Add RP2040 Support for JackW01 and BTT SKR Pico boards by EricSchubert · Pull Request #280 · OpenAstroTech/OpenAstroTracker-Firmware

EricSchubert · 2026-03-10T06:39:43Z

Utilized Claude AI to add hardware support for RP2040-based BigTreeTech SKR Pico v1.0 and open-source JackW01 Pico printer boards. (GitHub for JackW01 here: https://jackw01.github.io/pi-pico-printer-board/ )

NOTE: This also requires modification to TMCStepper2208 library, found on my GitHub page:
https://github.com/EricSchubert/TMCStepper-RP2040_Support

libdeps has been updated in platformio.ini to point to this repo until official TMCStepper code merges the changes.

Add RP2040 support for JackW01 Pi Pico Printer Board and BTT SKR Pico v1.0

Summary

This PR adds firmware support for two RP2040-based boards, both using TMC2209 drivers
via UART and the Earle Philhower RP2040 Arduino core.

Supported boards (both confirmed working on hardware):

env:rp2040_jackw01 — JackW01 Pi Pico Printer Board
env:rp2040_skr_pico — BigTreeTech SKR Pico v1.0

Changes

New files:

boards/RP2040_SKR_PICO/pins_RP2040_SKR_PICO.hpp — GPIO assignments for SKR Pico
Configuration_local_examples/Configuration_local_rp2040_skr_pico.hpp — example config for SKR Pico

Modified files:

platformio.ini — added rp2040_jackw01 and rp2040_skr_pico environments
Constants.hpp — added BOARD_RP2040_SKR_PICO
Configuration.hpp — added SKR Pico pins include
LocalConfiguration.hpp — added SKR Pico branch
ConfigurationValidation.hpp — added RP2040 to GPS whitelist
src/Mount.cpp — set toff(4) on all drivers (required for StealthChop on RP2040);
UART_CONNECTION_TEST_RETRIES = 5

TMC2209 UART patch

The stock TMCStepper library does not support the Philhower RP2040 core's single-wire
half-duplex UART model. A patch to TMC2208Stepper.cpp adds an
_rp2040_sw_uart_write_byte code path. platformio.ini references a patched fork of
TMCStepper via lib_deps — no manual steps required.

OATControl compatibility fix

SerialUSB::write() on the Philhower core gates transmission on host DTR. Most serial
clients (including OATControl's C# SerialPort) default to DtrEnable=false, silently
dropping all firmware responses. Fix: Serial.ignoreFlowControl(true) after
Serial.begin(), guarded by #if defined(ARDUINO_ARCH_RP2040) in src/b_setup.hpp.

Tested on hardware

UART communication confirmed on all 4 TMC2209 drivers
StealthChop confirmed working
RA Hall sensor homing confirmed from both directions
OATControl connects and controls mount via direct serial (COM port)
GPS (ATGM336H-5N) confirmed working on SKR Pico
DEC direction correct on both boards

openastrotech-bot · 2026-03-10T06:40:03Z

Looks like your PR has code that needs to be changed in order to meet our coding standards!
Here are your options:

Apply the patch that was generated by the job
1. Click details under the failing clang-format check
2. Click the Artifacts dropdown in the top right
3. Download + unzip the clang-format-diff.patch file into the OpenAstroTracker-Firmware repo
4. Run git apply clang-format-diff.patch to make the changes
5. Commit and push up the formatted code
Run clang-format locally
1. Run the command bash -c 'shopt -s nullglob globstar;GLOBIGNORE=./src/libs/TimerInterrupt/*; for i in ./{.,src/**,unit_tests,boards/**}/*.{c,cpp,h,hpp}; do clang-format -i $i; done'
2. Commit and push up the formatted code

EricSchubert · 2026-03-10T14:51:51Z

I'm attaching a file created by Claude AI to explain the any code changes made to support RP2040 and the BTT SKR Pico.
RP2040_PORT_NOTES.md

julianneswinoga · 2026-03-14T18:07:33Z

Configuration.hpp

-    #ifndef INFO_DISPLAY_UPSIDE_DOWN
-        #define INFO_DISPLAY_UPSIDE_DOWN 0
-    #endif
-    #ifndef INFO_DISPLAY_MIRRORED
-        #define INFO_DISPLAY_MIRRORED 0
-    #endif


Why remove these?

