2040)
+    _driverALT->toff(4);  // toff(1) is too short for StealthChop to engage reliably on RP2040
+        #else
     _driverALT->toff(1);
+        #endif
     _driverALT->en_spreadCycle(0);
     _driverALT->blank_time(24);
     _driverALT->microsteps(ALT_MICROSTEPPING == 1 ? 0 : ALT_MICROSTEPPING);  // If 1 then disable microstepping
@@ -787,7 +815,11 @@ void Mount::configureALTdriver(uint16_t ALT_SW_RX, uint16_t ALT_SW_TX, float rse
         #endif
     LOG(DEBUG_STEPPERS, "[MOUNT]: Requested ALT motor rms_current: %d mA", rmscurrent);
     _driverALT->rms_current(rmscurrent, ALT_MOTOR_HOLD_SETTING / 100.0);  //holdMultiplier = 1 to set ihold = irun
+        #if defined(ARDUINO_ARCH_RP2040)
+    _driverALT->toff(4);  // toff(1) is too short for StealthChop to engage reliably on RP2040
+        #else
     _driverALT->toff(1);
+        #endif
     _driverALT->en_spreadCycle(0);
     _driverALT->blank_time(24);
     _driverALT->microsteps(ALT_MICROSTEPPING == 1 ? 0 : ALT_MICROSTEPPING);  // If 1 then disable microstepping
@@ -832,7 +864,11 @@ void Mount::configureFocusDriver(Stream *serial, float rsense, byte driveraddres
         #endif
     LOG(DEBUG_STEPPERS | DEBUG_FOCUS, "[FOCUS]: Requested Focus motor rms_current: %d mA", rmscurrent);
     _driverFocus->rms_current(rmscurrent, FOCUSER_MOTOR_HOLD_SETTING / 100.f);  //holdMultiplier = 1 to set ihold = irun
+        #if defined(ARDUINO_ARCH_RP2040)
+    _driverFocus->toff(4);  // toff(1) is too short for StealthChop to engage reliably on RP2040
+        #else
     _driverFocus->toff(1);
+        #endif
     _driverFocus->en_spreadCycle(FOCUS_UART_STEALTH_MODE == 0);
     _driverFocus->blank_time(24);
     _driverFocus->microsteps(FOCUS_MICROSTEPPING == 1 ? 0 : FOCUS_MICROSTEPPING);  // If 1 then disable microstepping
@@ -878,7 +914,11 @@ void Mount::configureFocusDriver(
         #endif
     LOG(DEBUG_STEPPERS | DEBUG_FOCUS, "[FOCUS]: Requested Focus motor rms_current: %d mA", rmscurrent);
     _driverFocus->rms_current(rmscurrent, FOCUSER_MOTOR_HOLD_SETTING / 100.f);  //holdMultiplier = 1 to set ihold = irun
+        #if defined(ARDUINO_ARCH_RP2040)
+    _driverFocus->toff(4);  // toff(1) is too short for StealthChop to engage reliably on RP2040
+        #else
     _driverFocus->toff(1);
+        #endif
     _driverFocus->en_spreadCycle(FOCUS_UART_STEALTH_MODE == 0);
     _driverFocus->blank_time(24);
     _driverFocus->microsteps(FOCUS_MICROSTEPPING == 1 ? 0 : FOCUS_MICROSTEPPING);  // If 1 then disable microstepping
diff --git a/src/b_setup.hpp b/src/b_setup.hpp
index 76f10786..2b2c21c0 100644
--- a/src/b_setup.hpp
+++ b/src/b_setup.hpp
@@ -126,9 +126,28 @@ void setup()
     #endif
 #else
     Serial.begin(SERIAL_BAUDRATE);
+    #if defined(ARDUINO_ARCH_RP2040)
+    // OATControl (and other apps using C# SerialPort) open the port with DTR=false.
+    // The Philhower USB CDC SerialUSB::write() gates TX on tud_cdc_connected() which
+    // requires DTR=true, so all responses are silently dropped for those hosts.
+    // ignoreFlowControl(true) bypasses the DTR check and always sends TX data.
+    Serial.ignoreFlowControl(true);
+    #endif
     #if DEBUG_LEVEL > 0 && DEBUG_SEPARATE_SERIAL == 1
     DEBUG_SERIAL_PORT.begin(DEBUG_SERIAL_BAUDRATE);
     #endif
+    // RP2040 USB CDC: wait up to 3 s for the host to open the port so that
+    // LOG() calls below are not dropped (or do not block indefinitely).
+    // This only matters when DEBUG_LEVEL > 0 — in release builds LOG() is
+    // a no-op, so the wait is compiled out.
+    #if defined(ARDUINO_ARCH_RP2040) && DEBUG_LEVEL > 0
+    {
+        uint32_t _cdcWaitStart = millis();
+        while (!Serial && (millis() - _cdcWaitStart) < 3000UL)
+        { /* spin */
+        }
+    }
+    #endif
 #endif
 
