L-shape opens toward bottom-left; the two long outer edges carry the jack
rows (CV top, MIDI right, ~52 mm each), USB-C on the short left edge beside
the battery. Top arm = all CV analog + switching converters (noise kept
far from radio); right arm = digital + MIDI + RM2 at the bottom-right
corner for best antenna keepout. Target 2000 mAh cell -> ~70x58 mm
bounding box, 50x35 mm notch. Renumbered build order.
BQ24075 (single-cell charger + power-path SYS): USB present -> powers
device + charges cell; USB absent -> battery takes over seamlessly.
System rail becomes SYS (~3.0-4.2V battery domain); existing converters
already accept it (3.3V is buck-boost RT6150B so survives sag). MAX17048
fuel gauge on I2C1 for SoC on OLED. Power budget updated (~200-400mA
from SYS, charge limited to ~500mA on USB 2.0). ~5-8h on a 1500-2000mAh
cell. Connection table, BOM, risks, build order updated.
NOTE: hardware/netlist.net still references +5V rails; needs the SYS/
BQ24075/BAT/MAX17048 nets added — regenerate on request.
Use the pre-certified Raspberry Pi Radio Module 2 (RM2, CYW43439 + PCB
antenna) instead of a bare CYW43439 — eliminates RF design + cert; only
the datasheet antenna keepout remains. Dev/test on RP2040 (Pico W),
product on RP2350; firmware dual-builds via embassy-rp features.
nils