PCB Revisions¶

Rev	Status	Size	Notes
1	Prototype (never ordered)	—	Feasibility study
2	Delivered	114mm round	Dimension error (57mm radius instead of 75mm diameter); electrical test only
3	Delivered, has bugs	88mm round	Target design; not usable
4	Delivered, superseded	88mm round	Target design
5	Delivered, currently deployed	88mm round	4× TDM microphones (ADAU7118), WROOM-1U (external antenna), USB-C solder pads, fixed SD slot orientation

Rev. 5 (current)¶

Same footprint as Rev. 4 (88mm round), fits the existing enclosure. Changes:

Chip: ESP32-S3-WROOM-1U-N16R8 (external antenna) — Rev. 4 used the internal-antenna variant
Microphones: 4× SPH0641LU4H-1 (PDM) → ADAU7118 (PDM→TDM converter) → TDM straight into the ESP32-S3's I2S peripheral, enabling beamforming
Buttons remapped: the TDM mic lines took over GPIOs previously used for PTT/Vol+/Vol− — rewired to PTT=GPIO40, Vol+=GPIO39, Vol−=GPIO18 (Mute stays GPIO11)
Status LED: its own pin (GPIO1); a second, purely passive power LED was added, wired directly to 3.3V/GND
LED ring: SK6812MINI-RV (was SK6812MINI-E on Rev. 4), driven through a level shifter — unlike the plain 3.3V-compatible SK6812-Mini-E used before it
USB-C removed: replaced with solder pads for an external cable to a panel-mount USB-C connector in the enclosure
Speaker, BME680 sensor, and the LD2410 radar are unchanged from Rev. 4

88mm round, one side slightly flattened for USB-C, 4-layer (F.Cu / GND / 3.3V / B.Cu), ENIG.