 #if TEST_VERIFY_MODE == 1
@@ -161,6 +180,10 @@ void setup()
     #if (INFO_DISPLAY_TYPE != INFO_DISPLAY_TYPE_NONE)
     int gpsLine = addConsoleText(F("Initialize GPS..."));
     #endif
+    #if defined(ARDUINO_ARCH_RP2040) && defined(RP2040_GPS_TX_PIN) && defined(RP2040_GPS_RX_PIN)
+    GPS_SERIAL_PORT.setTX(RP2040_GPS_TX_PIN);
+    GPS_SERIAL_PORT.setRX(RP2040_GPS_RX_PIN);
+    #endif
     GPS_SERIAL_PORT.begin(GPS_BAUD_RATE);
     #if (INFO_DISPLAY_TYPE != INFO_DISPLAY_TYPE_NONE)
     updateConsoleText(gpsLine, F("Initialize GPS... OK"));
@@ -180,6 +203,11 @@ void setup()
     updateConsoleText(dewHeaterLine, F("Enable Dew Heater... OK"));
 #endif
 
+#if defined(RP2040_FAN1_PIN)
+    pinMode(RP2040_FAN1_PIN, OUTPUT);
+    analogWrite(RP2040_FAN1_PIN, (RP2040_FAN1_POWER_PERCENT * 255) / 100);
+#endif
+
 #if (USE_RA_END_SWITCH == 1 || USE_DEC_END_SWITCH == 1)
     int endSwitchesLine = addConsoleText(F("Init End Switches..."));
     LOG(DEBUG_ANY, "[SYSTEM]: Init EndSwitches...");
@@ -187,6 +215,21 @@ void setup()
     updateConsoleText(endSwitchesLine, F("Init End Switches... OK"));
 #endif
 
+    /////////////////////////////////
+    //   RP2040: UART pin remapping
+    /////////////////////////////////
+    // The Philhower arduino-pico core requires setTX()/setRX() to be called
+    // before begin() to remap UART pins away from their defaults. This must
+    // happen before any Serial2.begin() calls in the driver setup below.
+    // RP2040_UART1_TX_PIN / RP2040_UART1_RX_PIN are defined in the board's
+    // pins file only for RP2040 targets that use a non-default UART1 mapping.
+#if defined(ARDUINO_ARCH_RP2040) && defined(RP2040_UART1_TX_PIN) && defined(RP2040_UART1_RX_PIN)
+    Serial2.setTX(RP2040_UART1_TX_PIN);
+    Serial2.setRX(RP2040_UART1_RX_PIN);
+    Serial2.setPollingMode(true);  // Must be called before begin(); avoids IRQ/CoreMutex blocking in TMCStepper read path
+    Serial2.begin(115200);         // TMCStepper HW-serial path never calls begin(); must do it here.
+#endif
+
     /////////////////////////////////
     //   Microstepping/driver pins
     /////////////////////////////////
@@ -213,7 +256,9 @@ void setup()
     #endif
 
