This is my first PCB design. It's a controller board that drives two high-torque hobby servos from a 2S Li-ion pack. I'm planning to order it from JLCPCB with assembly, so I'd really appreciate a review before I send it off, especially on the power side.
**Board overview**
- 2 layer
- 2S 18650 input (6.0–8.4 V) on a screw terminal
- Three MP1584 buck modules: 5 V for the MCU, and a separate 6 V rail for each servo so one stalling servo can't drag down the other or the MCU
- Each servo rail: buck → series Schottky → 470 µF polymer cap → 3-pin servo header
- Battery voltage sense through a 12k/5.6k divider + 10 µF into an ADC pin
- Illuminated pushbutton (input + LED) on a 4-pin terminal
- VIN is a top-layer pour, GND is poured on both layers
**Main components**
- MCU: Seeed XIAO ESP32-S3
- Regulators: 3× MP1584 modules (D-SUN style, through-hole mounted)
- Servos: 2× DS3218 Pro (4.8–6.8 V, ~2.5 A stall each)
- Diodes: 30 V / 5 A Schottky, SOD-128
- Bulk caps: 3× 470 µF / 25 V polymer (input + each servo rail)
**Manufacturing**
JLCPCB will fabricate the board and assemble the caps, diodes, resistors, terminals and headers. I'll hand-solder the buck modules and the XIAO.
**Part placement**
- Bottom: input terminal + input cap
- Middle: the three buck modules sitting on the VIN pour
- Top left: servo headers, their bulk caps and the Schottkys
- Top right: XIAO, with the battery divider and button terminal next to it
Any feedback is appreciated, thanks!