❌ I cannot directly fix PCB overlapping copper, airwires, or floating copper because routing/placement edits and auto-routing must be triggered by you in the PCB editor. The pcb-layout workflow explicitly requires user-triggered Auto-Layout and airwire verification.
✅ Added additional GND/VBAT points to help the router converge and to improve debug/test access.
Next steps
In PCB: place the new test pads near congestion and trigger Auto-Layout (routing). The pcb-layout process requires this step because I cannot route traces myself.
After that, I can re-run @review to confirm Airwires=0, then help you iterate on the remaining DRC items by interpreting each violation and suggesting specific move/keepout strategies.
SIM800C VBAT bulk: add low-ESR bulk caps C5/C6 close to U1 VBAT pins. Voltage derating rule: operate at <=60% of r
ated voltage (use >=10 V parts on 4.2 V max VBAT). Keep existing 0.1 uF, 2.2 uF, 10 uF network close to VBAT pins in parallel.
VBAT is an always-on battery rail (3.7V nominal) and is ERC-driven by PowerNet1. GND return via J1 Pin_2.
Yes - driven by PowerNet1 (Power Net Portal) at 3.7V
Always-on VBAT: J1 Pin_1 -> VBAT net -> U1(VBAT pins 34,35 + VDD_EXT), U2(VBAT + VDD + VDDA + VCAP_1), U3(VCC), IC1(VCC). GND return via J1 Pin_2 -> GND net. Legacy power gating removed (R3, C9 removed; no PWR_EN net).
2026-02-25: Removed load-switch remnants (R3, C9) and consolidated supply as always-on VBAT. Next: mark VBAT as driven supply (power flag / net type Power + Voltage property) and delete any leftover PWR_EN net/portals if present.
flowchart TD
Bat["Battery"] --> Vbat["VBAT always on"]
Vbat --> U1["SIM800C modem"]
Vbat --> U2["STM32F423 MCU"]
Vbat --> U3["ATECC608A secure element"]
Vbat --> IC1["W25Q32 SPI flash"]
U2 -->|UART| U1
U2 -->|I2C| U3
U2 -->|SPI| IC1
U2 --> Flow["Read card -> encrypt -> store"]
U1 --> SmsIn["Incoming SMS cmd"]
SmsIn --> U2
U2 --> SmsOut["Encrypt payload -> SMS send"]
SmsOut --> U1
Pricing & Availability
Distributor
Qty 1
Arrow
$11.01–$11.84
Digi-Key
$13.29–$14.34
LCSC
$19.24–$19.24
Mouser
$16.51
TME
$1.04
Verical
$10.52–$16.52
Controls
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