QUERY · ISSUE

esp32/machine_pin: ESP32-P4 pin 54 can't be set to output

openby sfe-SparkFroopened 2026-03-23updated 2026-03-23

bugport-esp32

Port, board and/or hardware

esp32 port, generic ESP32-P4 board

MicroPython version

MicroPython v1.27.0 on 2025-12-09; Generic ESP32P4 module with ESP32P4

Reproduction

MicroPython v1.27.0 on 2025-12-09; Generic ESP32P4 module with ESP32P4
Type "help()" for more information.
>>> import machine
>>> machine.Pin(53, machine.Pin.OUT)
Pin(53)
>>> machine.Pin(54, machine.Pin.OUT)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
ValueError: pin can only be input

Expected behaviour

machine.Pin(54, machine.Pin.OUT) should work, because all GPIO pins on the ESP32-P4 are output capable.

Observed behaviour

machine.Pin(54, machine.Pin.OUT) states pin can only be input, which is false.

Additional Information

No, I've provided everything above.

Code of Conduct

Yes, I agree

CANDIDATE · PULL REQUEST

drivers/ninaw10: Fix ESP input only pins.

mergedby iabdalkaderopened 2023-03-26updated 2023-04-04

drivers

ESP pins 34, 35, 36 and 39 are input only, and should not be configured as output.

Assessment

S Sonnet · high

Both items involve GPIO pin input/output capability validation in MicroPython ESP-related code, but they are distinct issues in different drivers and address opposite problems. PR #11129 is in drivers/ninaw10/machine_pin_nina.c and correctly adds input-only restrictions for pins 34, 35, 36, 39 that are genuinely hardware-constrained on the NINA W10 module. Issue #18982 is about esp32/machine_pin.c (the main ESP32 port) where pin 54 on ESP32-P4 is incorrectly flagged as input-only when it is actually output-capable — a false positive in the opposite direction. The candidate PR does not touch the ESP32-P4 pin table, does not reference pin 54, and was merged well before the ESP32-P4 was supported. It provides no fix for the query.

Suggested action

No action needed between these items. The query (issue #18982) requires a separate fix: auditing the ESP32-P4 pin capability table in `esp32/machine_pin.c` (or its board-specific data) to correct the input-only flag for pin 54. PR #11129 can serve as a reference for how input-only validation is structured in the codebase but does not resolve the bug.