     #ifdef RA_SERIAL_PORT
-        #ifdef OAE
+        #if defined(ARDUINO_ARCH_RP2040)
+    RA_SERIAL_PORT.begin(115200);  // TMCStepper requires 115200 baud on the Philhower RP2040 core
+        #elif defined(OAE)
     RA_SERIAL_PORT.begin(57600, SERIAL_8N1, RA_RX_PIN, RA_TX_PIN);
         #else
     RA_SERIAL_PORT.begin(57600);  // Start HardwareSerial comms with driver
@@ -246,7 +291,9 @@ void setup()
     pinMode(DEC_DIAG_PIN, INPUT);
     #endif
     #ifdef DEC_SERIAL_PORT
-        #ifdef OAE
+        #if defined(ARDUINO_ARCH_RP2040)
+    DEC_SERIAL_PORT.begin(115200);  // TMCStepper requires 115200 baud on the Philhower RP2040 core
+        #elif defined(OAE)
     DEC_SERIAL_PORT.begin(57600, SERIAL_8N1, DEC_RX_PIN, DEC_TX_PIN);
         #else
     DEC_SERIAL_PORT.begin(57600);  // Start HardwareSerial comms with driver
@@ -262,10 +309,16 @@ void setup()
     pinMode(AZ_EN_PIN, OUTPUT);
     digitalWrite(AZ_EN_PIN, HIGH);  // Logic HIGH to disable the driver initally
     #if AZ_DRIVER_TYPE == DRIVER_TYPE_TMC2209_UART
-    // include TMC2209 UART pins
+        // include TMC2209 UART pins
+        #if defined(AZ_DIAG_PIN)
     pinMode(AZ_DIAG_PIN, INPUT);
+        #endif
         #ifdef AZ_SERIAL_PORT
+            #if defined(ARDUINO_ARCH_RP2040)
+    AZ_SERIAL_PORT.begin(115200);  // TMCStepper requires 115200 baud on the Philhower RP2040 core
+            #else
     AZ_SERIAL_PORT.begin(57600);  // Start HardwareSerial comms with driver
+            #endif
         #endif
     #endif
     updateConsoleText(azLine, F("Init AZ axis... OK"));
@@ -277,10 +330,16 @@ void setup()
     pinMode(ALT_EN_PIN, OUTPUT);
     digitalWrite(ALT_EN_PIN, HIGH);  // Logic HIGH to disable the driver initally
     #if ALT_DRIVER_TYPE == DRIVER_TYPE_TMC2209_UART
-    // include TMC2209 UART pins
+        // include TMC2209 UART pins
+        #if defined(ALT_DIAG_PIN)
     pinMode(ALT_DIAG_PIN, INPUT);
+        #endif
         #ifdef ALT_SERIAL_PORT
+            #if defined(ARDUINO_ARCH_RP2040)
+    ALT_SERIAL_PORT.begin(115200);  // TMCStepper requires 115200 baud on the Philhower RP2040 core
+            #else
     ALT_SERIAL_PORT.begin(57600);  // Start HardwareSerial comms with driver
+            #endif
         #endif
     #endif
     updateConsoleText(altLine, F("Init ALT axis... OK"));
@@ -295,11 +354,25 @@ void setup()
         // include TMC2209 UART pins
         #ifdef FOCUS_SERIAL_PORT
     LOG(DEBUG_FOCUS, "[FOCUS]: setup(): focus TMC2209U starting comms");
+            #if defined(ARDUINO_ARCH_RP2040)
+    FOCUS_SERIAL_PORT.begin(115200);  // TMCStepper requires 115200 baud on the Philhower RP2040 core
+            #else
     FOCUS_SERIAL_PORT.begin(57600);  // Start HardwareSerial comms with driver
+            #endif
         #endif
     #endif
     updateConsoleText(focusLine, F("Init Focuser... OK"));
 #endif
+
+#if defined(RP2040_SHARED_EN_PIN)
+    // On boards where all stepper EN lines share one GPIO (e.g. JackW01 carrier),
+    // the per-axis init sequence leaves that GPIO HIGH (logic disabled) after the
+    // AZ/ALT blocks run.  Force it LOW here so every driver is enabled once all
+    // UART addresses have been configured.  Per-axis power management is handled
+    // via the TMC2209 IHOLD register over UART rather than toggling this pin.
+    pinMode(RP2040_SHARED_EN_PIN, OUTPUT);
+    digitalWrite(RP2040_SHARED_EN_PIN, LOW);
+#endif
     // end microstepping -------------------
 