Not sure why these were removed. It was not intentional. Likely Claude removed them because I didn't need a display for my build.

julianneswinoga · 2026-03-14T18:08:11Z

Configuration.hpp

+#elif (BOARD == BOARD_RP2040_JACKW01) || (BOARD == BOARD_RP2350_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"


these files don't exist

The file pins_RP2040_SKR_PICO.hpp does exist in this branch. I can supply the pins_RP2040_JACKW01.hpp file. This was left out by mistake and should have been included.

julianneswinoga · 2026-03-14T18:09:13Z

ConfigurationValidation.hpp

        #endif
    #elif (AZ_DRIVER_TYPE == DRIVER_TYPE_TMC2209_UART)
        #if !defined(AZ_STEP_PIN) || !defined(AZ_DIR_PIN) || !defined(AZ_EN_PIN)
-            // Required pin assignments missing (ATmega uses SoftwareSerial for this driver)


Don't remove the comment

julianneswinoga · 2026-03-14T18:09:31Z

ConfigurationValidation.hpp

        #endif
    #endif

-#elif defined(OAE)


Don't remove these

julianneswinoga · 2026-03-14T18:10:09Z

Constants.hpp

+// RP2040/RP2350 based boards (2000-2999)
+//   2001-2099: Generic bare Pico family (user-defined wiring) -- NOT YET SUPPORTED
+//   2101-2199: Pico family + JackW01 printer carrier board
+//   2201-2299: BTT SKR Pico family
+// #define BOARD_RP2040_PICO      2001  // NOT YET SUPPORTED: requires user-defined pin wiring in local config
+// #define BOARD_RP2350_PICO2     2002  // NOT YET SUPPORTED: requires user-defined pin wiring in local config
+#define BOARD_RP2040_JACKW01   2101  // Raspberry Pi Pico (RP2040) + JackW01 printer board
+#define BOARD_RP2350_JACKW01   2102  // Raspberry Pi Pico 2 (RP2350) + JackW01 printer board


Don't add references to boards that don't exist

julianneswinoga · 2026-03-14T18:12:29Z

platformio.ini

 	arduino-libraries/LiquidCrystal @ ^1.0.7
 	lincomatic/LiquidTWI2@^1.2.7
 	olikraus/U8g2@^2.28.8
-	https://github.com/ClutchplateDude/esp8266-oled-ssd1306#4.6.2


Don't change this

julianneswinoga · 2026-03-14T18:13:21Z

platformio.ini

 	${common.lib_deps}
 	jdolinay/avr-debugger @ 1.2
-	https://github.com/andre-stefanov/avr-interrupt-stepper#0.0.4
+	https://github.com/andre-stefanov/avr-interrupt-stepper@0.0.4


Incorrect library specification: https://docs.platformio.org/en/latest/core/userguide/pkg/cmd_install.html#repository-git-hg-svn

…AstroTracker-Firmware-RP2040 into RP2040-Support

EricSchubert · 2026-03-15T05:04:13Z

@julianneswinoga, I believe all requested changes have been addressed. Ready for re-review.

julianneswinoga · 2026-03-15T16:10:21Z

ConfigurationValidation.hpp

        #endif
    #elif (ALT_DRIVER_TYPE == DRIVER_TYPE_TMC2209_UART)
        #if !defined(ALT_STEP_PIN) || !defined(ALT_DIR_PIN) || !defined(ALT_EN_PIN)
-            // Required pin assignments missing (ATmega uses SoftwareSerial for this driver)


don't remove this comment

julianneswinoga · 2026-03-15T16:17:36Z

src/Mount.cpp

+// slewingStatus()
+#define SLEWING_DEC      0b00000010
+#define SLEWING_RA       0b00000001
+#define SLEWING_BOTH     0b00000011
+#define SLEWING_TRACKING 0b00001000
+#define NOT_SLEWING      0b00000000
+
+// slewStatus
+#define SLEW_MASK_DEC   0b0011
+#define SLEW_MASK_NORTH 0b0001
+#define SLEW_MASK_SOUTH 0b0010
+#define SLEW_MASK_RA    0b1100
+#define SLEW_MASK_EAST  0b0100
+#define SLEW_MASK_WEST  0b1000
+#define SLEW_MASK_ANY   0b1111


Do not change the format of these

julianneswinoga · 2026-03-15T16:18:52Z

src/Mount.cpp

There's a lot of changes here not relevant to the pico, please revert.

Eric Schubert and others added 2 commits March 10, 2026 00:12

Add RP2040 Support for JackW01 and BTT SKR Pico boards

25dae05

Update platformio.ini

72fc46b

julianneswinoga requested changes Mar 14, 2026

View reviewed changes

Eric Schubert added 3 commits March 14, 2026 22:17

Add pins file for JackW01 Pi Pico Printer Board

0b7b6d1

Merge branch 'RP2040-Support' of https://github.com/EricSchubert/Open…

2cdf29a

…AstroTracker-Firmware-RP2040 into RP2040-Support

Address PR review feedback

275fe74

julianneswinoga requested changes Mar 15, 2026

View reviewed changes

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EricSchubert commented Mar 10, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

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Add RP2040 support for JackW01 Pi Pico Printer Board and BTT SKR Pico v1.0

Summary

Changes

TMC2209 UART patch

OATControl compatibility fix

Tested on hardware

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openastrotech-bot commented Mar 10, 2026

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EricSchubert commented Mar 10, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

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EricSchubert commented Mar 15, 2026

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EricSchubert commented Mar 10, 2026 •

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EricSchubert commented Mar 10, 2026 •

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