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Assembly & Flashing

Getting a working Pico de Gallo on your desk takes two steps:

  1. Get a populated PCB.
  2. Flash the firmware.

Step 1 has three options, ordered from easiest to most hands-on. Step 2 is the same regardless of how you got the board.

Step 1: Get a Populated PCB

Option A — Have the PCB house assemble it

Most modern PCB fabrication services (JLCPCB, PCBWay, OSH Park with their assembly partners, Aisler, etc.) will both fabricate and assemble the board for you. Upload the gerbers, BOM, and pick-and-place files from the hardware-v* release, choose your solder mask color, and a fully-built board arrives at your door. This is the recommended path — it’s cheap at small quantities, and your time is worth more than the assembly fee.

Note

Pico de Gallo PCB assembly is not affiliated with any specific PCB house. Any cost, mistake, or damage associated with PCB fabrication and assembly is your responsibility.

Option B — Fabricate bare, solder yourself

If you’d rather solder, the board uses through-hole and medium-pitch components only — there’s nothing exotic.

Order of operations:

  1. Solder the Pico 2 first. It’s the lowest component on the board. Tack one corner pad, check alignment, tack the opposite corner, then run a bead along all remaining pads. A bit of no-clean flux makes this much easier — solder follows flux onto exposed copper.
  2. Right-angle headers next. Hold them in place with a piece of polyimide (“Kapton”) tape or a third hand, tack one pin, verify the header sits flush, then solder the rest.
  3. Straight headers last. Same approach — one pin first, check alignment, finish the rest.
  4. Clean off the flux with 99% IPA and an ESD-safe brush in a well-ventilated area.

Caution

Isopropyl alcohol is flammable. Don’t smoke or have open flames near it. Use it in a well-ventilated area.

After cleanup, eyeball the board for solder bridges between adjacent pins before applying USB power.

Option C — Skip the PCB, wire a bare Pico 2

The firmware works on a bare Pico 2 too. Wire your peripherals directly to the RP2350 GPIOs listed in Pinout & Connector. You’ll need to provide your own I²C pull-ups (4.7 kΩ to 3.3 V on SDA and SCL) if you want I²C to work.

Step 2: Flash the Firmware

The Pico 2 ships with a built-in UF2 bootloader, so you don’t need a programmer, a debug probe, or any extra software. Just a USB cable.

  1. Download the latest firmware.uf2 from the Releases page (look for a tag like firmware-v0.8.0). Pick the build that matches your board revision:
    • hw-rev1 for the v1.0 board
    • hw-rev2 for the v1.1 board
  2. With the Pico 2 unplugged, press and hold the BOOTSEL button on top of the module.
  3. Plug the USB cable in while still holding BOOTSEL, then release.
  4. A USB mass-storage drive named RP2350 appears on your host.
  5. Drag-and-drop the firmware.uf2 onto that drive (or cp/Copy-Item from a shell).
  6. The drive vanishes; the Pico 2 reboots into the new firmware automatically.

That’s it — no command-line flashing tool required.

Tip

If the RP2350 drive doesn’t show up, the Pico 2 didn’t enter bootloader mode. Unplug, hold BOOTSEL, plug back in. Don’t release BOOTSEL until you see the drive.

Step 3: Verify

Confirm the firmware is alive by running gallo version. See Verifying Your Device for the expected output and what each field means.

When Things Go Wrong

  • Drive doesn’t appear in BOOTSEL mode — try a different USB cable (some “charge-only” cables don’t carry data) or a different USB port.
  • gallo can’t find the device after flashing — on Linux you may need a udev rule; on Windows the WinUSB driver may need to be installed via Zadig. See USB & OS Notes.
  • You flashed hw-rev1 onto a v1.1 board (or vice versa) — no damage done; just re-enter BOOTSEL and flash the right build.