 #if USE_HALL_SENSOR_RA_AUTOHOME == 1 || USE_HALL_SENSOR_DEC_AUTOHOME == 1
@@ -535,6 +608,15 @@ void setup()
     #endif
 #endif
 
+#if defined(RP2040_SHARED_EN_PIN)
+    // Re-assert EN LOW after all driver configs.  Each configureXXXdriver() that
+    // fails its UART connection test calls digitalWrite(X_EN_PIN, HIGH) as a
+    // safety measure; on JackW01 all EN lines share one GPIO so all four failures
+    // leave that GPIO HIGH (motors disabled).  Override it here unconditionally so
+    // the motors are always enabled after initialization.
+    digitalWrite(RP2040_SHARED_EN_PIN, LOW);
+#endif
+
     LOG(DEBUG_ANY, "[SYSTEM]: Energize Steppers... OK");
     updateConsoleText(stepperLine, F("Energize Steppers... OK"));
 
diff --git a/src/c_buttons.hpp b/src/c_buttons.hpp
index d594cb2c..c1c3a321 100644
--- a/src/c_buttons.hpp
+++ b/src/c_buttons.hpp
@@ -98,6 +98,13 @@ void loop()
     lcdMenu.setCursor(0, 1);
 
     #if SUPPORT_SERIAL_CONTROL == 1
+        #if defined(ARDUINO_ARCH_RP2040)
+    // On RP2040, the Philhower core does not reliably call serialEvent() for the
+    // USB CDC Serial port when a host application opens the port and immediately
+    // sends data (e.g. OATControl). Poll explicitly on every loop() iteration so
+    // that commands are always processed regardless of inSerialControl state.
+    processSerialData();
+        #endif
     if (inSerialControl)
     {
         if (lcdButtons.keyChanged(&lcd_key))
diff --git a/src/core/types/DayTime.hpp b/src/core/types/DayTime.hpp
index 98c0638d..7ab5c3ca 100644
--- a/src/core/types/DayTime.hpp
+++ b/src/core/types/DayTime.hpp
@@ -18,6 +18,7 @@ class DayTime
     DayTime();
 
     DayTime(const DayTime &other);
+    DayTime &operator=(const DayTime &) = default;
     DayTime(int h, int m, int s);
 
     // From hours (fractional)
diff --git a/src/core/types/Declination.hpp b/src/core/types/Declination.hpp
index de65d3e9..ca3185d5 100644
--- a/src/core/types/Declination.hpp
+++ b/src/core/types/Declination.hpp
@@ -15,6 +15,7 @@ class Declination : public DayTime
   public:
     Declination();
     Declination(const Declination &other);
+    Declination &operator=(const Declination &) = default;
     Declination(int h, int m, int s);
     Declination(float inDegrees);
 
diff --git a/src/core/types/Latitude.hpp b/src/core/types/Latitude.hpp
index 168587ce..feb382b5 100644
--- a/src/core/types/Latitude.hpp
+++ b/src/core/types/Latitude.hpp
@@ -12,6 +12,7 @@ class Latitude : public DayTime
   public:
     Latitude();
     Latitude(const Latitude &other);
+    Latitude &operator=(const Latitude &) = default;
     Latitude(int h, int m, int s);
     Latitude(float inDegrees);
 
diff --git a/src/core/types/Longitude.hpp b/src/core/types/Longitude.hpp
index 6c52e44e..f9722c1c 100644
--- a/src/core/types/Longitude.hpp
+++ b/src/core/types/Longitude.hpp
@@ -12,6 +12,7 @@ class Longitude : public DayTime
   public:
     Longitude();
     Longitude(const Longitude &other);
+    Longitude &operator=(const Longitude &) = default;
     Longitude(int h, int m, int s);
     Longitude(float inDegrees);