PCB2.3 JF

RODIA Pathfinder

AI-generated visualisation of the PCB2.3 board: front (left) and back (right).

RODIA Pathfinder is the first iteration of a custom RP2040 flight computer for Trinity, the hybrid rocket-drone vehicle of the student team Manhattan Rockets (Czech Rocket Society). It is a 40 × 40 mm, two-layer board designed in KiCad and manufactured and assembled by JLCPCB.

Pathfinder is not meant to fly. It exists to prove the core of the design in hardware (MCU, power, flash, barometer, pyro channel) before the more demanding RODIA (Rocket Onboard Drone Interface Avionics) board is built.

Full documentation (Czech, 19 pages): MR_PCB2_DOCUM_FINAL.pdf

Board overview

3D view, top	3D view, bottom

Full schematic: images/schematic.pdf

Status

Verified on hardware

• Power from USB-C and from a 2S battery
• Firmware upload over USB (BOOT button, mass-storage mode)
• BMP388 barometer: 25 Hz logging, ±0.1 m noise
• BNO085 orientation sensor (on the extension board) sharing the I2C bus with the BMP388

Known issues (input for the next revision)

• J3 silkscreen GPIO labels are shifted by two (see rodia-pathfinder/AVIONICS.md)
• No SWD pads, so no hardware debugging
• Linear regulator dissipates ~0.9 W from a full 3S pack at 100 mA; a switching regulator would remove this
• SD card module on the extension board needs 5 V, which is not available in flight
• No flyback diode on the pyro channel: fine for a resistive e-match, not for inductive loads

Repository structure

.
├── README.md
├── MR_PCB2_DOCUM_FINAL.pdf                 full Pathfinder documentation (Czech)
├── images/                                 renders, schematic blocks, copper layers
├── rodia-pathfinder/                       design files
│   ├── AVIONICS.md                         pin map, SPI rules, firmware build, hardware status
│   ├── PCB2.3_JF/                          main board: KiCad project + JLCPCB production files
│   ├── Sensor_board_1.2/                   extension board: BNO085, SD card, LEDs, buzzer
│   └── datasheets+components+min-design/   datasheets, component lists, RP2040 minimal reference design
└── rodia/                                  the next board
    ├── RODIA_project_brief_EN.pdf          motivation, idea, requirements
    └── RODIA_block_diagram.pdf / .odg      simplified system diagram

What comes next: RODIA

Trinity flies a ballistic rocket ascent followed by a powered, controlled drone descent. The drone flight controller handles the descent, but its firmware only provides filtered data tuned for propeller flight, and its accelerometer is close to its range limit under rocket loads. RODIA is a second, independent flight computer that connects to the drone flight controller, follows drone-FC mechanical standards, logs raw sensor data, talks to the ground station and can carry out the critical functions (parachute deployment) on its own if the drone FC fails. See rodia/RODIA_project_brief_EN.pdf.

About

Designed by Vít Krejčí (avionics, Manhattan Rockets, a student rocketry team operating under the Czech Rocket Society).

Datasheets in rodia-pathfinder/datasheets+components+min-design/ belong to their respective manufacturers and are included for reference only.