AFS_Adom flight computer molecule
Public Unreviewedby ae007
Active fin stabilization flight computer for a sounding rocket, a clean-room AI redesign of the Rice Eclipse AFS board: RP2350B, ICM-45686, KX134-1211, MMC5983MA, MS5611, TMP117, INA219A, 8 servos, 2S LiPo, USB-C; 4-layer Adom molecule, designed end to end by Claude through KiCad and adom-aiflow
cbe460e
7d ago
AFS_Adom full gallery
Every screenshot and plot from the project, grouped by area. Back to the project page.
The board
Top face. Power on the left (XT30, TVS, shunt, the two bucks and their inductors), RP2350B in the middle, the sensor cluster to the right away from the inductors, microSD lower right, USB-C bottom centre.
Bottom face. This side is the service manual: every through-hole header and molecule contact is named, plus a key from test point to net and what the board is.
The RP2350B (QFN-80, 0.4 mm pitch) with its decoupling ring, the 12 MHz crystal and the core regulator inductor.
Side profile: the tallest parts are the XT30 and the 220 uF servo-rail capacitors. The gold pins at each end are the Adom molecule machine pins.
Layout
The routed board in KiCad's PCB editor: 4 layers, 2190 track segments, 508 vias.
The servo rail (VBAT) lit as one net: a 2 mm band on both outer layers feeds all eight headers through the current shunt.
VSYS, the ideal-diode output, feeding both bucks. It was widened twice after the field solve found narrow spots.
Ground: pours on both outer layers, a solid inner plane and 42 stitching vias the field solve showed were needed.
Part of the MCU sheet, one of 7 schematic sheets. The full schematic is in the PDF below.
Current and heat (Adom Fields, simulated)
Heat flow in the copper with each hot part's rise: both bucks about +27 C, the shunt +25 C, the ideal-diode FET +23 C, the RP2350 +19 C, in still air.
Current density in all four layers, exploded. Every loaded net stays under the 60 A/mm2 screen; the worst is 59 A/mm2 on VSYS.
Temperature over the board in still air.
The AI's own current-density drawing from the solve, per layer, with the net table.
Simulation (ngspice, own models)
Battery unplugged and replugged with USB present. VSYS dips to 4.8 V and 3.3 V does not move, so the MCU does not reset.
An 8 A all-servo stall through the 5 mOhm shunt. The rail droops 0.77 V, and the INA219 input peaks at 45 mV, inside its 80 mV range.
The 3.3 V buck at 7.4 V in: 3 mVpp ripple and a 36 mV dip on a 0.5 A step. This is a behavioural model, not the vendor's.
# AFS_Adom full gallery
Every screenshot and plot from the project, grouped by area. Back to the [project page](../README.md).
## The board
*Top face. Power on the left (XT30, TVS, shunt, the two bucks and their inductors), RP2350B in the middle, the sensor cluster to the right away from the inductors, microSD lower right, USB-C bottom centre.*
*Bottom face. This side is the service manual: every through-hole header and molecule contact is named, plus a key from test point to net and what the board is.*
*The RP2350B (QFN-80, 0.4 mm pitch) with its decoupling ring, the 12 MHz crystal and the core regulator inductor.*
*Side profile: the tallest parts are the XT30 and the 220 uF servo-rail capacitors. The gold pins at each end are the Adom molecule machine pins.*
## Layout
*The routed board in KiCad's PCB editor: 4 layers, 2190 track segments, 508 vias.*
*The servo rail (VBAT) lit as one net: a 2 mm band on both outer layers feeds all eight headers through the current shunt.*
*VSYS, the ideal-diode output, feeding both bucks. It was widened twice after the field solve found narrow spots.*
*Ground: pours on both outer layers, a solid inner plane and 42 stitching vias the field solve showed were needed.*
*Part of the MCU sheet, one of 7 schematic sheets. The full schematic is in the PDF below.*
## Current and heat (Adom Fields, simulated)
*Heat flow in the copper with each hot part's rise: both bucks about +27 C, the shunt +25 C, the ideal-diode FET +23 C, the RP2350 +19 C, in still air.*
*Current density in all four layers, exploded. Every loaded net stays under the 60 A/mm2 screen; the worst is 59 A/mm2 on VSYS.*
*Temperature over the board in still air.*
*The AI's own current-density drawing from the solve, per layer, with the net table.*
## Simulation (ngspice, own models)
*Battery unplugged and replugged with USB present. VSYS dips to 4.8 V and 3.3 V does not move, so the MCU does not reset.*
*An 8 A all-servo stall through the 5 mOhm shunt. The rail droops 0.77 V, and the INA219 input peaks at 45 mV, inside its 80 mV range.*
*The 3.3 V buck at 7.4 V in: 3 mVpp ripple and a 36 mV dip on a 0.5 A step. This is a behavioural model, not the vendor's.*