rp2040link

rp2040link is a high-level, polarity-aware Python controller for Raspberry Pi Pico / RP2040 boards from a host computer.

It is designed for the workflow you described:

• Flash a resident firmware to the Pico (a “server” that stays online),
• Then control the Pico’s pins from the PC with a clean Python API over USB serial.

Powered by: rp2040link builds on the proven Telemetrix-RPi-Pico stack (host-side Python + Pico-side firmware) and provides a more ergonomic, modern, and safer API layer on top.

Why rp2040link?

Telemetrix is excellent, but you often want a more “application-shaped” interface:

• Per-pin polarity (active-low vs active-high) without stringly-typed APIs
• Safe startup (force outputs to a known OFF state)
• Binary/bitmask writing to 1 pin or a pin bus
• Convenience helpers: blink, pulse, groups, sync I2C/SPI reads, etc.

rp2040link is exactly that: a thin, ergonomic layer over Telemetrix.

Requirements

• Python 3.9+
• A Raspberry Pi Pico / RP2040 board
• Telemetrix Pico firmware flashed (UF2)
• USB data cable

Install

pip install rp2040link

Flash the Pico (Telemetrix UF2)

Telemetrix requires a small Pico “server” firmware (UF2). Steps (high-level):

1. Hold BOOTSEL while plugging the Pico into USB (it appears as a drive like RPI-RP2).
2. Drag & drop the Telemetrix UF2 onto the drive.
3. The board reboots and should appear as a serial device (Linux: /dev/ttyACM*, macOS: /dev/cu.*, Windows: COM port).

If you are unsure which UF2 to use, check Telemetrix-RPi-Pico documentation for the current UF2 builds.

Quick Start

Mixed polarity outputs (the style you asked for)

import time
from rp2040link import Pico

GP14, GP15 = 14, 15

with Pico() as pico:
    pico.setup_output.active_low(GP14, initial_off=True)    # ON=0 OFF=1
    pico.setup_output.active_high(GP15, initial_off=True)   # ON=1 OFF=0

    pico.gpio.on(GP14); time.sleep(0.5); pico.gpio.off(GP14)
    pico.gpio.on(GP15); time.sleep(0.5); pico.gpio.off(GP15)

    pico.gpio.blink([GP14, GP15], times=20, period_s=0.2)

Binary helpers (single pin + bus)

Single pin (very simple)

from rp2040link import Pico
import time

with Pico() as pico:
    pico.setup_output.active_low(14, initial_off=True)

    b = pico.binary.pin(14)
    b.bit(1); time.sleep(0.2)
    b.bit(0); time.sleep(0.2)
    b.pattern("101001", delay_s=0.05)

Bus (bitmask write)

from rp2040link import Pico
import time

with Pico() as pico:
    pico.setup_output.active_low(14, initial_off=True)
    pico.setup_output.active_high(15, initial_off=True)

    bus = pico.binary.pins(14, 15)  # msb_first=True by default
    bus.write(0b10); time.sleep(0.3)
    bus.write(0b01); time.sleep(0.3)
    bus.stream([0,1,2,3,2,1,0], delay_s=0.15)

CLI

rp2040link ships with a small CLI for quick checks:

rp2040link ports
rp2040link blink --pins 14,15 --polarity 14:low,15:high --times 20 --period 0.2

Troubleshooting

“No such file or directory: /dev/ttyACM0”

• The Pico is likely still in BOOTSEL mode (shows as RPI-RP2 drive) OR
• The cable is charge-only (no data) OR
• The port is not /dev/ttyACM0 (use rp2040link ports).

Permission denied (Linux)

Add your user to dialout and re-login:

sudo usermod -aG dialout $USER

Project layout

• src/rp2040link/ : library code
• examples/ : runnable examples
• tests/ : unit tests (hardware-free)
• docs/ : docs assets

Development

pip install -e ".[dev]"
pytest

Build distributions:

python -m build

License

MIT — see LICENSE.

Publishing

See PUBLISHING.md for step-by-step instructions (Trusted Publishing via GitHub OIDC or manual Twine upload).

Without with (manual connect/close)

from rp2040link import Pico
import time

pico = Pico()
try:
    pico.open()  # or pico.connect()

    pico.setup_output.active_low(14, initial_off=True)
    pico.gpio.on(14); time.sleep(1); pico.gpio.off(14)
finally:
    pico.close()  # or pico.disconnect()

Auto-connect options

• Pico(auto_open=True) connects in __post_init__.
• Pico(lazy_open=True) connects automatically on first access to .board.

pico = Pico(auto_open=True)     # connects immediately
# or:
pico = Pico(lazy_open=True)     # connects on first operation that touches `.board`